Hey modder folks! A question that I can't find documented anywhere, and would be really helpful for some Aero improvements to Automation. We need to know what effect the angle of a wing has on the drag it produces, the size of the surface and the dragCoef are all easy enough to work out, but we can't find any documented info on the impact of AoA. For example, our wings in the system we're working on are currently at 26deg from horizontal, so how much less drag does that have compared to one that's just a completely vertical plate facing into the wind? Best info I can find is https://www.beamng.com/threads/lift-and-drag-forces-analysed.36171/ , but that seems to be taking 0 to mean "Facing flat into the wind" and only goes to 45deg off vertical, so not far enough to get to the angle we need. It also seems to be reasonably inconsistent with speed, and is quite an old thread, so all in all unsure of the validity of that data? Appreciate any input ya'll have, as it'll help us put much more accurate drag/downforce/lift exports into the next Automation patch
Not sure if the official documentation will help, but maybe: https://documentation.beamng.com/modding/vehicle/sections/triangles/ They don't have any numbers here but just vague descriptions and some parameters though. The aero system was also updated quite recently (along with the tire system) but nowhere does it say what exactly changed in it and probably there's some new stuff to it that only the devs know. You could always make the angle adjustable with variables, so that the players can tune it to whatever they like. Or make it dependant on the angle that you choose in Automation when making the car.
The base drag is a function of a triangle's frontal area following the drag equation: https://en.wikipedia.org/wiki/Drag_equation For lift, there are two cases: First case is the most common and happens when lift and drag coefficients are around the same: Total force (sum of drag and lift) magnitude looks like the normal drag equation: Ftotal = 1/2 * DragCoef * pmass * v^2 * triangle_frontal_area [*] The direction of Ftotal will be colinear to the normal of the triangle In the case where lift and drag are not similar, then Fdrag (projection of Ftotal to velocity direction) will behave similarly to above case, but Flift decouples and will follow an airfoil like curve depending on the ratio between the lift and drag coefficients. [*] triangle_frontal_area = area of triangle projected to a plane perpendicular to flow
