Flow Impingement onto a Conical Cavity at Elevated Wall Temperature: Effects of Conical Nozzle Cone Angle and Flow Velocities on Heat Transfer Rates

Conical nozzles are used for laser processing of engineering materials. The process parameters including the assisting gas jet velocity and the nozzle configuration influence the end product quality. The heat transfer rates and the skin friction in the laser-processed region depend on the flow structures developed in this region. In the present study, the flow structure around the conical cavity due to the jet is investigated numerically. The cavity wall temperatures are kept at 1500 K to resemble the laser-produced cavity. The effect of the jet velocity on the heat transfer rates from the cavity surface and the skin friction along the cavity wall are examined for two cone angles of the conical nozzle. The Reynolds stress turbulence model is accommodated to account for the turbulence while air is used as the working fluid in the simulations. It is found that the nozzle outer angle and the jet velocity alter the heat transfer rates from the cavity surface.