Jet impingement onto a cylindrical cavity Effect of jet velocity on heat transfer and skin friction

Purpose - The paper's aim is to provide information on heat transfer and flow characteristics for a jet emerging from a conical nozzle and impinging onto the cylindrical, which resembles the laser heating process, for researchers and graduate students working in the laser processing area, which can help them to improve the understanding of the laser machining process. Design/methodology/approach - A numerical scheme employing the control volume approach is introduced to model the flow and heating situations. The effect of jet velocity on the heat transfer rates and skin friction around the cylindrical cavity subjected to the jet impingement was investigated. Findings - Increasing jet velocity at nozzle exit enhances the heat transfer rates from the cavity wall and modifies the skin friction at cavity wall, which is more pronounced as the cavity depth increases to 1 mm. Research limitations/implications - The effects of nozzle cone angle on the flow structure and heat transfer characteristics were not examined, which perhaps limits the general usefulness of the findings. Practical implications - Very useful information are provided for the laser gas assisted processing, which has a practical importance in machining industry. Originality/value - This paper provides original information for the effects of the gas jet velocity on the cooling rates of the laser produced cavity.