The direct measurement of engine power on an airplane in flight with a hub type dynamometer

Gove, W D Green, M W

This report describes tests made to obtain direct measurements of engine power in flight. Tests were made with a Bendemann hub dynamometer installed on a modified DH-4 Airplane, Liberty 12 Engine, to determine the suitability of this apparatus. This dynamometer unit, which was designed specially for use with a liberty 12 engine, is a special propeller hub in which is incorporated a system of pistons and cylinders interposed between the propeller and the engine crankshaft. The torque and thrust forces are balanced by fluid pressures, which are recorded by instruments in the cockpit. These tests have shown the suitability of this type of hub dynamometer for measurement of power in flight and for the determination of the torque and power coefficients of the propeller. (author)

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