http://www.cfd-online.com/W/index.php?title=Special:Contributions/Roberthealy1&feed=atom&limit=50&target=Roberthealy1&year=&month=CFD-Wiki - User contributions [en]2016-10-21T00:54:18ZFrom CFD-WikiMediaWiki 1.16.5http://www.cfd-online.com/Wiki/CodesCodes2008-05-05T21:30:41Z<p>Roberthealy1: /* Solvers */</p>
<hr />
<div>An overview of both free and commercial CFD software. Here you will find short descriptions of codes along with links to resources.<br />
<br />
'''Note to contributers:''' Please try to keep descriptions short and to the point (approximately 200 words) and avoid long lists of features or capabilities. Also keep in mind that all contributions are considered to be released under the GNU Free Documentation License 1.2 (see [[Project:Copyrights]] for details). Also note that all information should be verifiable and objective truths that also competitors to the code in question will agree upon. This is especially important if you are an employee of the company selling the code. See the [[CFD-Wiki:Policy]] for further information.<br />
<br />
== Free codes ==<br />
<br />
This section lists codes that are in the public domain, and codes that are available under GPL, BSD or similar licenses.<br />
<br />
=== Solvers ===<br />
* Applied Computational Fluid Dynamics -- [http://www.partenovcfd.com Solver homepage]<br />
* CFD2k -- [http://www.cfd2k.eu/ CFD2k: a 2D-solver for compressible ideal gases - homepage]<br />
* Channelflow -- [http://www.cns.gatech.edu/channelflow/ Channelflow: a spectral Navier-Stokes simulator in C++ homepage]<br />
* Code_Saturne -- [http://rd.edf.com/code_saturne Code_Saturne homepage]<br />
* ADFC -- [http://adfc.sourceforge.net/index.html ADFC homepage]<br />
* Diagonalized Upwind Navier Stokes -- [http://duns.sourceforge.net DUNS homepage]<br />
* [[Dolfyn]] -- [http://www.dolfyn.net/dolfyn/index_en.html dolfyn a 3D unstructured general purpose solver - homepage]<br />
*[[Edge]] -- [http://www.foi.se/edge Edge homepage: 2D & 3D compressible RANS / Euler flow solver on unstructured and hybrid grids]<br />
*[[ELMER]] -- [http://www.csc.fi/elmer/ ELMER homepage]<br />
* [[FDS]] -- [http://www.fire.nist.gov/fds/ FDS homepage]<br />
* Featflow -- [http://www.featflow.de Featflow homepage]<br />
* Femwater -- [http://www.cee.odu.edu/model/femwater.php Femwater code]<br />
* FreeFEM -- [http://www.freefem.org FreeFEM homepage]<br />
*[[Gerris Flow Solver]] -- [http://gfs.sourceforge.net/ Gerris Flow Solver homepage]<br />
* IMTEK Mathematica Supplement (IMS) -- [http://www.imtek.uni-freiburg.de/simulation/mathematica/IMSweb/ IMTEK Mathematica Supplement (IMS) homepage]<br />
* iNavier -- [http://inavier.sourceforge.net/ iNavier Solver Home Page]<br />
* ISAAC -- [http://isaac-cfd.sourceforge.net ISAAC Home Page]<br />
* MFIX -- [http://www.mfix.org Computational multiphase flow homepage]<br />
*[[NaSt2D-2.0]] -- [http://home.arcor.de/drklaus.bauerfeind/nast/eNaSt2D.html NaSt2D-2.0 homepage]<br />
*[[NSC2KE]] -- [http://www-rocq1.inria.fr/gamma/cdrom/www/nsc2ke/eng.htm NSC2KE homepage]<br />
* NUWTUN -- [http://nuwtun.berlios.de NUWTUN Home Page]<br />
*[[OpenFlower]] -- [http://sourceforge.net/projects/openflower/ OpenFlower homepage]<br />
*[[OpenFOAM]] -- [http://www.openfoam.org/ OpenFOAM homepage]<br />
* OpenFVM -- [http://openfvm.sourceforge.net/ OpenFVM homepage]<br />
* PETSc-FEM -- [http://www.cimec.org.ar/petscfem PETSc-FEM homepage]<br />
* PP3D -- [http://www.featflow.de/ parpp3d++ homepage]<br />
* SLFCFD -- [http://slfcfd.sourceforge.net SLFCFD homepage]<br />
*[[SSIIM]] -- [http://folk.ntnu.no/nilsol/cfd/ CFD at NTNU]<br />
*[[Tochnog]] -- [http://tochnog.sourceforge.net Tochnog homepage]<br />
* Typhon solver -- [http://typhon.sf.net Typhon solver homepage]<br />
<br />
=== Grid generation ===<br />
*[[Delaundo]] -- [http://www.cerfacs.fr/~muller/delaundo.html Delaundo homepage]<br />
* GMSH -- [http://www.geuz.org/gmsh/ GMSH hompage]<br />
* NETGEN -- [http://www.hpfem.jku.at/netgen/ NETGEN homepage]<br />
* SALOME -- [http://www.salome-platform.org SALOME homepage]<br />
* TETGEN -- [http://tetgen.berlios.de/ TETGEN hompage]<br />
* CartGen -- [http://mehr.sharif.ir/~tav/cartgen.htm CartGen homepage]<br />
*[[Triangle]] -- [http://www.cs.cmu.edu/~quake/triangle.html Triangle homepage]<br />
* gridgen -- [http://www.marine.csiro.au/~sakov Pavel Sakov's homepage]<br />
<br />
=== Visualization ===<br />
*[[DISLIN]] -- [http://www.mps.mpg.de/dislin/server.html DISLIN homepage]<br />
* GMV -- [http://www-xdiv.lanl.gov/XCM/gmv/ GMV homepage]<br />
*[[Gnuplot]] -- [http://www.gnuplot.info/ gnuplot homepage]<br />
* GRI -- [http://gri.sourceforge.net/ GRI homepage]<br />
*[[Mayavi]] -- [http://mayavi.sourceforge.net/ MayaVi homepage]<br />
*[[OpenDX]] -- [http://www.opendx.org OpenDX homepage]<br />
*[[ParaView]] -- [http://www.paraview.org/HTML/Index.html ParaView homepage]<br />
*[[Tioga]] -- [http://www.kitp.ucsb.edu/~paxton/tioga.html Tioga homepage]<br />
*[[Vigie]] -- [http://www-sop.inria.fr/sinus/Softs/vigie.html Vigie homepage]<br />
*[[Visit]] -- [http://www.llnl.gov/visit Visit homepage]<br />
*[[vtk]] -- [http://www.vtk.org vtk homepage]<br />
*[[vtk.Net]] -- [http://vtkdotnet.sourceforge.net/ vtk.Net homepage]<br />
<br />
=== Miscellaneous ===<br />
<br />
*[[Engauge Digitizer]] -- [http://digitizer.sourceforge.net Engauge Digitizer homepage]<br />
*[[Ftnchek]] -- [http://www.dsm.fordham.edu/~ftnchek/ ftnchek homepage]<br />
*[[g3data]] -- [http://www.frantz.fi/software/g3data.php g3data homepage]<br />
* GIFMerge -- [http://www.the-labs.com/GIFMerge/ GIFMerge homepage]<br />
*[[Gifsicle]] -- [http://www.lcdf.org/~eddietwo/gifsicle/ Gifsicle homepage]<br />
*[[ImageMagick]] -- [http://www.imagemagick.org ImageMagick homepage]<br />
* nnbathy (natural neighbor interpolation) -- [http://www.marine.csiro.au/~sakov Pavel Sakov's home page]<br />
<br />
== Commercial codes ==<br />
<br />
=== Solvers ===<br />
* Applied Computational Fluid Dynamics -- [http://www.partenovcfd.com Solver homepage]<br />
* AcuSolve -- [http://www.acusim.com/ ACUSIM Software's homepage]<br />
* ADINA-F -- [http://www.adina.com/index.html ADINA's homepage]<br />
* ADINA-FSI -- [http://www.adina.com/index.html ADINA's homepage]<br />
* ANSWER -- [http://www.acricfd.com/ ACRi's homepage]<br />
*[http://www.cfd-online.com/W/index.php?title=CFD%2B%2B CFD++] -- [http://www.metacomptech.com Metacomp Techonlogies' homepage]<br />
* CFD2000 -- [http://www.adaptive-research.com/ Adaptive Research's homepage]<br />
*[[CFD-FASTRAN]] -- [http://www.esi-group.com/SimulationSoftware/advanced.html ESI Group's homepage]<br />
* CFD-ACE -- [http://www.esi-group.com/SimulationSoftware/advanced.html ESI Group's homepage]<br />
* CFdesign -- [http://www.cfdesign.com CFdesign's homepage]<br />
* CFX -- [http://www.ansys.com/ ANSYS homepage]<br />
* COMSOL -- [http://www.comsol.com/ COMSOL's homepage]<br />
* EFD -- [http://www.nika.biz/ Flomerics/NIKA homepage]<br />
*[[FENSAP-ICE]] -- [http://www.newmerical.com/ NTI' homepage]<br />
* FINE -- [http://www.numeca.be/ Numeca's homepage]<br />
* FIRE -- [http://www.avl.com/ AVL's homepage]<br />
*[[FLACS]] -- [http://www.gexcon.com/index.php?src=flacs/overview.html GexCon's homepage]<br />
* FLOW-3D -- [http://www.flow3d.com/ Flow Science's homepage]<br />
* FLOTHERM-- [http://www.flomerics.com Flomerics' homepage]<br />
* FLOVENT-- [http://www.flomerics.com Flomerics' homepage]<br />
* FLOWVISION -- [http://www.fv-tech.com FlowVision's homepage]<br />
*[[FLUENT]] -- [http://www.fluent.com Fluent's homepage]<br />
* FluSol -- [http://www.cfd-rocket.com FluSol's hompage]<br />
* Flowz--[http://www.zeusnumerix.com Zeus Numerix's homepage ]<br />
*[[J-FLO]] -- [http://www.newmerical.com NTI's homepage]<br />
* KINetics Reactive Flows -- [http://www.ReactionDesign.com Reaction Design's homepage]<br />
* KIVA--[http://www.lanl.gov/orgs/t/t3/codes/kiva.shtml Los Alamos homepage]<br />
*[[NOGRID FPM]] -- [http://www.no-grid.com NOGRIDS's homepage]<br />
* NX Electronic Systems Cooling -- [http://www.mayahtt.com/index.php?option=com_content&task=view&id=69&Itemid=237 MAYA's NX ESC page]<br />
* NX Advanced Flow -- [http://www.mayahtt.com/index.php?option=com_content&task=view&id=1&Itemid=115 MAYA HTT's NX Adv. Flow page]<br />
