Impingement heat transfer with pressure recovery

Abstract

A conventional impinging jet is effective at transferring a large heat flux. However a significant pressure loss is also experienced by the free jet of a jet impingement heat transfer device due to rapid expansion because it does not incorporate effective pressure recovery. A novel high-flux impingement heat transfer device, called the Tadpole, is developed to improve the heat transfer and pressure loss (performance) characteristics of the conventional impingement domain by incorporating pressure recovery with a diffuser. The Tadpole is scrutinized through an experimental comparison with a conventional jet impinging on the inner wall of a hemisphere under the turbulent flow regime. The Tadpole demonstrates promising capability by exceeding the performance characteristics of the impinging jet by up to 7.3% for the heat transfer coefficient while reducing the pressure loss by 13%. Multiple dimensional degrees of freedom in the Tadpole’s flow domain can be manipulated for an enhanced heat transfer coefficient, a reduced total pressure loss or a favourable combination of both metrics. A Computational Fluid Dynamics (CFD) model is developed, the Four-Equation Transition SST turbulence model demonstrates satisfactory experimental validation with a deviation of < 5% for the heat transfer coefficient and < 23% for the total pressure loss. The Tadpole is a promising heat transfer device for high-flux applications and is recommended for further work incorporating design improvements and multidimensional optimization.