Heat Transfer of Impinging Jet and Ribbed-Duct Flows with System Reciprocation

摘要

This paper describes an experimental investigation of heat transfer for impinging jet and ribbed duct flows under system reciprocation which focuses on the variable reciprocating effects on these two flow systems for piston cooling application. The experimental data reconfirmed the unsteadi- ness of reciprocating flow which led to the local temporal heat transfer variations when both test sections reciprocated. For impinging jet flow, reciprocation did not modify the fundamental physics that facilitated heat transfer but the local instantaneous heat transfer could be improved or impeded by reciprocation, depending on the Reynolds number and reciprocating frequency.