Turbulent Heat Transfer Over a Moving Surface Due to Impinging Slot Jets

Abstract

In the present paper, turbulent heat transfer characteristics of submerged slot jets impinging on a moving surface at a constant temperature up to a Reynolds number of 50,000 have been studied. The turbulent flow field was resolved using the realizable k-ɛ model due to Shi et al. [1995, “A New k-ɛ Eddy-Viscosity Model for High Reynolds Number Turbulent Flows-Model Development and Validation,” Comput. Fluids, 24 , pp. 227–238] after rigorously establishing the adequacy of the model by comparison with large-eddy simulation data. A periodic element from a jet-bank configuration was chosen in the direction of the surface movement. The distribution of heat transfer on impinging surface is found to be significantly affected by the plate motion. However, the mean velocity distribution along vertical direction in the stagnation region is not affected by the plate motion. With increasing surface motion, the initial symmetric distribution changes to an inclined-S type pattern in the direction of the surface movement up to a certain level of surface velocity and the average heat transfer reduces. When the surface motion crosses this level, the net heat transfer starts increasing. The amount of heat transfer was found to be linked with the level of turbulent kinetic energy close to the impingement surface. The surface velocity at which the heat transfer reaches the value corresponding to the fixed surface value increases with increasing Reynolds number.