Effect of Offset Ratio and Plate Motion On Conjugate Heat Transfer in a Turbulent Offset Jet Flow Over the Heated Plate


 The present investigation focused on studying the conjugate heat transfer behavior for a turbulent offset jet flow over a heated plate moving uniformly in a positive axial direction. Heat transfer from heated walls to flowing fluids is a subject of great scientific interest due to many industrial applications like cooling hot rolling sheets and slabs, cooling continuous casting, etc. The conjugate technique is adopted in the present investigation as it requires consideration of both conductions in the solid and the convection from the solid surface to the fluid. A low-Re-modified k-e model developed by Yang and Shih (YS model) is adopted. The simulation involves a turbulent offset jet ejecting out of a nozzle at a Reynolds number of 15000 submerged into a stationary environment of Prandtl number 7. The plate at its bottom is heated by constant flux. The various parameters taken into account for observing the thermal behavior are offset ratios (OR=3,7,and 11), plate velocity ratios (Up=0-2), plate thickness ratios (S=0.5-1.5), and conductivity ratios (K=500- 2000). The interface temperatures and the Nusselt number suggest that better cooling can be achieved at lower offset ratio cases for low-velocity ratios. The contour diagrams, variation of average and local Nusselt number suggest the dominating effect of plate motion. A better cooling rate is achieved at a higher plate velocity, irrespective of the offset ratios.