* NX Flow -- [http://www.mayahtt.com/index.php?option=com_content&task=view&id=2&Itemid=116 MAYA HTT's NX Flow page]<br />
*[[PHOENICS]] -- [http://www.cham.co.uk CHAM's homepage]<br />
* PumpLinx -- [http://www.simerics.com Simerics' homepage]<br />
* [[Siemens PLM Software CFD]] -- [http://www.plm.automation.siemens.com/en_us/products/nx/simulation/advanced/index.shtml Siemens PLM Software NX CAE page]<br />
*[[SPLASH]] -- [http://www.panix.com/~brosen SPLASH's homepage]<br />
*[[STAR-CD]] -- [http://www.cd-adapco.com CD-adapco's homepage]<br />
*[[STAR-CCM+]] -- [http://www.cd-adapco.com CD-adapco's homepage]<br />
*[[Tdyn]] -- [http://www.compassis.com CompassIS' homepage]<br />
* TMG-Flow -- [http://www.mayahtt.com/index.php?option=com_content&task=view&id=82&Itemid=283 MAYA HTT's CFD page]<br />
* Turb'Flow -- [http://www.fluorem.com Fluorem's hompage]<br />
<br />
=== Grid generation ===<br />
<br />
* ADINA-AUI -- [http://www.adina.com/index.html ADINA's homepage]<br />
* Centaur -- [http://www.centaursoft.com CentaurSoft homepage]<br />
*[[CFD-GEOM]] -- [http://www.esi-group.com/ ESI's homepage]<br />
*[[CFD-VISCART]] -- [http://www.esi-group.com/ ESI's homepage]<br />
* CFDExpert-GridZ --[http://www.zeusnumerix.com/ Zeus Numerix's homepage]<br />
*[[Gridgen]] -- [http://www.pointwise.com/ Pointwise's homepage]<br />
*[[ GridPro]] -- [http://www.gridpro.com/ PDC's homepage]<br />
* Harpoon -- [http://www.ensight.com/ CEI's homepage]<br />
* ICEM CFD -- [http://www.ansys.com/ ANSYS' homepage]<br />
* +ScanFE -- [http://www.simpleware.com/ Simpleware's homepage]<br />
<br />
=== Visualization ===<br />
<br />
* ADINA-AUI -- [http://www.adina.com/index.html ADINA's homepage]<br />
*[[CFD-VIEW]] -- [http://www.esi-group.com/ ESI's homepage]<br />
* CFX-Post -- [http://www.ansys.com/ ANSYS' homepage]<br />
* COVISE -- [http://www.visenso.de/ Visenso's homepage]<br />
* EnSight -- [http://www.ensight.com/ CEI's homepage]<br />
* Fieldview -- [http://www.ilight.com/ Intelligent Light's homepage]<br />
*[[Tecplot]] -- [http://www.tecplot.com/ Tecplot's homepage]<br />
*ViewZ -- [http://www.zeusnumerix.com/ Zeus Numerix's homepage]<br />
<br />
=== Systems ===<br />
<br />
* ADINA -- [http://www.adina.com/index.html ADINA's homepage]<br />
* Flowmaster -- [http://www.flowmaster.com/index.html Flowmaster's homepage]<br />
* Flownex -- [http://www.flownex.com/ Flownex's homepage]<br />
<br />
== Online tools and services ==<br />
<br />
*[[CFDNet]] -- [http://www.cfdnet.com/ CFDNet homepage]</div>Roberthealy1http://www.cfd-online.com/Wiki/Reynolds_numberReynolds number2007-08-23T19:24:58Z<p>Roberthealy1: /* Reynolds number as a ratio of time scales */</p>
<hr />
<div>The Reynolds number characterises the relative importance of inertial and viscous forces in a flow. It is important in determining the state of the [[flow]], whether it is [[laminar]] or [[turbulent]]. At high Reynolds numbers flows generally tend to be [[turbulent]], which was first recognized by [[Osborne Reynolds]] in his famous [[pipe flow experiments]]. Consider the [[momentum equation]] which is given below<br />
<br />
:<math><br />
\frac{\partial}{\partial t}\left( \rho u_i \right) +<br />
\frac{\partial}{\partial x_j}<br />
\left[ \rho u_i u_j + p \delta_{ij} \right] = \frac{\partial}{\partial x_j} \tau_{ij}<br />
</math><br />
<br />
The terms on the right are the [[inertial forces]] and those on the left correspond to [[viscous forces]]. If <math>U</math>, <math>L</math>, <math>\rho</math> and <math>\mu</math> are the reference values for [[velocity]], [[length]], [[density]] and [[dynamic viscosity]], then<br />
<br />
inertial force ~ <math>\frac{\rho U^2}{L}</math><br />
<br />
viscous force ~ <math>\frac{\mu U}{L^2}</math><br />
<br />
Their ratio is the Reynolds number, usually denoted as <math>Re</math><br />
<br />
:<math><br />
Re = \frac{\mbox{inertial force}}{\mbox{viscous force}} = \frac{\rho U L}{\mu}<br />
</math><br />
<br />
In terms of the kinematic viscosity<br />
<br />
:<math><br />
\nu = \frac{\mu}{\rho}<br />
</math><br />
<br />
the Reynolds number is given by<br />
<br />
:<math><br />
Re = \frac{U L}{\nu}<br />
</math><br />
<br />
==Reynolds number as a ratio of time scales==<br />
<br />
Consider an impulsively started flat plate moving in its own plane with [[velocity]] <math>U</math>. Due to the [[no-slip condition]] on the plate a [[boundary layer]] gradually develops on the plate. At time <math>t</math>, the thickness of the [[boundary layer]] is of the order of <math>\sqrt{\nu t}</math> (see Batchelor(1967), section 4.3). Let <math>L</math> be the [[characteristic length scale]]. The time taken for [[viscous]] and [[convective]] effects to travel a distance <math>L</math> is<br />
<br />
:<math><br />
T_{v} = \frac{L^2}{\nu}<br />
</math><br />
<br />
and<br />
<br />
:<math><br />
T_{c} = \frac{L}{U}<br />
</math><br />
<br />
The ratio of viscous to convective time scales is<br />
<br />
:<math><br />
\frac{ T_{v} }{ T_{c} } = \frac{(L^2/\nu)}{(L/U)} = \frac{UL}{\nu} = Re<br />
</math><br />
<br />
Thus the Reynolds number is a measure of the viscous and convective time scales. A large Reynolds number means that viscous effects propagate slowly into the [[fluid]]. This is the reason why boundary layers are thin in high Reynolds number flows because the fluid is being convected along the [[flow]] direction at a much faster rate than the spreading of the [[boundary layer]], which is normal to the [[flow]] direction.<br />
<br />
==References==<br />
*{{reference-book | author=Batchelor G K | year=1967 | title=An Introduction to Fluid Dynamics | rest=Cambridge University Press}}<br />
<br />
[[Category: Dimensionless parameters]]</div>Roberthealy1http://www.cfd-online.com/Wiki/Reynolds_numberReynolds number2007-08-23T19:23:43Z<p>Roberthealy1: Removed POV and added internal links</p>
<hr />
<div>The Reynolds number characterises the relative importance of inertial and viscous forces in a flow. It is important in determining the state of the [[flow]], whether it is [[laminar]] or [[turbulent]]. At high Reynolds numbers flows generally tend to be [[turbulent]], which was first recognized by [[Osborne Reynolds]] in his famous [[pipe flow experiments]]. Consider the [[momentum equation]] which is given below<br />
<br />
:<math><br />
\frac{\partial}{\partial t}\left( \rho u_i \right) +<br />
\frac{\partial}{\partial x_j}<br />
\left[ \rho u_i u_j + p \delta_{ij} \right] = \frac{\partial}{\partial x_j} \tau_{ij}<br />
</math><br />
<br />
The terms on the right are the [[inertial forces]] and those on the left correspond to [[viscous forces]]. If <math>U</math>, <math>L</math>, <math>\rho</math> and <math>\mu</math> are the reference values for [[velocity]], [[length]], [[density]] and [[dynamic viscosity]], then<br />
<br />
inertial force ~ <math>\frac{\rho U^2}{L}</math><br />
<br />
viscous force ~ <math>\frac{\mu U}{L^2}</math><br />
<br />
Their ratio is the Reynolds number, usually denoted as <math>Re</math><br />
<br />
:<math><br />
Re = \frac{\mbox{inertial force}}{\mbox{viscous force}} = \frac{\rho U L}{\mu}<br />
</math><br />
<br />
In terms of the kinematic viscosity<br />
<br />
:<math><br />
\nu = \frac{\mu}{\rho}<br />
</math><br />
<br />
the Reynolds number is given by<br />
<br />
:<math><br />
Re = \frac{U L}{\nu}<br />
</math><br />
<br />
==Reynolds number as a ratio of time scales==<br />
<br />
Consider an impulsively started flat plate moving in its own plane with [[velocity]] <math>U</math>. Due to the [[no-slip condition]] on the plate a [[boundary layer]] gradually develops on the plate. At time <math>t</math>, the thickness of the [[boundary layer]] is of the order of <math>\sqrt{\nu t}</math> (see Batchelor(1967), section 4.3). Let <math>L</math> be the [[characteristic length scale]]. The time taken for [[viscous]] and [[convective]] effects to travel a distance <math>L</math> is<br />
<br />
:<math><br />
T_{v} = \frac{L^2}{\nu}<br />
</math><br />
<br />
and<br />
<br />
:<math><br />
T_{c} = \frac{L}{U}<br />
</math><br />
<br />
The ratio of viscous to convective time scales is<br />
<br />
:<math><br />
\frac{ T_{v} }{ T_{c} } = \frac{(L^2/\nu)}{(L/U)} = \frac{UL}{\nu} = Re<br />
</math><br />
<br />
