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Shocktube help needed please

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Old   July 28, 2008, 12:34
Default Shocktube help needed please
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cfdguy08
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Hi

I had posted already about my doubt of not plotting. But it seems nobody has faced such problem.

I suppose, there might be something wrong in the way i tried to do the simulation of shocktube.can someone gimme more hint.?

here is the procedure i followed to setup shocktube... such as ...... made a duct of L/D=10, unsteady, 2d, implicit, energy enabled, 2nd order upwind pressure inlet=500 kPa and pressure outlet=125kPa, and also patching with the same two pressures in two different zones, having one interface as interior. Iterate with 1e-5 and performed 2000 iterations. Grid=25,000 in one meshfile and another meshfile with gird=548,904 cells. both meshfiles were attempted but no useful result.

The residual is plotted and it shows me a series of high frequency sinewave, besides, it says it is converged whenever it is on the bottomside-axis of sinewave.

Am I missing something. The result doesnot show shock-propagation and also it doesnot plot.

Please help.

thanks
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Old   July 28, 2008, 15:15
Default Re: Shocktube help needed please
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NRD
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Since the flow needs to be treated as compressible, just wanted to make sure if you switched to ideal gas law?
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Old   July 28, 2008, 22:41
Default Re: Shocktube help needed please
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cfdguy08
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yes sir, i did switch on the compressible by enabling ideal gas law.

Please gimme more details to resolve it..

I dont know where I am going wrong.

please help
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Old   July 29, 2008, 04:39
Default Re: Shocktube help needed please
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Tepin Joe
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Select Density Based Solver( Coupled Solver older version). Set density by ideal gas law. Rgds

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Old   October 4, 2010, 07:31
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How do we patch different Pressure values to two neighbouring fluid zones?

I guess I am trying to solve the very same problem. I want to see an unsteady shock wave and an expansion wave in my shock tube analysis but I need two fluid zones with distinct pressure values.

Edit: Well I found how to do so, sorry for that. It was under where we initialize the solution. I patched different pressure values for driver and driven zones. It seems like it is a tough question thou, I am not sure which turbulence model to use. First tried Spalart-Almaras since the main concept is about fast flowing fluids but it had dozens of problems (divergence, turbulence, pressure). I am giving a shot to inviscid flow.

Last edited by jackmarlowe; October 5, 2010 at 05:09. Reason: found my answer
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