http://www.cfd-online.com/Forums/ Topics related to the software packages sold by Flow Science Inc. en Thu, 09 Sep 2010 09:11:57 GMT vBulletin 60 http://www.cfd-online.com/Forums/images/misc/rss.jpg http://www.cfd-online.com/Forums/ http://www.cfd-online.com/Forums/flow-3d/79836-two-phase-flows-turbulence-models.html Mon, 06 Sep 2010 09:28:21 GMT Hello, I am tring to model a two-phase flow which gas is turbulent and the liquid is laminar. However fluid tends to breakup instead of forming a... Hello,

I am tring to model a two-phase flow which gas is turbulent and the liquid is laminar. However fluid tends to breakup instead of forming a film when the turbulence model is activated.

Is there a way to activate turbulence for one of the fluids and not for the other?

Thanks for your help :) ]]> FLOW-3D Bcan http://www.cfd-online.com/Forums/flow-3d/79836-two-phase-flows-turbulence-models.html http://www.cfd-online.com/Forums/flow-3d/79834-fortran-compiler-customization.html Mon, 06 Sep 2010 08:54:03 GMT Hi All, as I understand it, I need the Intel Fortran Compiler 9.1 for customization (instead of the current Version 11). When I buy the current... Hi All,

as I understand it, I need the Intel Fortran Compiler 9.1 for customization (instead of the current Version 11). When I buy the current Version, I get an link to download the older version also.

But is there a possibility to get a test- 9.1- version? We are not yet sure if we need customization, so we wanted to test it before we spend a significant amount of money in it.

Best regrads,
Johannes ]]> FLOW-3D jk75 http://www.cfd-online.com/Forums/flow-3d/79834-fortran-compiler-customization.html http://www.cfd-online.com/Forums/flow-3d/79701-about-density.html Wed, 01 Sep 2010 01:54:20 GMT Fluids -> Density is 100, what does the text output that the macoscopic density in the free surface (air) and model . ...]]> if Model setup -> Fluids -> Density is 100,

what does the text output that the macoscopic density in the free

surface (air) and model .

Does it output 100?

Thanks everyone. ]]> FLOW-3D great1427 http://www.cfd-online.com/Forums/flow-3d/79701-about-density.html http://www.cfd-online.com/Forums/flow-3d/79595-solid-object-melting-flow-3d.html Fri, 27 Aug 2010 20:29:39 GMT I'm pretty new to Flow-3D and I'm trying to figure out a way to model the melting of a solid object.

As an example, I'd like to simulate a solid paraffin block on an angled hot plate, and model the block melting with the fluid running off.

It seems like Flow-3D only allows you to apply Solids material properties to components, not Fluids properties (which have all the phase change material properties).

Any suggestions on how to model this?

Thanks! ]]> FLOW-3D tgomm http://www.cfd-online.com/Forums/flow-3d/79595-solid-object-melting-flow-3d.html http://www.cfd-online.com/Forums/flow-3d/79419-pls-help-wave-runup-simulation.html Mon, 23 Aug 2010 15:45:02 GMT I am simulating a wave tank to study wave runup on GBS structures. I have a wave boundary and outflow on the other end. I haven't had any luck so far. The fluid volume keeps incresing, up to 20% within 200 sec, and so as water surface elevations. Is this normal? ]]> FLOW-3D Bo3D http://www.cfd-online.com/Forums/flow-3d/79419-pls-help-wave-runup-simulation.html http://www.cfd-online.com/Forums/flow-3d/79379-please-help-me.html Sun, 22 Aug 2010 17:12:27 GMT Hello everyone how can i mesh the non-uniform cylinerical fluid media like the below picture?(green region-feed container) Image:... Hello everyone


how can i mesh the non-uniform cylinerical fluid media like the below picture?(green region-feed container)

thank you in advance ]]> FLOW-3D s_saleh http://www.cfd-online.com/Forums/flow-3d/79379-please-help-me.html http://www.cfd-online.com/Forums/flow-3d/79303-wind-tunnel.html Thu, 19 Aug 2010 10:35:08 GMT Hi all, How to make a wind tunnel? i want to simulate a rotating blade.. please advise.. Thank you in advance for your help Hi all,

How to make a wind tunnel?
i want to simulate a rotating blade..

please advise..

Thank you in advance for your help ]]> FLOW-3D kaje http://www.cfd-online.com/Forums/flow-3d/79303-wind-tunnel.html http://www.cfd-online.com/Forums/flow-3d/79165-projection-method-3d.html Sun, 15 Aug 2010 01:37:45 GMT (u),r=>(v),teta=>(w). I used...]]> Hi

I want to simulation the flow in helical pipe.
I have one Continuity equation and three momentum equations in s=>(u),r=>(v),teta=>(w).
I used staggered mesh and descritized all of terms in central(finite difference).
I want to use projection method for solution these navier-stokes equations.

first problem:
What is stability condition for helical coordinates (three dimensional)in projection method?because I don’t know which number of interval in s,r,teta causes convergence!

second problem :
In descritized scheme we have i+2,i-2,j+2,j-2,k+2,k-2 indexes for u,v and w.
what do I have to do for the nodes of near the boundary? It means that two nodes produced out of domain but I don’t know value of them and they are unknowns.