Thus the Reynolds number is a measure of the viscous and convective time scales. A large Reynolds number means that viscous effects propagate slowly into the [[fluid]]. This is the reason why boundary layers are thin in high Reynolds number flows because the fluid is being convected along the flow direction at a much faster rate than the spreading of the boundary layer, which is normal to the flow direction.<br />
<br />
==References==<br />
*{{reference-book | author=Batchelor G K | year=1967 | title=An Introduction to Fluid Dynamics | rest=Cambridge University Press}}<br />
<br />
[[Category: Dimensionless parameters]]</div>Roberthealy1http://www.cfd-online.com/Wiki/Talk:Ansys_FAQTalk:Ansys FAQ2007-08-21T22:42:22Z<p>Roberthealy1: Criticism of the ANSYS FAQ</p>
<hr />
<div>== Discussion regarding "Ansys FAQ" ==<br />
Hi,<br />
<br />
I really dislike this entry. I don't feel that it is in accordance with ''any'' of the [[CFD-Wiki:Policy ]] community guidelines, for instance it is not NPOV, I cannot verify it (no references or citations are provided) and I have no idea whether ANSYS may consider this information proprietary. <br />
<br />
I think that, at best it should be zoned to a forum of it's own and removed from the educational resource that is CFD-Wiki.<br />
<br />
Any opinions appreciated!<br />
<br />
--[[User:Roberthealy1|Roberthealy1]] 16:42, 21 August 2007 (MDT)</div>Roberthealy1http://www.cfd-online.com/Wiki/User:Roberthealy1User:Roberthealy12007-08-15T17:00:57Z<p>Roberthealy1: All about me</p>
<hr />
<div>{{userboxtop}}<br />
{{user Ireland}}<br />
{{user en}}<br />
{{User Renewable Energy}}<br />
{{User:KyraVixen/Userboxes/browser:PrefersFirefox}}<br />
{{user:UBX/chess}}<br />
{{userboxbottom}}<br />
<br />
<br />
== Me, Myself and I ==<br />
I am a graduate Mechanical Engineer from [http://www.nuigalway.ie/ National University of Ireland, Galway]. I spent three years at the [http://www.ncbes.ie/ National Centre of Biomedical Engineering and Science] on a research project on [[laminar flow]] over [http://en.wikipedia.org/wiki/Endothelial_cells endothelial cells]. Unfortunately, this project has been discontinued for a variety of reasons, primarily due to lack of funding. Thankfully, before I left I was granted my first [[patent]] for a [[technology]] to harness energy from ocean [[waves]].<br />
<br />
My interests are computer programming, fluid dynamics, and education. I am a fervent believer that fluid dynamics is under-appreciated and under-used in understanding the world around us. I believe that this project may be a huge benefit to students, educators, engineers and scientists (first) and as it grows, it will become of interest to the general public.<br />
<br />
I am currently looking for a job (any job) as a [[Mechanical Engineer]] if any kind person is offering...<br />
<br />
[[User:Roberthealy1|Roberthealy1]] 11:00, 15 August 2007 (MDT)</div>Roberthealy1http://www.cfd-online.com/Wiki/Alternating_direction_implicit_(ADI)_methodAlternating direction implicit (ADI) method2007-08-14T19:49:35Z<p>Roberthealy1: </p>
<hr />
<div>== Concept ==<br />
A common method of solving an [[elliptic problem]] is to add a term containing [[first derivative]] of time to the equation and solve the resulting [[parabolic equation]] until a [[steady state]] is reached. At this stage, the [[time derivative]] is zero and the solution represents the original problem.<br />
<br />
<br />
----<br />
<i> Return to [[Numerical methods | Numerical Methods]] </i></div>Roberthealy1http://www.cfd-online.com/Wiki/Ahmed_bodyAhmed body2007-08-14T19:47:04Z<p>Roberthealy1: /* Brief Description */</p>
<hr />
<div>== Brief Description ==<br />
[[Image:Ahmed.gif]]<br />
<br />
'''Fig. 1:''' Ahmed model. Dimensions are in mm (Fig. from [4])<br />
<br />
<br />
'''Description of the test case:'''<br />
The Ahmed body (Fig. 1) was first defined and its characteristics described in the experimental work of Ahmed [1]. Two configurations with slant angles of 25°and 35°are considered as a test case. For this configurations detailed LDA Measurements have been performed by Becker, Lienhart and Stoots [2,3] in the [[LSTM]] low-speed [[wind-tunnel]] with a cross-section of 1.87x1.4 m2 (width x height) with a bulk [[velocity]] of 40 m/s. The [[test-section]] of the [[wind-tunnel]] was 3/4 open (only ground plate present). The distance between the body and the plate representing the ground is 50 mm. <br />
<br />
A detailed test case description can be found [http://rz-ifh-pluto.rz.uni-karlsruhe.de/testcase/t4project.html here]<br />
<br />
== References: ==<br />
<br />
[1] S.R. Ahmed, G. Ramm, Some Salient Features of the Time-Averaged Ground Vehicle Wake, SAE-Paper 840300, 1984<br />
<br />
[2] H. Lienhart, S. Becker, Flow and Turbulence Structure in the Wake of a Simplified Car Model, SAE 2003 World Congress, SAE Paper 2003-01-0656, Detroit, Michigan, USA, 2003 <br />
<br />
[3] H. Lienhart, C. Stoots, S. Becker, Flow and Turbulence Structures in the Wake of a Simplified Car Model (Ahmed Model), DGLR Fach Symp. der AG STAB, Stuttgart University, 15-17 Nov., 2000 <br />
<br />
[4] C. Hinterberger, M. García-Villalba, W. Rodi, Large Eddy Simulation of flow around the Ahmed body. In "Lecture Notes in Applied and Computational Mechanics / The Aerodynamics of Heavy Vehicles: Trucks, Buses, and Trains", R. McCallen, F. Browand, J. Ross (Eds.), Springer Verlag, ISBN: 3-540-22088-7, 2004 <br />
<br />
[5] S. Krajnovic, L. Davidson, Large eddy simulation of the flow around a simplified car model, SAE 2004 World Congress, SAE Paper 2004-01-0227, Detroit, Michigan, USA, 2004 <br />
<br />
<br />
{{stub}}</div>Roberthealy1http://www.cfd-online.com/Wiki/Ahmed_bodyAhmed body2007-08-14T19:46:22Z<p>Roberthealy1: </p>
<hr />
<div>== Brief Description ==<br />
[[Image:Ahmed.gif]]<br />
<br />
'''Fig. 1:''' Ahmed model. Dimensions are in mm (Fig. from [4])<br />
<br />
<br />
'''Description of the test case:'''<br />
The Ahmed body (Fig. 1) was first defined and its characteristics described in the experimental work of Ahmed [1]. Two configurations with slant angles of 25°and 35°are considered as a test case. For this configurations detailed LDA Measurements have been performed by Becker, Lienhart and Stoots [2,3] in the [[LSTM]] low-speed [[wind-tunnel]] with a cross-section of 1.87x1.4 m2 (width x height) with a bulk [[velocity]] of 40 m/s. The [[test-section]] of the [[wind-tunnel]] was 3/4 open (only ground plate present). The distance between the body and the plate representing the ground is 50 mm. <br />
<br />
A detailed test case description can be found [http://rz-ifh-pluto.rz.uni-karlsruhe.de/testcase/t4project.html here]<br />
<br />
'''References:'''<br />
<br />
[1] S.R. Ahmed, G. Ramm, Some Salient Features of the Time-Averaged Ground Vehicle Wake, SAE-Paper 840300, 1984<br />
<br />
[2] H. Lienhart, S. Becker, Flow and Turbulence Structure in the Wake of a Simplified Car Model, SAE 2003 World Congress, SAE Paper 2003-01-0656, Detroit, Michigan, USA, 2003 <br />
<br />
[3] H. Lienhart, C. Stoots, S. Becker, Flow and Turbulence Structures in the Wake of a Simplified Car Model (Ahmed Model), DGLR Fach Symp. der AG STAB, Stuttgart University, 15-17 Nov., 2000 <br />
<br />
[4] C. Hinterberger, M. García-Villalba, W. Rodi, Large Eddy Simulation of flow around the Ahmed body. In "Lecture Notes in Applied and Computational Mechanics / The Aerodynamics of Heavy Vehicles: Trucks, Buses, and Trains", R. McCallen, F. Browand, J. Ross (Eds.), Springer Verlag, ISBN: 3-540-22088-7, 2004 <br />
<br />
[5] S. Krajnovic, L. Davidson, Large eddy simulation of the flow around a simplified car model, SAE 2004 World Congress, SAE Paper 2004-01-0227, Detroit, Michigan, USA, 2004 <br />
<br />
<br />
{{stub}}</div>Roberthealy1http://www.cfd-online.com/Wiki/Ahmed_bodyAhmed body2007-08-14T19:45:59Z<p>Roberthealy1: Great stub! Needs expansion</p>
<hr />
<div>== Brief Description ===<br />
[[Image:Ahmed.gif]]<br />
<br />
'''Fig. 1:''' Ahmed model. Dimensions are in mm (Fig. from [4])<br />
<br />
<br />
'''Description of the test case:'''<br />
The Ahmed body (Fig. 1) was first defined and its characteristics described in the experimental work of Ahmed [1]. Two configurations with slant angles of 25°and 35°are considered as a test case. For this configurations detailed LDA Measurements have been performed by Becker, Lienhart and Stoots [2,3] in the [[LSTM]] low-speed [[wind-tunnel]] with a cross-section of 1.87x1.4 m2 (width x height) with a bulk [[velocity]] of 40 m/s. The [[test-section]] of the [[wind-tunnel]] was 3/4 open (only ground plate present). The distance between the body and the plate representing the ground is 50 mm. <br />
