CRITICAL WORKING FREQUENCY OF RECIPROCATING HEAT-TRANSFER DEVICES IN AXIALLY RECIPROCATING MECHANISMS

The reciprocating heat-transfer device or reciprocating heat pipe has a high effective thermal conductance, and applications can be found in various reciprocating mechanisms, including offset cam mechanisms, Sc otch yoke mechanisms, and piston assemblies of internal combustion eng ines. The liquid return mechanism presents the most important operatin g limitation for this type of heal-transfer device. In this paper, the potential applications of the reciprocating heat-transfer device to V arious reciprocating mechanisms are described. Theoretical analyses ar e performed for the critical working frequency of the device in connec tion with the reciprocating mechanisms. An analytical solution and sem i-empirical correlation, with and without taking into account the how resistance, are obtained. Extensive experiments for the critical worki ng frequency are then undertaken on an engine tester. Comparison:of th e analytical and experimental results indicates that the analytical so lutions and semi-empirical correlation provide an accurate prediction for the working limits of reciprocating heat-transfer devices. (C) 199 7 Elsevier Science Ltd.