SimScale CAE Forum

Forces Calculations

I’m doing an incompressible flow sim called “1 Moderate Incompressible (Average Wind Speed Crosswinds)”. I’m confused about some of the results that came from the forces calculations. https://www.simscale.com/workbench/?pid=1777385904090276987&mi=spec%3Ae30e51f9-5a5b-4972-a064-682d18e230b9%2Cservice%3ASIMULATION%2Cstrategy%3A6

So I set the sim to calculate the forces on the entirety of the upper and lower surface. Then, I did the same calculation but where the forces were calculated for each face on the body. When I compare the results, the “total surface force” is about equal to the force calculated on a single face. So I’m confused as my expectation was that the sum of the faces would add up to that of the total surface.

Thank you for your help

Hi @rafaelg,
could you in detail describe your doubts. I quickly checked the forces and they seem totally coherent.
For example for the lower part of the car we have:
Total lower force: Fx = 178.5N Fy = -308N
---------------------------------------------------------
Front wheels: Fx = 143.2 N Fy = -145.5N
Lower Floor: Fx = 0 N Fy = -108.8 N
Rear wheels: Fx = 36.2 N Fy = -52.3 N
---------------------------------------------------------
Total sum: Fx = 179.4 N Fy = -306.6 N (< 1% diff)

Best,
Richard

1 Like

@rszoeke Thanks for the clarification. I think I must’ve just been mixing up values when I was scrolling from surface to surface in the tests list.