<br />
A detailed test case description can be found [http://rz-ifh-pluto.rz.uni-karlsruhe.de/testcase/t4project.html here]<br />
<br />
'''References:'''<br />
<br />
[1] S.R. Ahmed, G. Ramm, Some Salient Features of the Time-Averaged Ground Vehicle Wake, SAE-Paper 840300, 1984<br />
<br />
[2] H. Lienhart, S. Becker, Flow and Turbulence Structure in the Wake of a Simplified Car Model, SAE 2003 World Congress, SAE Paper 2003-01-0656, Detroit, Michigan, USA, 2003 <br />
<br />
[3] H. Lienhart, C. Stoots, S. Becker, Flow and Turbulence Structures in the Wake of a Simplified Car Model (Ahmed Model), DGLR Fach Symp. der AG STAB, Stuttgart University, 15-17 Nov., 2000 <br />
<br />
[4] C. Hinterberger, M. García-Villalba, W. Rodi, Large Eddy Simulation of flow around the Ahmed body. In "Lecture Notes in Applied and Computational Mechanics / The Aerodynamics of Heavy Vehicles: Trucks, Buses, and Trains", R. McCallen, F. Browand, J. Ross (Eds.), Springer Verlag, ISBN: 3-540-22088-7, 2004 <br />
<br />
[5] S. Krajnovic, L. Davidson, Large eddy simulation of the flow around a simplified car model, SAE 2004 World Congress, SAE Paper 2004-01-0227, Detroit, Michigan, USA, 2004 <br />
<br />
<br />
{{stub}}</div>Roberthealy1http://www.cfd-online.com/Wiki/CFD-Wiki:Community_portalCFD-Wiki:Community portal2007-08-13T19:01:16Z<p>Roberthealy1: /* What needs to be done */</p>
<hr />
<div>This section is intended for people who work on adding content to the Wiki. So fellow CFD-Wikians, this is your page, private hideout, coffee room, coordination center, after-hours bar or whatever you want to use it for. If you still haven't contributed to the Wiki [[CFD-Wiki:Contribute something today|please do so today]]! We need your help and everyone is welcome to join our team of Wiki authors. <br />
<br />
==What's in the works==<br />
<br />
You who do significant additions to the Wiki, please add some information about your work, plans and progress here so that others can see what you are working on and perhaps help, monitor, come with suggestions and most importantly, be inspired by.<br />
<br />
* On May 21, 2007 we sent out a marketing email to all users of CFD Online. Hopefully this will make CFD-Wiki more well known and increase the number of additions --[[User:Jola|Jola]] 07:32, 21 May 2007 (MDT) <br />
<br />
* I am currently working on the [[Turbulence]] section with a new navigational structure and adding more text. --[[User:Jola|Jola]] 16:21, 17 June 2007 (MDT)<br />
<br />
== What needs to be done ==<br />
<br />
''Anything that you want!'' [http://en.wikipedia.org/wiki/Wikipedia:Be_bold Be bold] and just pick something that you feel that you can improve! If you need some help with good ideas on things to work on here are a few suggestions:<br />
<br />
* We have many turbulence models listed in the [[turbulence modeling]] section which still lack any description. Feel free to pick a model that you are familiar with and write a description of it. --[[User:Jola|Jola]] 01:50, 13 September 2005 (MDT)<br />
<br />
* The [[FAQ's | FAQ]] section is still very thin. If you are familiar with one of the larger CFD codes please consider adding a few questions and answers to the FAQ. --[[User:Jola|Jola]] 08:28, 13 September 2005 (MDT)<br />
<br />
* Editing! This is a constructive and collaborative work that improves with co-operation. -- [[User:Roberthealy1|Roberthealy1]] 16:48, 12 August 2007 (MDT)<br />
<br />
* Referencing! Dig out your old Fluid Dynamics, Thermodynamics and Heat Transfer textbooks. Make sure that the information you are providing for the world is verified and peer reviewed elsewhere. -- [[User:Roberthealy1|Roberthealy1]] 13:00, 13 August 2007 (MDT)<br />
<br />
* If you are an experienced CFD engineer and an expert in a special application area you are very welcome to start a [[Best practise guidelines|best practise guideline]] for your speciality. --[[User:Jola|Jola]] 10:44, 18 September 2005 (MDT)<br />
<br />
* ''... add your suggestions on what should be done here''<br />
<br />
==Other resources of interest==<br />
<br />
Here are a few links to pages that are of special interest for us CFD-Wikians:<br />
<br />
*[http://www.cfd-online.com/Forum/wiki.cgi Wiki Discussion Forum]<br />
*[[CFD-Wiki:FAQ| CFD-Wiki FAQ]]<br />
<br />
== CFD-Wikians - Who we are ==<br />
<br />
Add your name here if you make contributions to the wiki. <br />
<br />
The order is '''alphabetical (a - z)''' based on the '''user name'''.<br />
* [[User:Anand]] - www.iitm.ac.in<br />
* [[User:ABeevers]] - Adam Beevers<br />
* [[User:Aerodeepak]] - Deepak Thirumurthy<br />
* [[User:anurag]] - Anurag Sharma<br />
* [[User:bajjal]] - Bajjal Raghavendra<br />
* [[User:Ben]] - Ben D.<br />
* [[User:Discoganya]] - Sujit Kirpekar<br />
* [[User:ForMat]] - Matej Forman<br />
* [[User:ganesh]] - Ganesh N<br />
* [[User:harish]] - Harish Gopalan<br />
* [[User:jasond]] - Jason D.<br />
* [[User:jola]] - Jonas Larsson<br />
* [[User:kiranc]] - Kiran Chutkey<br />
* [[User:mirzapopovac]] - Mirza Popovac<br />
* [[User:Michail]] - Michail Kirichkov<br />
* [[User:Pavitran]] - Pavitran. D<br />
* [[User:praveen]] - Praveen. C<br />
* [[User:prokol]] - www.my-area.net<br />
* [[User:Roberthealy1]] - Robert Healy<br />
* [[User:Robkunz]] - Rob Kunz<br />
* [[User:s2vivek]] - vivekanandu.sakilam<br />
* [[User:sharonmshepard]] - Sharon Shepard<br />
* [[user:Sachinshendge]] - Sachin Shendge<br />
* [[User:Si]] - Simon Hubbard<br />
* [[User:snegan]] - Suriyanarayanan P<br />
* [[User:Suneesh]] - Suneesh S.S.<br />
* [[User:Toschi]] - Federico Toschi<br />
* [[User:Tsaad]] - [http://jedi.knows.it Tony Saad]<br />
* [[User:zxaar]] - Arjun Yadav</div>Roberthealy1http://www.cfd-online.com/Wiki/CFD-Wiki:Community_portalCFD-Wiki:Community portal2007-08-13T19:00:13Z<p>Roberthealy1: /* What needs to be done */</p>
<hr />
<div>This section is intended for people who work on adding content to the Wiki. So fellow CFD-Wikians, this is your page, private hideout, coffee room, coordination center, after-hours bar or whatever you want to use it for. If you still haven't contributed to the Wiki [[CFD-Wiki:Contribute something today|please do so today]]! We need your help and everyone is welcome to join our team of Wiki authors. <br />
<br />
==What's in the works==<br />
<br />
You who do significant additions to the Wiki, please add some information about your work, plans and progress here so that others can see what you are working on and perhaps help, monitor, come with suggestions and most importantly, be inspired by.<br />
<br />
* On May 21, 2007 we sent out a marketing email to all users of CFD Online. Hopefully this will make CFD-Wiki more well known and increase the number of additions --[[User:Jola|Jola]] 07:32, 21 May 2007 (MDT) <br />
<br />
* I am currently working on the [[Turbulence]] section with a new navigational structure and adding more text. --[[User:Jola|Jola]] 16:21, 17 June 2007 (MDT)<br />
<br />
== What needs to be done ==<br />
<br />
''Anything that you want!'' [http://en.wikipedia.org/wiki/Wikipedia:Be_bold Be bold] and just pick something that you feel that you can improve! If you need some help with good ideas on things to work on here are a few suggestions:<br />
<br />
* We have many turbulence models listed in the [[turbulence modeling]] section which still lack any description. Feel free to pick a model that you are familiar with and write a description of it. --[[User:Jola|Jola]] 01:50, 13 September 2005 (MDT)<br />
<br />
* The [[FAQ's | FAQ]] section is still very thin. If you are familiar with one of the larger CFD codes please consider adding a few questions and answers to the FAQ. --[[User:Jola|Jola]] 08:28, 13 September 2005 (MDT)<br />
<br />
* Editing! This is a constructive and collaborative work that improves with co-operation. -- [[User:Roberthealy1|Roberthealy1]] 16:48, 12 August 2007 (MDT)<br />
<br />
* Referencing! Dig out your old Fluid Dynamics, Thermodynamics and Heat Transfer textbooks. Make sure that the information you are providing for the world is verified and peer reviewed elsewhere. -- [[User:Roberthealy1|Roberthealy1]] 13:00, 13 August 2007 (MDT)<br />
