CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

How to set up a diaphragm???

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

LinkBack Thread Tools Display Modes
Old   January 4, 1999, 20:05
Default How to set up a diaphragm???
Te-Wei Po
Posts: n/a
Hi! Dear all,

I have learnt CFD for two years, but I still have a limited knowledge of CFD. Because it is my first time to study CFD here.

I am trying to make a code to simulate the shock tube problem by using C language so far.

Now the problem that I face now is that how to set up the second diaphragm on the code.

So could you please help me and tell me the way to solve the problem???

Thank you very much!

  Reply With Quote

Old   January 9, 1999, 04:12
Default Re: How to set up a diaphragm???
Andrew Chernousov
Posts: n/a
I understood your question in such a way: to perform a 1-dimensional simulation of the shock-tube problem with a second diaphragm which is a local restriction, a model is needed to consider a wave interaction with this element.

So, you may try to treat this element as a special case of the border between 1D computational cells - a restriction of the "diaphragm" type, and solve the generalized Riemann problem to obtain computational fluxes (mass, momentum and energy) on the both sides of diaphragm on each time step.

This approach is rather straightforward to those familiar with Godunov-like methods. Generalized flux evaluation procedure must take into account characteristic properties of the governig equations, and certain hydraulic properties of the diaphragm as a local restriction. In other words, it is necessary to consider information brought by characteristics, and to fulfill the simple conditions of local quasi-steady flow through diaphragm itself.

The following conditions are commonly used: mass and enrergy conservation in steady flow, and a relation expressing hydraulic losses on diaphragm, for example a ratio of total pressures on each side (as a function of reference Mach number).

Goog luck!

  Reply With Quote

Old   January 11, 1999, 07:24
Default Re: How to set up a diaphragm???
Te-Wei Po
Posts: n/a
Hi! Dr./Mr. Chernousov,

Thank you very much for your reply. Your suggestion is very valuable for me! I will try this way which you suggest me. One more thing, may I ask you when I have any further question about this subject?

Anyway, thank you very much!

  Reply With Quote

Old   January 12, 1999, 17:36
Default Re: How to set up a diaphragm???
Andrew Chernousov
Posts: n/a
Mr. Po!

You may ask me any questions via this site or (carefully) by E-mail.

  Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
How to set a initial temperature and constant heat flux at same BC's?? Jane FLUENT 4 October 25, 2015 13:01
Compiling OpenFOAM13 on AMD64 with Redhat Enterprise mbeaudoin OpenFOAM Installation 20 June 17, 2008 06:43
Problem in installation of OpenFOAM sachin OpenFOAM Installation 7 January 22, 2008 02:40
Env variable not set gruber2 OpenFOAM Installation 5 December 30, 2005 05:27
how to setup a diaphragm RAN FLUENT 5 November 13, 2002 10:33

All times are GMT -4. The time now is 12:48.