Effect of single and multiple protrusions on thermal performance of slot jet impingement with curved surface

Abstract

The current study uses numerical methods to evaluate the thermal and flow characteristics of air jet impinging on concave surfaces with single and multiple protrusions on a surface. The impact of different operating parameters is also studied, including Reynolds number, jet inclination angle and nozzle-to-plate distance (H/B). No significant improvement in the overall thermal performance is noted with a single protrusion on the surface, although a higher heat transfer is observed in the stagnation zone. On the other side, the multiple protrusions on the surface have shown an increase or decrease in the overall thermal performance of jet impingement depending on protrusion diameter and height. The maximum improvement in the overall Nu is noted up to 19 % for the multi-protruded surface at H/B = 6 with orthogonal jet impingement. An oblique jet decreased the overall thermal performance compared to the orthogonal jet, regardless of the jet inclination angle. © 2023 Elsevier Ltd