<br />
* If you are an experienced CFD engineer and an expert in a special application area you are very welcome to start a [[Best practise guidelines|best practise guideline]] for your speciality. --[[User:Jola|Jola]] 10:44, 18 September 2005 (MDT)<br />
<br />
* ''... add your suggestions on what should be done here''<br />
<br />
* As commercial CFD codes become more and more capable, CFD design agencies are more and more pressed to reconsider the cost vs. benefit of developing and maintaining in-house codes. I have had many conversations on this topic with other CFD managers and practitioners - there is a lot to think about: We should have a discussion forum on this topic.<br />
[http://www.example.com link title]<br />
<br />
==Other resources of interest==<br />
<br />
Here are a few links to pages that are of special interest for us CFD-Wikians:<br />
<br />
*[http://www.cfd-online.com/Forum/wiki.cgi Wiki Discussion Forum]<br />
*[[CFD-Wiki:FAQ| CFD-Wiki FAQ]]<br />
<br />
== CFD-Wikians - Who we are ==<br />
<br />
Add your name here if you make contributions to the wiki. <br />
<br />
The order is '''alphabetical (a - z)''' based on the '''user name'''.<br />
* [[User:Anand]] - www.iitm.ac.in<br />
* [[User:ABeevers]] - Adam Beevers<br />
* [[User:Aerodeepak]] - Deepak Thirumurthy<br />
* [[User:anurag]] - Anurag Sharma<br />
* [[User:bajjal]] - Bajjal Raghavendra<br />
* [[User:Ben]] - Ben D.<br />
* [[User:Discoganya]] - Sujit Kirpekar<br />
* [[User:ForMat]] - Matej Forman<br />
* [[User:ganesh]] - Ganesh N<br />
* [[User:harish]] - Harish Gopalan<br />
* [[User:jasond]] - Jason D.<br />
* [[User:jola]] - Jonas Larsson<br />
* [[User:kiranc]] - Kiran Chutkey<br />
* [[User:mirzapopovac]] - Mirza Popovac<br />
* [[User:Michail]] - Michail Kirichkov<br />
* [[User:Pavitran]] - Pavitran. D<br />
* [[User:praveen]] - Praveen. C<br />
* [[User:prokol]] - www.my-area.net<br />
* [[User:Roberthealy1]] - Robert Healy<br />
* [[User:Robkunz]] - Rob Kunz<br />
* [[User:s2vivek]] - vivekanandu.sakilam<br />
* [[User:sharonmshepard]] - Sharon Shepard<br />
* [[user:Sachinshendge]] - Sachin Shendge<br />
* [[User:Si]] - Simon Hubbard<br />
* [[User:snegan]] - Suriyanarayanan P<br />
* [[User:Suneesh]] - Suneesh S.S.<br />
* [[User:Toschi]] - Federico Toschi<br />
* [[User:Tsaad]] - [http://jedi.knows.it Tony Saad]<br />
* [[User:zxaar]] - Arjun Yadav</div>Roberthealy1http://www.cfd-online.com/Wiki/Ratio_of_specific_heatsRatio of specific heats2007-08-13T18:57:16Z<p>Roberthealy1: This was well written and informative. However to be truly of encyclopaedic quality references are needed</p>
<hr />
<div>The ratio of [[specific heats]] (also known as ''adiabatic index''), usually denoted by <math>\gamma</math>, is the ratio of [[specific heat]] at constant [[pressure]] to the [[specific heat]] at constant [[volume]]. {{Fact}}<br />
<br />
:<math><br />
\gamma \equiv \frac{C_p}{C_v}<br />
</math><br />
<br />
The adiabatic index always exceeds unity; for a [[polytropic gas]] it is constant.{{fact}} For [[monatomic gas]] <math>\gamma=5/3</math>, and for [[diatomic gases]] <math>\gamma=7/5</math>, at ordinary [[temperatures]].{{fact}} For air its value is close to that of a diatomic gas, 7/5 = 1.4.{{fact}}<br />
<br />
Sometimes <math>\kappa</math> is used instead of <math>\gamma</math> to denote the [[specific heat ratio]].{{fact}}<br />
<br />
{{Stub}}</div>Roberthealy1http://www.cfd-online.com/Wiki/Adams_methodsAdams methods2007-08-13T18:53:03Z<p>Roberthealy1: What are BDF Methods?</p>
<hr />
<div>== Introduction ==<br />
<br />
Adams' methods are a subset of the family of [[multi-step methods]] used for the [[numerical integration]] of initial value problems in [[Ordinary Differential Equations]] (ODE's). [[Multi-step methods]] benefit from the fact that the computations have been going on for some time, and use previously computed values of the solution (BDF methods), or the right hand side (Adams' methods), to approximate the solution at the next step.<br />
<br />
Adams' methods begin by the integral approach,<br />
<br />
:<math><br />
y^\prime = f(t,y)<br />
</math><br />
<br />
<br />
:<math><br />
y(t_{N+1}) = y(t_{n}) + \int_{t_n}^{t_{n+1}} y^\prime (t) dt = y(t_{n}) + \int_{t_n}^{t_{n+1}} f(t,y(t)) dt<br />
</math><br />
<br />
Since <math>f</math> is unknown in the interval <math>t_n</math> to <math>t_{n+1}</math> it is approximated by an [[interpolating]] [[polynomial]] <math>p(t)</math> using the previously computed steps <math>t_{n},t_{n-1},t_{n-2} ...</math> and the current step at <math>t_{n+1}</math> if an implicit method is desired.{{fact}}<br />
<br />
== References ==<br />
<br />
?<br />
<br />
{{stub}}</div>Roberthealy1http://www.cfd-online.com/Wiki/2-D_vortex_in_isentropic_flow2-D vortex in isentropic flow2007-08-13T18:45:50Z<p>Roberthealy1: I think that this article may qualify as a stub, as it represents a POV; "one choice". An explanation of what the test is and what it can be used for would be worthwhile</p>
<hr />
<div>The test case involves [[convection]] of an [[isentropic]] [[vortex]] in [[inviscid flow]].<br />
The [[free-stream conditions]] are <br />
<br />
:<math><br />
\begin{matrix}<br />
\rho &=& 1 \\<br />
u &=& 0.5\\<br />
v &=& 0\\<br />
p &=& 1/\gamma<br />
\end{matrix}<br />
</math><br />
<br />
Perturbations are added to the [[free-stream]] in such a way that there is no<br />
[[entropy]] gradient in the [[flow-field]]. The perturbations are given by<br />
<br />
:<math><br />
\begin{matrix}<br />
(\delta u, \delta v) &=& \frac{\beta}{2\pi} \exp\left( \frac{1-r^2}{2}<br />
\right) [ -(y-y_o), (x-x_o) ] \\<br />
\rho &=& \left[ 1 - \frac{ (\gamma-1)\beta^2}{8\gamma\pi} \exp\left(<br />
1-r^2\right) \right]^{\frac{1}{\gamma-1}} \\<br />
p &=& \frac{ \rho^\gamma }{\gamma}<br />
\end{matrix}<br />
</math><br />
<br />
where <br />
<br />
:<math><br />
r = [ (x-x_o)^2 + (y-y_o)^2 ]^{1/2}<br />
</math><br />
<br />
is distance from the [[vortex]] center <math>(x_o, y_o)</math>. <br />
<br />
One choice for the domain and parameters is: <br />
<br />
:<math><br />
\Omega = [0,10] \times [-5,5], \quad<br />
(x_o, y_o) = (5,0), \quad<br />
\beta = 5<br />
</math><br />
<br />
As a result of [[isentropy]], the exact solution corresponds to a pure [[advection]]<br />
of the [[vortex]] at the [[free-stream velocity]]. Further details can be found in Yee et al. (1999).<br />
<br />
==References==<br />
<br />
*{{reference-paper | author=Yee, H-C., Sandham, N. and Djomehri, M., | year=1999 | title=Low dissipative high order shock-capturing methods using characteristic-based filters| rest=JCP, Vol. 150}}<br />
<br />
<br />
{{stub}}</div>Roberthealy1http://www.cfd-online.com/Wiki/2-D_vortex_in_isentropic_flow2-D vortex in isentropic flow2007-08-13T18:42:25Z<p>Roberthealy1: Provided interlinks between this page and other pages (many may require creation)</p>
<hr />
<div>The test case involves [[convection]] of an [[isentropic]] [[vortex]] in [[inviscid flow]].<br />
The [[free-stream conditions]] are <br />
<br />
:<math><br />
\begin{matrix}<br />
\rho &=& 1 \\<br />
u &=& 0.5\\<br />
v &=& 0\\<br />
p &=& 1/\gamma<br />
\end{matrix}<br />
</math><br />
<br />
Perturbations are added to the [[free-stream]] in such a way that there is no<br />
[[entropy]] gradient in the [[flow-field]]. The perturbations are given by<br />
<br />
:<math><br />
\begin{matrix}<br />
(\delta u, \delta v) &=& \frac{\beta}{2\pi} \exp\left( \frac{1-r^2}{2}<br />
\right) [ -(y-y_o), (x-x_o) ] \\<br />
\rho &=& \left[ 1 - \frac{ (\gamma-1)\beta^2}{8\gamma\pi} \exp\left(<br />
1-r^2\right) \right]^{\frac{1}{\gamma-1}} \\<br />
p &=& \frac{ \rho^\gamma }{\gamma}<br />
\end{matrix}<br />
</math><br />
<br />
where <br />
<br />
:<math><br />
r = [ (x-x_o)^2 + (y-y_o)^2 ]^{1/2}<br />
</math><br />
<br />
is distance from the [[vortex]] center <math>(x_o, y_o)</math>. One choice for the domain<br />
and parameters are <br />
<br />
:<math><br />
\Omega = [0,10] \times [-5,5], \quad<br />
(x_o, y_o) = (5,0), \quad<br />
\beta = 5<br />
</math><br />
<br />
As a result of [[isentropy]], the exact solution corresponds to a pure [[advection]]<br />
of the [[vortex]] at the [[free-stream velocity]]. Further details can be found in Yee et al. (1999).<br />
