What is AirFrictionMult exactly?

[xplane80]

What is AirFrictionMult exactly? Is it the Drag Co-efficiency?

[KarateBrot]

It does what it sais. It multiplies the air friction force by a factor. So for example if you have an airFrictionMult of 2.0 the air friction force of the object gets doubled.
I wrote a littlebit about air friction force here.

If you look at the formula for air friction force you can see what AirFrictionMult does:
-fv =
sim.airFrictionMultiplier * airFrictionMult * cross-section * ( sim.airFrictionLinear * v + sim.airFrictionQuadratic * v² )

[xplane80]

Thanks KarateBrot.

Then that mean terminal velocity of an object is wrong.

[KarateBrot]

Yeah but it's only wrong if your object isn't moving at 0°, 90°, 180° or 270°. So if something is in free fall it calculates it correctly.

[xplane80]

That's what I meant. So they need to fix this I think.

[KarateBrot]

Yes it would be very cool. Would make much things easier for me because I wouldn't have to correct the error for a project. The math for the correction is crazy. I even had to develop math functions for this because they're not available in algodoo