Selection for wall calculator in wind tunnel

[alu0101125336]

Im quite unsure im selecting right the things in the dialog tab of the wall calculator, what i usally do is to hide the fluid volume and then selet the volume selection type, after that i select the whole study model,but my concern comes when i show the fluid volume and repeat the process obtaining the same results.

So when i realized that i just go and make everything equal again but this time i choose the volume selection and click on the fluid volume to unselect it. Doing so i get very different results than from doing it with the surface selection type. As conclusion i know is such a easy task but im completly lost . I've also attached the cfz. file if needed

Sorry for disturbing for such a thing and i hope you are all good, thank you   

[marwan_azzam]

Hello,

I'm not really sure what the issue is.

I was able to select surfaces on your model for the Wall calculator as seen in image below.

Are you not able to select a certain surface?

Marwan

[alu0101125336]

I can select everything, but the problem comes when getting the right ressults. I dont know which volumes i have to select in order to get the drag force and lift force. Because if i select the car body via volumes the forces are differents to when i select the same surfaces via surface selection. 

I know is a bit confusing explantion sorry

[marwan_azzam]

When you select the car body via volumes as you state, do you individually select all 83 volumes that make up the car?

[alu0101125336]

i select all with double check and then deselect the fluid volume

[marwan_azzam]

I would create a selection group for all the volumes representing the car then in the calculator select that group.

Marwan

[alu0101125336]

And how i create a selection group ?

[alu0101125336]

i've already created it thank you