Coefficient values are way too high

Hello dear community,

I am trying to design a proper rear wing for our formula student car. This is my latest model and I am happy with the downforce results. However, my force coefficients are always way too high. Can you tell me why?
When calculating the c_L via the max downforce, I get a value of 1,44 which seems too small.

https://www.simscale.com/workbench/?pid=8208520845167685040&rru=bb2ee0ec-8190-483f-bd6d-496939d98d9a&ci=936a49ce-207c-4e49-a4fe-ed29a9e481fe&ct=PLOT&mt=SIMULATION_RESULT

Hello HeWoelker,

thanks for reaching out to us here in the community.
I can see that you have already adjusted this, but please ensure to set up the Coefficient plot correctly for documentation purposes.

As you are doing a simulation at 19m/s please set the velocity to the reference velocity.

Based on my experience a CL of 1.44 is pretty reasonable for FS wings, but this cannot be said without proper validation.

Best regards
Sebastian

Hey Sebastian, thank you for your answer. Indeed, I did correct this, fingers are crossed. However, I am not sure about the reference area. Shouldn’t it be set by choosing the assigned faces? I did change the value from 1 to 0.94 (chord length times wing span) now, but don’t see a the reason behind it.

Hi HeWoelker,

usually the reference area is the frontal area, thus the area of the wing when projected to a frontal plane.

What you can also do is use the CLA. For this value, you always use 1 m² as the reference area. This ensures that when comparing two wing designs you compare the performance based on the force gained.

Best regards
Sebastian