[hamid1attar]

Hello,

I am new to SU2 and I want to run steady state simulations. I want to understand what the residuals mean in SU2, in my simulation I see Res[Rho] Res[RhoE] and I am not sure what these mean. At a particular residual evolution summary, it says log10[Maximum residual]: -3.94969.

The convergence parameters in my .cfg file are as follows, but I don't understand what these mean.

Could someone please explain what the minimum value of the residual means in SU2 and what Res[Rho] Res[RhoE] are?

Many Thanks!

% --------------------------- CONVERGENCE PARAMETERS --------------------------&
%
% Convergence criteria (CAUCHY, RESIDUAL)
CONV_CRITERIA= RESIDUAL
%
% Residual reduction (order of magnitude with respect to the initial value)
RESIDUAL_REDUCTION= 10
%
% Min value of the residual (log10 of the residual)
RESIDUAL_MINVAL= -12
%
% Start convergence criteria at iteration number
STARTCONV_ITER= 25
%
% Number of elements to apply the criteria
CAUCHY_ELEMS= 100
%
% Epsilon to control the series convergence
CAUCHY_EPS= 1E-10
%
% Function to apply the criteria (LIFT, DRAG, NEARFIELD_PRESS, SENS_GEOMETRY,
% SENS_MACH, DELTA_LIFT, DELTA_DRAG)
CAUCHY_FUNC_FLOW= DRAG

[ralviani]

They mean the residuals of your Conservative variables:


Rho
RhoU
RhoE


The residual values are essentially the solution change of these variables through your iterations.


There's loads of information online about this, I suggest you do some research on the matter.