Optimization of a stepped circular pin-fin array to enhance heat transfer performance

A Stepped circular pin-fin array is formulated numerically and optimized with Kriging metamodeling technique to enhance heat transfer performance. The problem is defined by two non-dimensional geometric design variables composed of height of the channel, height of smaller diameter part of the pin-fins, and smaller diameter of the pin-fins, to maximize heat transfer rate compromising with friction loss. Ten designs generated by Latin hypercube sampling were evaluated by three-dimensional Reynolds-averaged Navier-Stokes solver and the evaluated objectives were used to construct the surrogate model. The predictions of objective function by Kriging model at optimum point show reasonable accuracy in comparison with the values calculated by RANS analysis. Optimum shape of pin-fins strongly depends on the weighting factor which measures importance of the friction loss term in the objective function. The thermal performances are much higher than that of the straight pin-fin at sampling optimum points with different weighting factors.