Author Topic: How to determine best speed for a given aircraft? (Read 209 times)

Elysian · « **on:** October 15, 2002, 06:05:20 PM »

Curious as to how one might be able to do this within the AH physics engine. Honestly, I barely even understand "corner velocity" beyond that I know it is an ideal speed to turn at. I do understand turn rate (degrees per second) vs. turn radius. I'm convinced, with my limited understanding of physics, that stall speed is going to play into this a lot (the minimum speed required to maintain 1g [against the force of gravity]).

Any way to test and figure this out?

capt. apathy · « **Reply #1 on:** October 15, 2002, 08:02:05 PM »

I may be wrong but I think stall speed is actually the speed required to maintain lift. not nescesarily a full G, just some lift. if you go below stall speed you have no lift at all.

Glasses · « **Reply #2 on:** October 15, 2002, 10:26:51 PM »

The air doesn't disappear it just becomes turbulent and starts to separate from the top of the wing as the airspeed drops, area of lo pressure which gives the lift of the wing, becomes higher in pressure thus you cannot maintain flight.(See Bernoulli's Principle.)

whgates3 · « **Reply #3 on:** October 15, 2002, 11:46:32 PM »

this web site http://www.aa.washington.edu/faculty/eberhardt/lift.htm
has a very good description - it's pretty long, but just hunt for "stall" on the page - confirms what Glasses said, but much more long winded - i would think you would get a stall also if the lift became less than the weight of the wing - one of the coolest planes ever concieved was specially designed for low stall speeds - the Ball-Bartoe Jetwing - a jet that could fly as slow as 25 knots w/out stalling (top speed ~350 knots)

dtango · « **Reply #4 on:** October 16, 2002, 12:57:41 PM »

Stall speed is the minimum airspeed required for an aircraft to maintain level-flight, where lift = weight. In other words it is the airspeed needed for the wings to generate enough lift to equal the weight of the aircraft.

Load Factor is defined as the lift / weight. In level flight lift=weight therefore load factor is defined as 1g in that condition. Things get trickier as you start talking about load factors in turns etc.

There is a way to calculate corner velocity for AH aircraft. It does involve knowing the stall speed of the a/c. Use the following equation. I'll spare everyone the aerodynamics since I can't explain it very simply.

Vcorner = Vstall * SQRT(6)

This is only good for a given flight parameter (weight, alt, and airframe config - e.g. no flaps etc.).

Tango, XO
412th FS Braunco Mustangs