<br />
==References==<br />
<br />
*{{reference-paper | author=Yee, H-C., Sandham, N. and Djomehri, M., | year=1999 | title=Low dissipative high order shock-capturing methods using characteristic-based filters| rest=JCP, Vol. 150}}</div>Roberthealy1http://www.cfd-online.com/Wiki/2-D_laminar/turbulent_driven_square_cavity_flow2-D laminar/turbulent driven square cavity flow2007-08-13T18:37:14Z<p>Roberthealy1: /* References */</p>
<hr />
<div>== Introduction ==<br />
<br />
A classical [[test problem]] is [[numerical simulation]] of a [[laminar]]/[[turbulent]] flow of an [[incompressible viscous fluid]] in a square cavity with the upper moving [[boundary]]. It has long since been a "testing area" for approbation of [[approximation schemes]] for terms in initial equations as well as of [[computational models]] and methods. A large number of calculation data concerning this problem have been accumulated.{{Fact}} Therefore, it makes sense to return periodically to the solution of the problem verification and analysis of the [[computational codes]] developed. <br />
<br />
[[Image:Cavity2d.jpg]]<br />
<br />
== History ==<br />
<br />
The problem of a circulation flow in a cavity is of interest because of the relatively low level of [[computational resources]] required for its solution. In this case, the [[control volume]] is limited. Therefore, a small number of [[grid nodes]] are required and simple [[boundary conditions]] are set.{{fact} In the earliest renditions of this problem, the [[Navier–Stokes equations]] were transformed into [[vorticity–stream function]] variables for economy of [[computational resources]]. were obtained. The calculations were performed by brigades of specialists without the use of computers.{{fact}} <br />
<br />
When computers appeared, the indicated problem remained, as before, the focus of attention of specialists developing computational methods. A detailed analysis of methods concerning the problem considered that appeared in the period from the 1960s to the late 1980s is given in a set of monographs (for example 1, 2, 3). One of the first works in the area of numerical investigation of a viscous-fluid flow in a square cavity began thirty years ago [1] on a BESM-4 computer containing 21 × 21 grid nodes in one memory cube. At that time, in the mid-1970s, high-accuracy Arakava schemes of the second and fourth order of approximation and nonuniform grids were used for the first time for solving [[Navier–Stokes equations]]. <br />
<br />
One of the most important scientific achievements of the [[CFD]] in the 1980's was a numerical solution of the [[diffusion]] problem, since this problem is associated with errors in approximation of [[convective]] terms of equations. In simulation of [[separation flows]], a necessary condition for obtaining an exact result is the use of schemes with a [[low numerical viscosity]] (upwind schemes of the second and higher orders of approximation of the type of the [[Leonard scheme]] with [[quadratic interpolation]], the [[Agarval scheme]], and others) for representation of [[convective terms]] in [[transfer equations]].{{fact}} At the same time, it has been established that the first-order schemes give erroneous solutions at high [[Reynolds numbers]] even in the case where multi-grid methods are used.{{fact}} <br />
<br />
Progress in computational engineering and, especially, widespread use of personal computers in the 1980's and subsequent years have made it possible, first of all, to develop universal first-wave codes of applied programs, such as [[PHOENIX]], [[FLOW3D]], and [[FIDAP]], and then more modern information products / commercial [[CFD]] codes such as [[FLUENT]], [[StarCD]], and [[CFX]]. When computers with a large [[memory]] and a high [[CPU]] speed appeared, instead of the [[Navier–Stokes equations]] in [[transformed variables]], [[Navier–Stokes equations]] written in [[physical variables]] — Cartesian velocity or pressure components — began to be predominantly used.{{fact}} This made it possible to increase the number of computational cells (by an order of magnitude and more) and to increase the resolution in the near-wall region for this problem.<br />
<br />
<br />
== References == <br />
<br />
[1] Isaev S. A., Baranov P. A., Kudryavtsev N. A., Lysenko D. A., and Usachov A. E.<br />
SIMULATION OF A CIRCULATION LAMINAR FLOW AROUND A SQUARE CAVITY WITH A MOBILE BOUNDARY AT HIGH REYNOLDS NUMBERS WITH THE USE OF VP2/3 AND THE FLUENT PACKAGE. Journal of Engineering Physics and Thermophysics, Vol. 78, No. 4, 2005<br />
<br />
[2] Isaev S. A., Baranov P. A., Kudryavtsev N. A., Lysenko D. A., and Usachov A. E.<br />
Complex Analysis of turbulence models, algorithms, and grid structures at the computation of recirculating flow in a cavity by means of VP2/3 and FLUENT packages. Part 1. Scheme factors influence. Thermophysics and Aeromechanics, 2005, Vol: 12, No 4. <br />
<br />
[3] Isaev S. A., Baranov P. A., Kudryavtsev N. A., Lysenko D. A., and Usachov A. E.<br />
Complex Analysis of turbulence models, algorithms, and grid structures at the computation of recirculating flow in a cavity by means of VP2/3 and FLUENT packages. Part 2. Estimation of models adequacy. Thermophysics and Aeromechanics, 2006 , Vol 13, No 1.<br />
<br />
<br />
{{Stub}}</div>Roberthealy1http://www.cfd-online.com/Wiki/2-D_laminar/turbulent_driven_square_cavity_flow2-D laminar/turbulent driven square cavity flow2007-08-13T18:36:54Z<p>Roberthealy1: /* References */</p>
<hr />
<div>== Introduction ==<br />
<br />
A classical [[test problem]] is [[numerical simulation]] of a [[laminar]]/[[turbulent]] flow of an [[incompressible viscous fluid]] in a square cavity with the upper moving [[boundary]]. It has long since been a "testing area" for approbation of [[approximation schemes]] for terms in initial equations as well as of [[computational models]] and methods. A large number of calculation data concerning this problem have been accumulated.{{Fact}} Therefore, it makes sense to return periodically to the solution of the problem verification and analysis of the [[computational codes]] developed. <br />
<br />
[[Image:Cavity2d.jpg]]<br />
<br />
== History ==<br />
<br />
The problem of a circulation flow in a cavity is of interest because of the relatively low level of [[computational resources]] required for its solution. In this case, the [[control volume]] is limited. Therefore, a small number of [[grid nodes]] are required and simple [[boundary conditions]] are set.{{fact} In the earliest renditions of this problem, the [[Navier–Stokes equations]] were transformed into [[vorticity–stream function]] variables for economy of [[computational resources]]. were obtained. The calculations were performed by brigades of specialists without the use of computers.{{fact}} <br />
<br />
When computers appeared, the indicated problem remained, as before, the focus of attention of specialists developing computational methods. A detailed analysis of methods concerning the problem considered that appeared in the period from the 1960s to the late 1980s is given in a set of monographs (for example 1, 2, 3). One of the first works in the area of numerical investigation of a viscous-fluid flow in a square cavity began thirty years ago [1] on a BESM-4 computer containing 21 × 21 grid nodes in one memory cube. At that time, in the mid-1970s, high-accuracy Arakava schemes of the second and fourth order of approximation and nonuniform grids were used for the first time for solving [[Navier–Stokes equations]]. <br />
<br />
One of the most important scientific achievements of the [[CFD]] in the 1980's was a numerical solution of the [[diffusion]] problem, since this problem is associated with errors in approximation of [[convective]] terms of equations. In simulation of [[separation flows]], a necessary condition for obtaining an exact result is the use of schemes with a [[low numerical viscosity]] (upwind schemes of the second and higher orders of approximation of the type of the [[Leonard scheme]] with [[quadratic interpolation]], the [[Agarval scheme]], and others) for representation of [[convective terms]] in [[transfer equations]].{{fact}} At the same time, it has been established that the first-order schemes give erroneous solutions at high [[Reynolds numbers]] even in the case where multi-grid methods are used.{{fact}} <br />
