STUDY OF THE LOCAL CONVECTIVE HEAT TRANSFER DOWNSTREAM A BACKWARD FACING STEP FOR VARIOUS UPSTREAM AIRFLOW CONDITIONS AND ENLARGEMENT FACTORS

摘要

This paper presents an analyse of the heat transfer coefficient downstream a backward facing step with various upstream airflow conditions: uniform flow outside a laminar boundary layer, uniform flow outside a turbulent boundary layer, and a fully developed flow. The local heat fluxes are obtained from temperature determination by infrared thermography on an assumed thermally thick wall used as boundary conditions of a numerical model. In this article we mainly focus on the maximum heat flux point position determined experimentally and numerically, and also on the influence of the expansion ration on the value of the maximum Nusselt number.