[poonkm]

I am simulating an AVA study which need to consider totally 8 prevailing wind directions. However, in the same model, with only changing the domain face and wind properties (velocity & direction), I found that 6 directions are converged but the remaining 2 are diverging (in fact, these 2 are in similar direction). Does anyone know what is happening? What I am thinking is that the mesh size, initial parameter are identical among these cases. I cannot explain why the cases are diverging. Could anyone help? Thanks a lot.

[Wikie]

Hello poonkm,

In such cases I always have a closer look at the residuals per cell and refine my cell size or change my geometry in critical areas. Sometimes the critical area is at the boarder where the air leaves the domain. In such cases the problem causing area is far away from my area of interest and I just neglect it.
To investigate your residuals per cell some inform programming is needed - but it's not tricky at all. Just add the follwing lines in your q1 (including the "stars"). Aftre your simulation is done you can visualize your residuals like any other variable in your preprocessing mode.

************************************************** **********
Echo save-block settings for Group 17
save17begin

(STORED of T1R is RESI(TEM1))
(STORED of U1R is RESI(U1))
(STORED of V1R is RESI(V1))
(STORED of W1R is RESI(W1))
(STORED of KER is RESI(KE))
(STORED of EPR is RESI(EP))
(STORED of P1R is RESI(P1))

save17end
************************************************** **********

'stored of' means to create a new variable. I named them T1R, U1R,.... You can name them as ever you want, but be aware not to use more then 3 characters. 'is RESI(variable)' applies the residual of your chosen variable to your new defined variable. I hope it's clear.

cheers
wikie