Circular air jet impingement cooling of a circular cylinder with flow confinement

摘要

Experimental and numerical investigations were carried out on cooling of a circular cylinder maintained at a constant heat flux by a circular air jet impingement with a semi-circular concave confinement at the bottom of the heated cylinder. In order to understand the effect of flow confinement on fluid flow and heat transfer characteristics, a parametric study was carried out for different radii of the flow confinement for different values of jet Reynolds number. Four different values of the nozzle to cylinder distance were considered. Experimental study was carried out to obtain the local Nusselt number distribution. Numerical study was used to obtain flow pattern and temperature distribution in the fluid domain. The results reveal that the flow confinement provided at the bottom of the cylinder improves the local Nusselt number by about 24% and average Nusselt number by about 17%. Numerical studies were also carried out with semi-circular flow confinement with an opening at the bottom. This configuration was found to result in maximum increase in local Nusselt number by 24% as compared to the results with confinement without an opening.