Investigation of turbulent heat transfer in sinusoidal pulsating offset jets: a numerical study

Abstract

This research analyzes pulsating offset jets’ turbulent heat transfer properties at different oscillation frequencies and amplitudes. The complex turbulent flow patterns inside these jets create major effects on both flow dynamics and heat transfer performance. The analysis reveals that at low frequencies (20 Hz, 40 Hz), decreasing the oscillation amplitude generally leads to an improvement in overall heat transfer. At 80 Hz the heat transfer improves substantially when using smaller amplitudes instead of steady-state conditions. The flow fluctuations create major overall heat transfer variations which result in a maximum 15 % increase and a 35 % decrease compared to steady jets. The study demonstrates that a secondary Nusselt number peak develops after the first maximum on the surface due to complex turbulent flow interactions. The fluctuating flow patterns directly impact the reattachment point length which subsequently modifies heat transfer rates in the recirculation region. The results demonstrate how turbulence interacts with flow oscillation to impact heat transfer in offset jets