Optimization of a dimpled channel using a surrogate model

A numerical procedure to optimize the shape of a staggered dimpled surface to enhance the turbulent heat transfer in a rectangular channel is presented in this work. A Kriging model-based optimization technique is used with Reynolds-averaged Navier-Stokes analysis of the fluid flow and heat transfer with Shear Stress Transport turbulence model. The dimple depth-to-dimple print diameter ratio, channel height-to-dimple print diameter ratio, and dimple print diameter-to-pitch ratio are chosen as design variables. The objective function is defined as a linear combination of terms related to heat transfer and friction loss with a weighting factor. Latin Hypercube Sampling is used to determine the training points as a mean of the Design of Experiment. Through a sensitivity analysis, it was found that the objective function is most sensitive to the ratio of the dimple depth to dimple print diameter. Optimal values of the design variables were obtained in a range of the weighting factor.