The numerical modeling of jet impingement cooling onto a semicircular concave surface is reported. The performance of two-equation turbulence models (such as the k-epsilon model) is evaluated vs. the Reynolds stress model proposed. The Reynolds-averaged momentum and energy equations are solved together with. equations for the turbulence models, using a fully unstructured control volume method and a second-order high-resolution differencing scheme. Variations of jet Reynolds numbers of the spacing between the nozzle and the concave surface, as well as of the distance from the stagnation point in the circumferential direction, are considered. The predicted results are validated against experimental data. The developed approach yields low-cost and accurate predictions of processes where jet impingement cooling is involved. It can assist the design of relevant applications, with relative ease, especially in view of the enhanced heat transfer encountered in the concave surface jet impingement. (C) 2004 American Institute of Chemical Engineers.