CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums

Search Results

Register Blogs Members List Search Today's Posts Mark Forums Read

Showing results 1 to 25 of 238
Search took 0.03 seconds.
Search: Posts Made By: praveen
Forum: Main CFD Forum July 24, 2014, 03:27
Replies: 6
Views: 140
Posted By praveen
You may not get the momentum to be constant but...

You may not get the momentum to be constant but the fluxes should be nearly constant. Can you check if the spike decreases with grid refinement. If it does then you dont need to worry about it.
Forum: Main CFD Forum July 23, 2014, 23:51
Replies: 6
Views: 140
Posted By praveen
Since you use a finite volume method total...

Since you use a finite volume method total momentum is conserved. Why do you say it is not conserved ?

In some cases, you can get exact solution with riemann solvers. Maybe you are in that...
Forum: Main CFD Forum July 23, 2014, 06:46
Replies: 6
Views: 140
Posted By praveen
We can write the Roe flux as F_{j+1/2} =...

We can write the Roe flux as


F_{j+1/2} = \frac{1}{2}[F(u_{j+1/2}^L) + F(u_{j+1/2}^R)] - \frac{1}{2}D(u_{j+1/2}^L, u_{j+1/2}^R) (u_{j+1/2}^R - u_{j+1/2}^L)


where the matrix D involves the...
Forum: Main CFD Forum May 19, 2014, 05:01
Replies: 9
Views: 334
Posted By praveen
It may happen that openfoam has some sort of...

It may happen that openfoam has some sort of asymmetry in the solution process which induces instabilities to develop. If it does not happen in comsol you have to add some disturbance yourself.
Forum: Main CFD Forum May 18, 2014, 13:49
Replies: 9
Views: 334
Posted By praveen
You may have to add some disturbance to induce...

You may have to add some disturbance to induce unsteadiness. E.g., perturb the initial condition by a small amount.
Forum: Main CFD Forum April 6, 2014, 12:00
Replies: 0
Views: 159
Posted By praveen
Some free codes: nsc2ke and codes from Blazek

I have put up two sets of cfd codes here which others might also find useful.

A 2d and axisymmetric fvm code on triangular grids
https://github.com/cpraveen/nsc2ke

Codes from the CFD book of...
Forum: Main CFD Forum March 17, 2014, 07:56
Replies: 3
Views: 214
Posted By praveen
There are several options for compressible codes ...

There are several options for compressible codes

Here are some simple codes which also have airfoil examples in them

NSC2KE (unstructured)
Blazek's CFD book comes with open source code...
Forum: Main CFD Forum March 16, 2014, 01:05
Replies: 6
Views: 631
Posted By praveen
I have c and fortran code for quasi-1d nozzle ...

I have c and fortran code for quasi-1d nozzle

https://code.google.com/p/cfdlab/source/browse/trunk/1d/nozzle/src-c
https://code.google.com/p/cfdlab/source/browse/trunk/1d/nozzle/src-f
Forum: Main CFD Forum January 12, 2014, 00:04
Replies: 3
Views: 1,510
Posted By praveen
The paper claims to prove existence of solution...

The paper claims to prove existence of solution under periodic boundary conditions. It does not mean that you have an analytical formula for the general solution. Still, if this turns out to be true,...
Forum: Main CFD Forum December 23, 2013, 09:32
Replies: 22
Views: 788
Posted By praveen
Going back to the original question about...

Going back to the original question about evaluating solution at some arbitrary point in the domain.

Galerkin, petrov-galerkin and DGFEM all give us a function as a solution, so in this case it is...
Forum: Main CFD Forum December 23, 2013, 05:16
Replies: 22
Views: 788
Posted By praveen
Suppose you have a weak formulation ...

Suppose you have a weak formulation


\mbox{Find } u \in V \mbox{ such that } a(u,v) = l(v) \mbox{ for all } v \in V


In the FEM, we approximation the function space V by a finite dimensional...
Forum: Main CFD Forum December 22, 2013, 03:17
Replies: 22
Views: 788
Posted By praveen
The FEM solution is a "function" which you can...

The FEM solution is a "function" which you can evaluate anywhere you like. You can also compute cell average from the FE solution.

