Large eddy simulation analysis of the heat transfer enhancement using self-oscillating fluidic oscillators

Abstract

Using an unsteady jet created by the fluidic oscillator represents many opportunities to enhance the heat removal performance of impinging jet. Numerical simulations were conducted to compare the heat transfer performance of two fluid oscillators and a direct jet with unsteady Reynolds-averaged Navier-Stokes (RANS) and large eddy simulation (LES) turbulence models implemented. Time-resolved and time-averaged flow fields and heat transfer results were presented. Simulation results showed that the fluid dynamic and heat transfer performance predicted by the RANS and LES models matched well for different Reynolds numbers.The self-oscillating impinging jets were beneficial in enhancing the heat removal performance by increasing the average Nusselt numbers and covering a larger impinging cooling surface. The wide impinging zone and significant heat transfer enhancement suggested it was promising to implement self-oscillating impinging jet concept into existing cooling technologies, such as multi-phase cooling and thin film cooling, for the next-generation high-performance heat exchangers.