NUMERICAL SIMULATION OF HEAT TRANSFER IN TWO TURBULENT PLANE JETS IMPINGING ON A FLAT PLATE

摘要

This study presents the numerical predictions of the fluid flow and heat transfer characteristics for impingement of two turbulent jets on a solid heated plate. The study is relevant to a wide range of practical applications including forced convection, manufacturing, material processing and electronic cooling, drying paper, textiles and tempering of glass. The turbulent governing equations are solved by a control volume- based finite-difference method with power-law scheme, the well known k-ε model, and its associate wall function to describe the turbulent behaviour. The velocity and pressure terms of momentum equations are solved by the SIMPLE (Semi-Implicit Method for Pressure-Linked Equation) method. In this study non uniform staggered grids are managed. The power law interpolation scheme (PLDS) is used to achieve the best accuracy. The possibility of improving the heat transfer is carried out according to the characteristic parameters of the interaction jet-wall. The parameters interesting include jet exit Reynolds number (Re), dimensionless nozzle to surface space (D/W), the separating distance between the two jets and the difference of the temperature between the jet exit and the wall. For a fixed nozzle-plate distance, the influence of the Reynolds number on the heat transfer is investigated. Good agreement with previous studies of single jet and multijet is observed. Different type of interaction occur, when the wall is located before, within and after the merging region, The influence of the nozzle-plate distance and the Reynolds number on the Nusselt number is also discussed.