<br />
Progress in computational engineering and, especially, widespread use of personal computers in the 1980's and subsequent years have made it possible, first of all, to develop universal first-wave codes of applied programs, such as [[PHOENIX]], [[FLOW3D]], and [[FIDAP]], and then more modern information products / commercial [[CFD]] codes such as [[FLUENT]], [[StarCD]], and [[CFX]]. When computers with a large [[memory]] and a high [[CPU]] speed appeared, instead of the [[Navier–Stokes equations]] in [[transformed variables]], [[Navier–Stokes equations]] written in [[physical variables]] — Cartesian velocity or pressure components — began to be predominantly used.{{fact}} This made it possible to increase the number of computational cells (by an order of magnitude and more) and to increase the resolution in the near-wall region for this problem.<br />
<br />
<br />
== Referemces == <br />
<br />
[1] Isaev S. A., Baranov P. A., Kudryavtsev N. A., Lysenko D. A., and Usachov A. E.<br />
SIMULATION OF A CIRCULATION LAMINAR FLOW AROUND A SQUARE CAVITY WITH A MOBILE BOUNDARY AT HIGH REYNOLDS NUMBERS WITH THE USE OF VP2/3 AND THE FLUENT PACKAGE. Journal of Engineering Physics and Thermophysics, Vol. 78, No. 4, 2005<br />
<br />
[2] Isaev S. A., Baranov P. A., Kudryavtsev N. A., Lysenko D. A., and Usachov A. E.<br />
Complex Analysis of turbulence models, algorithms, and grid structures at the computation of recirculating flow in a cavity by means of VP2/3 and FLUENT packages. Part 1. Scheme factors influence. Thermophysics and Aeromechanics, 2005, Vol: 12, No 4. <br />
<br />
[3] Isaev S. A., Baranov P. A., Kudryavtsev N. A., Lysenko D. A., and Usachov A. E.<br />
Complex Analysis of turbulence models, algorithms, and grid structures at the computation of recirculating flow in a cavity by means of VP2/3 and FLUENT packages. Part 2. Estimation of models adequacy. Thermophysics and Aeromechanics, 2006 , Vol 13, No 1.<br />
<br />
<br />
{{Stub}}</div>Roberthealy1http://www.cfd-online.com/Wiki/CFD-Wiki:Community_portalCFD-Wiki:Community portal2007-08-12T22:48:11Z<p>Roberthealy1: /* What needs to be done */</p>
<hr />
<div>This section is intended for people who work on adding content to the Wiki. So fellow CFD-Wikians, this is your page, private hideout, coffee room, coordination center, after-hours bar or whatever you want to use it for. If you still haven't contributed to the Wiki [[CFD-Wiki:Contribute something today|please do so today]]! We need your help and everyone is welcome to join our team of Wiki authors. <br />
<br />
==What's in the works==<br />
<br />
You who do significant additions to the Wiki, please add some information about your work, plans and progress here so that others can see what you are working on and perhaps help, monitor, come with suggestions and most importantly, be inspired by.<br />
<br />
* On May 21, 2007 we sent out a marketing email to all users of CFD Online. Hopefully this will make CFD-Wiki more well known and increase the number of additions --[[User:Jola|Jola]] 07:32, 21 May 2007 (MDT) <br />
<br />
* I am currently working on the [[Turbulence]] section with a new navigational structure and adding more text. --[[User:Jola|Jola]] 16:21, 17 June 2007 (MDT)<br />
<br />
== What needs to be done ==<br />
<br />
''Anything that you want!'' [http://en.wikipedia.org/wiki/Wikipedia:Be_bold Be bold] and just pick something that you feel that you can improve! If you need some help with good ideas on things to work on here are a few suggestions:<br />
<br />
* We have many turbulence models listed in the [[turbulence modeling]] section which still lack any description. Feel free to pick a model that you are familiar with and write a description of it. --[[User:Jola|Jola]] 01:50, 13 September 2005 (MDT)<br />
<br />
* The [[FAQ's | FAQ]] section is still very thin. If you are familiar with one of the larger CFD codes please consider adding a few questions and answers to the FAQ. --[[User:Jola|Jola]] 08:28, 13 September 2005 (MDT)<br />
<br />
* Editing! This is a constructive and collaborative work that improves with co-operation. -- [[User:Roberthealy1|Roberthealy1]] 16:48, 12 August 2007 (MDT)<br />
<br />
* If you are an experienced CFD engineer and an expert in a special application area you are very welcome to start a [[Best practise guidelines|best practise guideline]] for your speciality. --[[User:Jola|Jola]] 10:44, 18 September 2005 (MDT)<br />
<br />
* ''... add your suggestions on what should be done here''<br />
<br />
* As commercial CFD codes become more and more capable, CFD design agencies are more and more pressed to reconsider the cost vs. benefit of developing and maintaining in-house codes. I have had many conversations on this topic with other CFD managers and practitioners - there is a lot to think about: We should have a discussion forum on this topic.<br />
[http://www.example.com link title]<br />
<br />
==Other resources of interest==<br />
<br />
Here are a few links to pages that are of special interest for us CFD-Wikians:<br />
<br />
*[http://www.cfd-online.com/Forum/wiki.cgi Wiki Discussion Forum]<br />
*[[CFD-Wiki:FAQ| CFD-Wiki FAQ]]<br />
<br />
== CFD-Wikians - Who we are ==<br />
<br />
Add your name here if you make contributions to the wiki. <br />
<br />
The order is '''alphabetical (a - z)''' based on the '''user name'''.<br />
* [[User:Anand]] - www.iitm.ac.in<br />
* [[User:ABeevers]] - Adam Beevers<br />
* [[User:Aerodeepak]] - Deepak Thirumurthy<br />
* [[User:anurag]] - Anurag Sharma<br />
* [[User:bajjal]] - Bajjal Raghavendra<br />
* [[User:Ben]] - Ben D.<br />
* [[User:Discoganya]] - Sujit Kirpekar<br />
* [[User:ForMat]] - Matej Forman<br />
* [[User:ganesh]] - Ganesh N<br />
* [[User:harish]] - Harish Gopalan<br />
* [[User:jasond]] - Jason D.<br />
* [[User:jola]] - Jonas Larsson<br />
* [[User:kiranc]] - Kiran Chutkey<br />
* [[User:mirzapopovac]] - Mirza Popovac<br />
* [[User:Michail]] - Michail Kirichkov<br />
* [[User:Pavitran]] - Pavitran. D<br />
* [[User:praveen]] - Praveen. C<br />
* [[User:prokol]] - www.my-area.net<br />
* [[User:Roberthealy1]] - Robert Healy<br />
* [[User:Robkunz]] - Rob Kunz<br />
* [[User:s2vivek]] - vivekanandu.sakilam<br />
* [[User:sharonmshepard]] - Sharon Shepard<br />
* [[user:Sachinshendge]] - Sachin Shendge<br />
* [[User:Si]] - Simon Hubbard<br />
* [[User:snegan]] - Suriyanarayanan P<br />
* [[User:Suneesh]] - Suneesh S.S.<br />
* [[User:Toschi]] - Federico Toschi<br />
* [[User:Tsaad]] - [http://jedi.knows.it Tony Saad]<br />
* [[User:zxaar]] - Arjun Yadav</div>Roberthealy1http://www.cfd-online.com/Wiki/Template:FactTemplate:Fact2007-08-12T22:30:02Z<p>Roberthealy1: Need this page for index citations ~~~~</p>
<hr />
<div>{{fix<br />
|link=Wikipedia:Citing sources<br />
|text=citation needed<br />
|class=noprint Template-Fact<br />
|title=This claim needs references to reliable sources<br />
|date={{{date|}}}<br />
|cat=[[Category:All articles with unsourced statements]]<br />
|cat-date=Category:Articles with unsourced statements}}<noinclude><br />
{{template doc}}<br />
</noinclude></div>Roberthealy1http://www.cfd-online.com/Wiki/2-D_laminar/turbulent_driven_square_cavity_flow2-D laminar/turbulent driven square cavity flow2007-08-12T22:22:59Z<p>Roberthealy1: Requires further detail and addition. I have never read a treble split infinitive before.</p>
<hr />
<div>== Introduction ==<br />
<br />
A classical [[test problem]] is [[numerical simulation]] of a [[laminar]]/[[turbulent]] flow of an [[incompressible viscous fluid]] in a square cavity with the upper moving [[boundary]]. It has long since been a "testing area" for approbation of [[approximation schemes]] for terms in initial equations as well as of [[computational models]] and methods. A large number of calculation data concerning this problem have been accumulated.{{Fact}} Therefore, it makes sense to return periodically to the solution of the problem verification and analysis of the [[computational codes]] developed. <br />
<br />
[[Image:Cavity2d.jpg]]<br />
<br />
== History ==<br />
<br />