FVM gives you only cell average value. To approximate the...
Forum: Main CFD Forum December 15, 2013, 00:15
Replies: 32
Views: 762
Posted By praveen
How do you compute divergence in physical space ?...

How do you compute divergence in physical space ? using finite differences will not be accurate. You have to take divergence of the spectral interpolation of the velocity field, which should then...
Forum: Main CFD Forum November 8, 2013, 06:39
Replies: 0
Views: 275
Posted By praveen
"Exact" solution of shu-osher test case

The Shu-Osher test case is one of the standard problems for compressible flows, see

http://flash.uchicago.edu/~jbgallag/2012/flash4_ug/node34.html#SECTION08117000000000000000

Most papers show...
Forum: Main CFD Forum November 1, 2013, 23:58
Replies: 8
Views: 297
Posted By praveen
In the limit of zero mach number, solutions of...

In the limit of zero mach number, solutions of compressible equations converge to solution of incompressible equations. This is not necessarily true for numerical solutions. For an excellent...
Forum: Main CFD Forum July 29, 2013, 10:06
Replies: 1
Views: 164
Posted By praveen
This is very good ...

This is very good

http://www-users.cs.umn.edu/~saad/IterMethBook_2ndEd.pdf
Forum: Main CFD Forum July 9, 2013, 21:13
Replies: 7
Views: 289
Posted By praveen
At sonic point one eigenvalue becomes zero. This...

At sonic point one eigenvalue becomes zero. This leads to loss of dissipation in one of the eigenfields. It manifests as an entropy violating jump inside a sonic rarefaction. Look for "entropy fix"...
Forum: Main CFD Forum June 17, 2013, 04:14
Replies: 4
Views: 287
Posted By praveen
I highly recommend this book ...

I highly recommend this book

http://www.cfd-online.com/Books/show_book.php?book_id=531

It gives a lot of physical insight.
Forum: SU2 April 9, 2013, 05:35
Replies: 1
Views: 348
Posted By praveen
Status of continuous RANS adjoint

Hello
Does version 2.0 have the continuous RANS adjoint with SA model ?

When I try a problem with FROZEN_VISC= YES, then the adjoint seems to run. But with FROZEN_VISC= NO, I get this error

...
Forum: Main CFD Forum March 20, 2013, 02:41
Replies: 26
Views: 798
Posted By praveen
div(u) = 0 is a constraint and it does not have...

div(u) = 0 is a constraint and it does not have any dynamics in it. The momentum equation is a convection-diffusion equation. So the convection brings in some wave type behavior.
Forum: SU2 March 12, 2013, 09:58
Replies: 20
Views: 1,277
Posted By praveen
I was making a serial run on the cgns file when...

I was making a serial run on the cgns file when the segmentation occurred. But yes, I can just use the converted file. Thanks.
Forum: SU2 March 12, 2013, 03:35
Replies: 20
Views: 1,277
Posted By praveen
Thanks for this. I tried it on my cgns grid. I am...

Thanks for this. I tried it on my cgns grid. I am able to save the mesh in su2 format but cannot run the cfd with the cgns mesh, some segmentation fault.

However I do not get segmentation fault if...
Forum: SU2 March 7, 2013, 03:41
Replies: 20
Views: 1,277
Posted By praveen
No. I am planning to write a separate converter...

No. I am planning to write a separate converter from cgns to su2 format but I have not had time to work on it.
Forum: SU2 February 20, 2013, 03:25
Replies: 20
Views: 1,277
Posted By praveen
Looking at cgnslib.h, I see that type 20 is MIXED...

Looking at cgnslib.h, I see that type 20 is MIXED


483 CGNS_ENUMV( MIXED ) =20,


and such type it does return npe=0


513 #define CG_NPE_MIXED 0
Forum: SU2 February 20, 2013, 02:54
Replies: 20
Views: 1,277
Posted By praveen
Thanks. I will try. I did notice some strange...

Thanks. I will try. I did notice some strange behaviour. We are finding number of nodes in the element here



/*--- Find the number of nodes required to represent
...
Showing results 1 to 25 of 238

 
Forum Jump

All times are GMT -4. The time now is 12:33.