@FlyingRaccoon could you please describe the effect of mach on CL vs AoA and
Cd in modern flight model? Compressibility should increase CL at low angle and
decrease stall aoa in the mean time. How can we tune this ? Thanks!
Hello @Gogosim Well I’m not qualified enough to give a proper answer on this
but I’ll add it to our FM questions review when I have some time with our core
simulation devs. Regards, Sylvain
@FlyingRaccoon Thank you Sylvain for not forgetting this kind of “detail”;
because, in the end, this detail which is not a detail makes all the
difference between a simple game and a real simulator…!
I second that demand. It would be awesome if we could tune the effect of
compressibility on CL and Cd.
Also, how are Cl and Cd affected near transonic speeds / M(crit) And, btw, how
is sweep back taken into consideration? Are there any adjustments to Cl based
on effective flow for swept-back wings? How is Cd calculated? Literature
suggests the Cosine rule to calculate the effective flow speed, or more
properly an adaptaion of this (square root) because of the difference between
infinit and finite wings, while drag should be based on the direct speed /
dynamic pressure.
Hi Folks,
I don’t understand why Mach effect on CL is still yet not implemented. You end with airliner cruising at M0.9 with nose 5 deg above horizon and it looks ridiculus.
I saw much effort was put into CL vs aoa curve changing shape in real time with flt controls deflection. Why not doing same with mach??
Mach or compressibility effect on CL are the following:
- it increases dCL/daoa slope
- it reduces in the mean time stall aoa.
Effect starts at M0.6 usually.
We could have a set of 3 parameters:
- mach threshold effect on cl
- slope inc factor
- stall aoa mach factor