The problem of a circulation flow in a cavity is of interest because of the relatively low level of [[computational resources]] required for its solution. In this case, the [[control volume]] is limited. Therefore, a small number of [[grid nodes]] are required and simple [[boundary conditions]] are set.{{fact} In the earliest renditions of this problem, the [[Navier–Stokes equations]] were transformed into [[vorticity–stream function]] variables for economy of [[computational resources]]. were obtained. The calculations were performed by brigades of specialists without the use of computers.{{fact}} <br />
<br />
When computers appeared, the indicated problem remained, as before, the focus of attention of specialists developing computational methods. A detailed analysis of methods concerning the problem considered that appeared in the period from the 1960s to the late 1980s is given in a set of monographs (for example 1, 2, 3). One of the first works in the area of numerical investigation of a viscous-fluid flow in a square cavity began thirty years ago [1] on a BESM-4 computer containing 21 × 21 grid nodes in one memory cube. At that time, in the mid-1970s, high-accuracy Arakava schemes of the second and fourth order of approximation and nonuniform grids were used for the first time for solving [[Navier–Stokes equations]]. <br />
<br />
One of the most important scientific achievements of the [[CFD]] in the 1980's was a numerical solution of the [[diffusion]] problem, since this problem is associated with errors in approximation of [[convective]] terms of equations. In simulation of [[separation flows]], a necessary condition for obtaining an exact result is the use of schemes with a [[low numerical viscosity]] (upwind schemes of the second and higher orders of approximation of the type of the [[Leonard scheme]] with [[quadratic interpolation]], the [[Agarval scheme]], and others) for representation of [[convective terms]] in [[transfer equations]].{{fact}} At the same time, it has been established that the first-order schemes give erroneous solutions at high [[Reynolds numbers]] even in the case where multi-grid methods are used.{{fact}} <br />
<br />
Progress in computational engineering and, especially, widespread use of personal computers in the 1980's and subsequent years have made it possible, first of all, to develop universal first-wave codes of applied programs, such as [[PHOENIX]], [[FLOW3D]], and [[FIDAP]], and then more modern information products / commercial [[CFD]] codes such as [[FLUENT]], [[StarCD]], and [[CFX]]. When computers with a large [[memory]] and a high [[CPU]] speed appeared, instead of the [[Navier–Stokes equations]] in [[transformed variables]], [[Navier–Stokes equations]] written in [[physical variables]] — Cartesian velocity or pressure components — began to be predominantly used.{{fact}} This made it possible to increase the number of computational cells (by an order of magnitude and more) and to increase the resolution in the near-wall region for this problem.<br />
<br />
<br />
== Literature == <br />
<br />
[1] Isaev S. A., Baranov P. A., Kudryavtsev N. A., Lysenko D. A., and Usachov A. E.<br />
SIMULATION OF A CIRCULATION LAMINAR FLOW AROUND A SQUARE CAVITY WITH A MOBILE BOUNDARY AT HIGH REYNOLDS NUMBERS WITH THE USE OF VP2/3 AND THE FLUENT PACKAGE. Journal of Engineering Physics and Thermophysics, Vol. 78, No. 4, 2005<br />
<br />
[2] Isaev S. A., Baranov P. A., Kudryavtsev N. A., Lysenko D. A., and Usachov A. E.<br />
Complex Analysis of turbulence models, algorithms, and grid structures at the computation of recirculating flow in a cavity by means of VP2/3 and FLUENT packages. Part 1. Scheme factors influence. Thermophysics and Aeromechanics, 2005, Vol: 12, No 4. <br />
<br />
[3] Isaev S. A., Baranov P. A., Kudryavtsev N. A., Lysenko D. A., and Usachov A. E.<br />
Complex Analysis of turbulence models, algorithms, and grid structures at the computation of recirculating flow in a cavity by means of VP2/3 and FLUENT packages. Part 2. Estimation of models adequacy. Thermophysics and Aeromechanics, 2006 , Vol 13, No 1.<br />
<br />
<br />
{{Stub}}</div>Roberthealy1http://www.cfd-online.com/Wiki/CFD-Wiki:Community_portalCFD-Wiki:Community portal2007-08-08T22:28:09Z<p>Roberthealy1: /* CFD-Wikians - Who we are */</p>
<hr />
<div>This section is intended for people who work on adding content to the Wiki. So fellow CFD-Wikians, this is your page, private hideout, coffee room, coordination center, after-hours bar or whatever you want to use it for. If you still haven't contributed to the Wiki [[CFD-Wiki:Contribute something today|please do so today]]! We need your help and everyone is welcome to join our team of Wiki authors. <br />
<br />
==What's in the works==<br />
<br />
You who do significant additions to the Wiki, please add some information about your work, plans and progress here so that others can see what you are working on and perhaps help, monitor, come with suggestions and most importantly, be inspired by.<br />
<br />
* On May 21, 2007 we sent out a marketing email to all users of CFD Online. Hopefully this will make CFD-Wiki more well known and increase the number of additions --[[User:Jola|Jola]] 07:32, 21 May 2007 (MDT) <br />
<br />
* I am currently working on the [[Turbulence]] section with a new navigational structure and adding more text. --[[User:Jola|Jola]] 16:21, 17 June 2007 (MDT)<br />
<br />
== What needs to be done ==<br />
<br />
''Anything that you want!'' Be bold and just pick something that you feel that you can improve! If you need some help with good ideas on things to work on here are a few suggestions:<br />
<br />
* We have many turbulence models listed in the [[turbulence modeling]] section which still lack any description. Feel free to pick a model that you are familiar with and write a description of it. --[[User:Jola|Jola]] 01:50, 13 September 2005 (MDT)<br />
<br />
* The [[FAQ's | FAQ]] section is still very thin. If you are familiar with one of the larger CFD codes please consider adding a few questions and answers to the FAQ. --[[User:Jola|Jola]] 08:28, 13 September 2005 (MDT)<br />
<br />
* If you are an experienced CFD engineer and an expert in a special application area you are very welcome to start a [[Best practise guidelines|best practise guideline]] for your speciality. --[[User:Jola|Jola]] 10:44, 18 September 2005 (MDT)<br />
<br />
* ''... add your suggestions on what should be done here''<br />
<br />
* As commercial CFD codes become more and more capable, CFD design agencies are more and more pressed to reconsider the cost vs. benefit of developing and maintaing in house codes. I have had many conversations on this topic with other CFD managers and practitioners - there is a lot to think about: We should have a discussion forum on this topic.<br />
<br />
==Other resources of interest==<br />
<br />
Here are a few links to pages that are of special interest for us CFD-Wikians:<br />
<br />
*[http://www.cfd-online.com/Forum/wiki.cgi Wiki Discussion Forum]<br />
*[[CFD-Wiki:FAQ| CFD-Wiki FAQ]]<br />
<br />
== CFD-Wikians - Who we are ==<br />
<br />
Add your name here if you make contributions to the wiki. <br />
<br />
The order is '''alphabetical (a - z)''' based on the '''user name'''.<br />
* [[User:Anand]] - www.iitm.ac.in<br />
* [[User:ABeevers]] - Adam Beevers<br />
* [[User:Aerodeepak]] - Deepak Thirumurthy<br />
* [[User:anurag]] - Anurag Sharma<br />
* [[User:bajjal]] - Bajjal Raghavendra<br />
* [[User:Ben]] - Ben D.<br />
* [[User:Discoganya]] - Sujit Kirpekar<br />
* [[User:ForMat]] - Matej Forman<br />
* [[User:ganesh]] - Ganesh N<br />
* [[User:harish]] - Harish Gopalan<br />
* [[User:jasond]] - Jason D.<br />
* [[User:jola]] - Jonas Larsson<br />
* [[User:kiranc]] - Kiran Chutkey<br />
* [[User:mirzapopovac]] - Mirza Popovac<br />
* [[User:Michail]] - Michail Kirichkov<br />
* [[User:Pavitran]] - Pavitran. D<br />
* [[User:praveen]] - Praveen. C<br />
* [[User:prokol]] - www.my-area.net<br />
* [[User:Roberthealy1]] - Robert Healy<br />
* [[User:Robkunz]] - Rob Kunz<br />
* [[User:s2vivek]] - vivekanandu.sakilam<br />
* [[User:sharonmshepard]] - Sharon Shepard<br />
* [[user:Sachinshendge]] - Sachin Shendge<br />
* [[User:Si]] - Simon Hubbard<br />
* [[User:snegan]] - Suriyanarayanan P<br />
* [[User:Suneesh]] - Suneesh S.S.<br />
* [[User:Toschi]] - Federico Toschi<br />
* [[User:Tsaad]] - [http://jedi.knows.it Tony Saad]<br />
* [[User:zxaar]] - Arjun Yadav</div>Roberthealy1