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Mismatch of mass flow rates after source term implementation in SU2

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Old   August 2, 2016, 12:33
Default Mismatch of mass flow rates after source term implementation in SU2
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Akshay Deshpande
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Hi SU2 users,

I have implemented a source term of dissipative heating in SU2 v. 4.2.0. The expression for the source term is S =  \frac{Q}{\pi^{3/2}.a.b.c} e^{(-((x-x_{o})/a)^{2} - ((y-y_{o})/b)^{2} - ((z-z_{o})/c)^{2})}
The total power deposited is Q = \iiint_{-\infty}^{\infty} Sdxdydz


To test the implementation, I am running a simple source in a 2D rectangular box case. The calculations are in dimensional form. The B.C's I am using are :
MARKER_SUPERSONIC_INLET at the inlet
MARKER_SUPERSONIC_OUTLET at the outlet
MARKER_FAR at the top and bottom edges
The location of the source is at (x_{o}, y_{o}) = (1.5, 0.5) , a = b = c = 0.1 and Q = 15 GW

I am getting the expected flow-field but the mass flow rates are not matching at the inlet and the outlet and therefore the energy balance is not working out. I have tried using both the Residual as well as Cauchy convergence criteria. For the later, I used CAUCHY_FUNC_FLOW as MASS_FLOW_RATE with maximum permissible CAUCHY_ELEMS corresponding to unsigned short datatype - but the result is still incorrect. I have also tried increasing the length of the domain.

Please let me know if there is any other way to run the calculation for a longer time to achieve convergence or if my implementation of the source term is incorrect.

I have attached the results below.



Thanks in advance!

Last edited by akshaydeshpande; August 2, 2016 at 20:56.
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Old   August 12, 2016, 11:08
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Akshay Deshpande
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I figured out the problem.
Apparently, my boundary conditions were incorrect. By changing to free-slip condition at the wall, the mass flow rates are exactly equal at the inlet and the outlet.
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