Jet impingement heat transfer characteristics of round surface geometries: A review

Jet impingement cooling over curved and round geometries plays a pivotal role in advanced thermal management systems ranging from gas turbines and electronics to solar energy and nuclear applications. Despite extensive research, existing studies remain fragmented, often restricted to isolated parameters such as jet spacing, Reynolds number, or surface curvature, leaving a lack of unified understanding across geometries, operating regimes, and enhancement techniques. This review systematically consolidates experimental, numerical, and empirical investigations covering concave, convex, cylindrical, spherical, and rotating surfaces, as well as modern advancements including mist-assisted cooling, rib-roughened targets, oblique jets, and microchannel integrations. Comparative analysis reveals how curvature ratio, jet inclination, inlet temperature, confinement, and nozzle geometry collectively influence stagnation-zone heat transfer, secondary peak formation, and thermal uniformity. Recent studies highlight the transformative potential of hybrid strategies—such as combining mist cooling with structured surfaces or optimizing multi-jet arrays via high-fidelity simulations—to achieve up to 200 % improvement in heat transfer performance. However, critical gaps persist in transient, multi-physics, and high-temperature applications, as well as in developing generalized correlations coupling flow, thermal, and geometric parameters. Addressing these gaps through integrated experiments, advanced turbulence modeling, and data-driven optimization frameworks offers a clear roadmap for next-generation cooling technologies.