Computational Investigation on the Thermal and Flow Characteristics of a Turbulent Dual Jet Impinging on a Heated Moving Surface

Abstract

The present investigation explores the dynamic effects of wall motion on the turbulent flow and thermal characteristics of a dual jet. The effects of variation in Reynolds number (Re) and offset ratio (OR) on different heat transfer and flow characteristics of turbulent dual jet have also been elucidated. The Reynolds number of flow and offset ratio are considered in the range Re=10000−25000 and OR=5−13, respectively. The wall to jet velocity ratio (Uw) is varied in the range of 0−2 at an interval of 0.5. The detailed study of heat transfer from moving impingement wall has been done by considering either the isoflux or the isothermal boundary condition on the heated wall. The motion of the wall strongly affects the thermal behavior and several flow characteristics of the dual jet. The nature of the velocity profile in the vector diagram changes from parabolic to linear in the far-field region due to the motion of the wall. The dual jet flow exhibits different patterns of self-similar profiles for different values of velocity ratio. The value of maximum longitudinal velocity (Umax) at a given axial position increases with the increase in impingement wall velocity. The exhaustive parametric study of dual jet flow over a moving wall reveals the fact that the process of heat transfer from heated moving wall to fluid is more intense for the higher value of Reynolds number and offset ratio, and for isoflux boundary condition. For the moving wall case, the maximum enhancement in heat transfer with reference to the stationary wall has been found to be 45.31%.