Finding Velocity and Pressure Gradients

pandamaster9 · April 25, 2022, 13:49

Hello all,
I am fairly new to SU2 and CFD in general and I wanted to ask how to compute gradients for velocity and pressure respectively in SU2 Incompressible RANS.

Thank you.

bigfootedrockmidget · April 26, 2022, 03:39

Do you mean you would like to output and view the gradients? The gradients are not part of the output, so you have to compute them from velocity and pressure in e.g. paraview.

If you mean how we compute gradients for the discretization schemes, we do that with either Green-Gauss or weighted least squares:

Code:

% Numerical method for spatial gradients (GREEN_GAUSS, WEIGHTED_LEAST_SQUARES)
NUM_METHOD_GRAD= GREEN_GAUSS
%
% Numerical method for spatial gradients to be used for MUSCL reconstruction
% Options are (GREEN_GAUSS, WEIGHTED_LEAST_SQUARES, LEAST_SQUARES). Default value is
% NONE and the method specified in NUM_METHOD_GRAD is used.
NUM_METHOD_GRAD_RECON = LEAST_SQUARES

pandamaster9 · April 26, 2022, 05:42

Thank you for the response. I have used a work around using finite difference from the solution files to find the gradients

April 25, 2022, 13:49	Finding Velocity and Pressure Gradients	#1
pandamaster9 New Member Join Date: Apr 2022 Posts: 3 Rep Power: 4	Hello all, I am fairly new to SU2 and CFD in general and I wanted to ask how to compute gradients for velocity and pressure respectively in SU2 Incompressible RANS. Thank you.

April 26, 2022, 03:39		#2
bigfootedrockmidget Senior Member bigfoot Join Date: Dec 2011 Location: Netherlands Posts: 676 Rep Power: 21	Do you mean you would like to output and view the gradients? The gradients are not part of the output, so you have to compute them from velocity and pressure in e.g. paraview. If you mean how we compute gradients for the discretization schemes, we do that with either Green-Gauss or weighted least squares: Code: % Numerical method for spatial gradients (GREEN_GAUSS, WEIGHTED_LEAST_SQUARES) NUM_METHOD_GRAD= GREEN_GAUSS % % Numerical method for spatial gradients to be used for MUSCL reconstruction % Options are (GREEN_GAUSS, WEIGHTED_LEAST_SQUARES, LEAST_SQUARES). Default value is % NONE and the method specified in NUM_METHOD_GRAD is used. NUM_METHOD_GRAD_RECON = LEAST_SQUARES PENGGEGE777 and pandamaster9 like this.

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April 26, 2022, 05:42		#3
pandamaster9 New Member Join Date: Apr 2022 Posts: 3 Rep Power: 4	Thank you for the response. I have used a work around using finite difference from the solution files to find the gradients