Experimental investigation of heat transfer between hot air nozzle flow and cylinder

Heat Transfer and Fluid Flow Laboratory, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2 ; 616 69, Brno ; CZ
e-mail: zahradnik@lptap.fme.vutbr.cz, kotrbacek@fme.vutbr.cz

Abstract

A variety of experimental measurements were performed to clarify the influence of air pressure and distance from a nozzle outlet on the heat transfer intensity between a cylinder’s surface and the hot air flowing around the cylinder,which is placed in a rectangular air channel. The surface temperatures of five different surface pointsand air temperatures are recorded during each experiment. The heat transfer coefficient is calculated from the following recorded parameters: air temperature, calculated surface temperature, and heat flux. The surface temperature and the heat flux are obtained from finite element analyses using ANSYS. The boundary conditions for these analyses are taken from the temperature history records. Three different values of air pressures and distances are tested. The distribution of the heat transfer coefficient around the cylindrical surface is determined for these testing conditions.Results are presented in the form of graphs.