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pankos August 1, 2011 11:47

Acoustic Pulse
 
I want to validate a Euler equations solver using the acoustic pulse as test case.
However, the exact solution of it, is complex to derived due to the appearence of integral which involves a bessel function.

What can i do for derive the exact solution? Any suggestions?

cfdnewbie August 2, 2011 03:23

would it have to be an acoustic pulse? you may start with sth simpler and build up from there to validate the code...e.g. the standard test case: pulse in rho..

panou August 2, 2011 05:30

Could you tell me more information for this case? Some papers which setup the test?

The convection of isentropic vortex is not good problem for validation?

andy_ August 2, 2011 07:46

Quote:

Originally Posted by pankos (Post 318340)
I want to validate a Euler equations solver using the acoustic pulse as test case.
However, the exact solution of it, is complex to derived due to the appearence of integral which involves a bessel function.

What can i do for derive the exact solution? Any suggestions?

Integrate the Bessel function using one of the many tricks you learnt at school and university? If your recall is a bit wonky then googling "integrate Bessel function" is likely to provide a whole bunch of options.

cfdnewbie August 2, 2011 12:23

Start by using a density pulse with a velocity field (should be convected along the streamlines).
If that works, use the method of the manufactured solution to create sth like a sinewave solution and test convergence with that - if you actually have access to the code and can add a source term, that is....

piljilaki August 5, 2011 14:19

wolfram alpha
 
just ask wolframalpha.com to integrate it for you.


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