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Old   February 7, 2003, 04:14
Default About a test case of Woodward and Collela
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Praveen
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I need help with a test case of Woodward and Collela (JCP, 1988). This is the Mach 10 flow over a 30 degree wedge. In the actual implementation the coordinate frame is rotated by 30 degrees so that we can take a rectangular computational domain and the initial shock angle is 60 deg. I want to first verify whether I have got the initial conditions correct.

Pre shock (ahead of the shock) Density = 1.4 Pressure= 1.0 u = v = 0.0

Post shock (behind the shock) Density = 8.0 Pressure= 116.5 u = 8.25*cos(30) v = -8.25*sin(30)

At the top boundary the shock is cutting at 60 deg and we have to specify the exact solution on this boundary. The speed of the point at which the shock is cutting the top boundary is 10*cos(30) ?

With these conditions my computations are giving a mismatch between the shock speed that I specify on the top boundary and the speed obtained in the interior by the numerical scheme; the interior speed is larger than the speed specified at the top.
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Old   February 10, 2003, 09:49
Default Re: About a test case of Woodward and Collela
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aid
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Have you read Woodward and Collela----JCP, 1984---- I need help there!
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Old   February 11, 2003, 05:57
Default Re: About a test case of Woodward and Collela
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Praveen
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Well I myself need some help. Anyway what is your problem ?
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Old   February 11, 2003, 13:23
Default Re: About a test case of Woodward and Collela
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ptyue
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I think you've make some mistakes on the BC of upper boundary. At least, the intersection point of the shock and the upper boundary should move at the speed of 10/cos(30).
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Old   February 11, 2003, 14:19
Default Re: About a test case of Woodward and Collela
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gita
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Hi,

The top boundary condition is correct I guess. M_freestream=M_shock*cosec(60deg) which is the same as saying M_shock=10*cos(30). It's a very tough and challenging problem.

gita
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Old   February 11, 2003, 16:04
Default Re: About a test case of Woodward and Collela
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aid
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In their paper they said something like;

...to kinks in the shocks.

you can find this in many of the results they've reported. can you explain this to me mathematically please, may be numerically but you can do some tricks to treat this prblem. they looks like a Start-Up errors. i've read the paper many times but still i couldn't see the things 99.9%

so what do you think!
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