Effect of high free stream turbulence on heat transfer between plates and air flows: A review of existing experimental results

Abstract

This article reviews the research carried out to characterise the effect of free stream turbulence on heat transfer coefficients at the surface of a plate. In spite of the contradictions which appear at first glance, it seems that the transfer coefficient increases according to the free stream turbulence level either in the laminar boundary layer or in the turbulent boundary layer. The transfer coefficient increases regularly from turbulence level of 5% to 10% obtained with grid-type generators to the higher values of between 20% and 60% generated from jets. However describing the phenomenon using the sole effect of turbulence level leads to a large disparity of experimental results. Analysing the evolution of velocity and near wall temperature profiles under the influence of an increasing free stream turbulence leads to an interpretation which would make it possible to understand the nature of the phenomenon and explain the disparity of experimental results.