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Old October 17th 20, 03:29 PM posted to rec.aviation.soaring
Brian[_1_]
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Default Wheel brake effectiveness standards

IMO the aero dynamic forces are mostly not relevant to the brake sizing.
Since you should have a theoretical Drag number and be able calculate about how much drag your airframe and drag devices (flaps and spoilers) produce you could probably calculate a stopping distance with no brake. Probably need to add a small factor for wheel and bearing friction. And then decide how much more energy you want the brake to absorb.

But more realistically you want the brake to probably stop you in less than 500-1000 feet depending on the landing speed and weight of the aircraft. The Aerodyamic braking is going drop off of so fast that you can just consider it a design safety factor for the wheel brake system.

That leaves you with just the Kinetic energy of the aircraft at touch down being converted to the amount of the heat the brake can absorb. Again the stopping happens so fast you can pretty much assume none of the heat is going to be dissipated during the braking action. So how much heat does the brake need to be able to absorb?

The last consideration is the braking force that the brake can generate. Can it generate enough torque to put the glider up on its nose? You cann make some assumptions about how much elevator forces and resist and or assist this.

I am not an engineer but have done some design work an brakes for a couple different aircraft. So this information may be worth less than you paid for it.

Brian