Riblet Drag Reduction Modeling and Simulation

One of the most interesting passive drag reduction techniques is based on use riblets or streamwise grooved surfaces. Detailed flow features inside grooves can be numerically detected only by Direct Numerical Simulations (DNS), still unfeasible for high Reynolds numbers and complex flows. Many papers report DNS flows microgrooved surfaces providing fundamental details devices, but all are limited to plate channel far from engineering numbers. The numerical simulation other devices at very difficult perform due riblet dimensions (microns in aeronautical applications). To overcome these difficulties, some models have been developed recent years, data provided DNS, experiments, theoretical analyses. In models, modeled rather than effectively captured; however, analysis nonlocal effects practical configurations with riblets, requires their adoption. this paper, capabilities predicting riblets’ performance effect form shock waves shown. Two discussed compared showing respective advantages limitations possible enhancements. A comparison between two terms accuracy convergence discussed, new formulae proposed improve one models. Finally, a review results obtained configurations.