Third problem:
We have to apply boundary conditions.in s and teta I have to apply periodic
Conditions.what are periodic boundary conditions for u,v and w in s and teta?

Is there any paper or books(references) for programming of projection method(three dimensional)?

Thanks for your guidance and aid ]]> FLOW-3D ehsan_am86 http://www.cfd-online.com/Forums/flow-3d/79165-projection-method-3d.html http://www.cfd-online.com/Forums/flow-3d/79159-paddle-wheel-simulation.html Sat, 14 Aug 2010 18:47:47 GMT Dear friends I want to model a rotating paddle wheel that intract with water in a free surface pond. how can I model the rotation of paddle? how... Dear friends
I want to model a rotating paddle wheel that intract with water in a free surface pond.
how can I model the rotation of paddle?
how can consider the boundary between water and air?
how can i mesh the non-uniform cylinerical fluid media?

thank you in advance ]]> FLOW-3D s_saleh http://www.cfd-online.com/Forums/flow-3d/79159-paddle-wheel-simulation.html http://www.cfd-online.com/Forums/flow-3d/79127-divergence-detected-amg-solver-x-momentum.html Fri, 13 Aug 2010 11:58:39 GMT Hello everyone,

I designed a blade for a turbine and now I'm trying to analyze it in 3D by FLUENT. As the blade is rotating I need to use moving reference frame for the fluid and set the blade as moving wall with the angular speed of 0 rad/s right ?. when I try to run the case I get this error: 'Divergence detected in AMG solver: x-momentum' . I checked my boundary conditions they seem ok and I reduced the relaxation factor for momentum but still I get the same error. could you please help me with, I don't know if the problem is because I'm not defining the boundary conditions correctly or there's something wrong with my mesh or for something else.

thank you, ]]> FLOW-3D arashm http://www.cfd-online.com/Forums/flow-3d/79127-divergence-detected-amg-solver-x-momentum.html http://www.cfd-online.com/Forums/flow-3d/79115-vawt-simulation.html Fri, 13 Aug 2010 03:44:49 GMT Hi all,

I'm just new with Flow 3D software.

I want to know the following

How can we simulate a Vertical Axis Wind Turbine in open air? for example we have a 7 m/s wind speed, Can we compute the rotation of the Blade of the Rotor? and also the Torque?

What is the proper set-up of its Mesh Geometry, Boundary Condition, Initial, Physic and all other paramters?

Thanks in advance for you help ]]> FLOW-3D kaje http://www.cfd-online.com/Forums/flow-3d/79115-vawt-simulation.html http://www.cfd-online.com/Forums/flow-3d/79091-restart-solidification-previous-solidifation-data-v9-4-a.html Thu, 12 Aug 2010 08:46:45 GMT Hi All,

I'm trying to restart a solidification calculation in F3D v9.4. When activating the button 'evaluate solidification data' I'm getting nonsense results for micro-porosity, whereas when activating the button 'restart with previous solidification data' I'm getting the error: "error extracting the variable sldtim". Is there a way to restart a calulation with the real solidification data in v9.4?

Regards,
Johannes ]]> FLOW-3D jk75 http://www.cfd-online.com/Forums/flow-3d/79091-restart-solidification-previous-solidifation-data-v9-4-a.html http://www.cfd-online.com/Forums/flow-3d/79047-shear-stress-calculation-flow.html Tue, 10 Aug 2010 20:34:01 GMT Dear Flow3d users, I have some question about the shear stress calculation in the closed channel flow. I have a rectangular channel section... Dear Flow3d users,

I have some question about the shear stress calculation in the closed channel flow.

I have a rectangular channel section and the water flows from left to right. I have used the periodic boundary conditions.

I want to know the shear stress on the walls. In the software itself I didn't find any option to extract the shear stress.

Is there any option to calculate shear stress, then would you good people please let me know ?

If there is not any option, then I think we have a equation of shear stress as follows:
Tou (shear stress) = neu * (du/dy)
neu= dynamic viscosity.

HOw do we use this equation with the output from Flow3d to calculate shear stress ?

Any help is highly appreciated. THank you. ]]> FLOW-3D auburnuser http://www.cfd-online.com/Forums/flow-3d/79047-shear-stress-calculation-flow.html http://www.cfd-online.com/Forums/flow-3d/79041-basic-question-geometry.html Tue, 10 Aug 2010 18:32:14 GMT This is a beginner's question - I have started to look at Flow3d recently. It appears that the software has limited options for creating geometry. I understand third party software are used for creating complex geometry.

At the moment, I am trying to simulate flow through a spillway. I am looking for recommendation as to what software/tool would be most suitable for the purpose.

Thanks in advance.

Cheers
NG ]]> FLOW-3D Aquatic http://www.cfd-online.com/Forums/flow-3d/79041-basic-question-geometry.html http://www.cfd-online.com/Forums/flow-3d/79027-2d-modelling-wall-effects.html Tue, 10 Aug 2010 11:45:28 GMT Dear all I want to know if I used a 2D modeling for my Free surface problem can I consider the effect of wall? this situation is theoretically... Dear all
I want to know if I used a 2D modeling for my Free surface problem can I consider the effect of wall? this situation is theoretically correct or not?

thanks ]]> FLOW-3D ati_ros61 http://www.cfd-online.com/Forums/flow-3d/79027-2d-modelling-wall-effects.html