A mixed convection in a reciprocating Pi shape channel with opposite direction of gravity and inlet cooling fluids

Abstract

A numerical study is executed to investigate heat transfer mechanisms of a reciprocating channel cooled by fluids. The problem of the reciprocating piston is a moving boundary problem, and the Finite Element Method and arbitrary Largragian-Eulerian Kinematics method are then utilized. Due to the high temperature of the channel, a mixed convection is taken into consideration for simulating a more realistic situation. Directions of inlet cooling fluids and gravity are opposite. Concerning important parameters of the Reynolds number and Grashof number, reciprocating frequency and amplitude are examined. Thermal stratification layers which are found firmly on the top surface are deeply dependent on the magnitude of Gr/Re(2) ratio which directly affects the heat transfer mechanisms.