Multi-objective optimization of a rotating cooling channel with staggered pin-fins for heat transfer augmentation

A rotating channel with staggered pin-fins is formulated numerically and optimized for performance (heat transfer/required pumping power) using a Kriging meta-model and hybrid multi-objective evolutionary algorithm. Two design variables related to cooling channel height, pin diameter, and spacing between the pins are selected for optimization, and two-objective functions related to the heat transfer and friction loss are employed. A design of experiment is performed, and 20 designs are generated by Latin hypercube sampling. The objective function values are evaluated using a Reynolds-averaged Navier-Stokes solver, and a Kriging model is constructed to obtain a Pareto-optimal front through a multi-objective evolutionary algorithm. Rotation in a cooling channel with staggered pin-fins induces Coriolis force that causes a heat transfer discrepancy between the trailing (pressure) and leading (suction) surfaces, with a higher Nusselt number on the trailing surface. The tradeoff between the two competing objective functions is determined, and the distribution of the Pareto-optimal solutions in the design space is discussed through k-means clustering. In the optimal designs, with a decrease in spacing between the pins, heat transfer is enhanced whereas friction loss is increased.