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Instantaneous frictional torque of reciprocating combustion engines

Thesis/Dissertation ·
OSTI ID:6339012

A new method, (P-{omega}) method, for the determination of the Instantaneous Frictional Torque of reciprocating combustion engines, has been generalized through a process, named the IFT equation, for any mechanical system. The errors involved in the measurements of the cylinder pressure, P, and engine angular velocity, {omega}, have been examined. The analysis showed the pressure to be a function of the transducer type used for its measurement, and the angular velocity to be effected by the shaft encoder's accuracy ratio and the misalignment between crankshaft and encoder. The method has been applied to a single cylinder Diesel engine under different operating conditions. The mobility method has been used to model the frictional torque of the engine bearings. The experimental results along with the predictions of the bearing modeling showed, the frictional losses of the piston ring pack to be the major contributor to the engine's instantaneous frictional torque. Additionally they showed the instantaneous frictional torque during the compression-expansion strokes to be of the mixed lubrication type, and of the same type during the first cycle of the starting process. The first compression-expansion of the starting process showed exceedingly high frictional losses, the result of the very poor lubrication of the piston ring pack.

Research Organization:
Wayne State Univ., Detroit, MI (USA)
OSTI ID:
6339012
Country of Publication:
United States
Language:
English