Optimization of bobsleigh bumper shape to reduce aerodynamic drag

The bobsleigh bumper shape was optimized to reduce aerodynamic drag using three-dimensional Reynolds-averaged Navier-Stokes analysis and surrogate modeling. The k-ω shear stress transport turbulence model was used as turbulence closure. The numerical results for the drag coefficient of the bobsleigh showed reasonable agreements with the experimental data. On the basis of the results of a parametric study using six parameters related to the shape of the front and rear bumpers, three parameters, i.e., the distances between the bumpers and the ground and the leading angle of the front bumper, were selected as design variables, and the drag coefficient was employed as an objective function for optimization. Latin hypercube sampling was used to select twenty-five design points in the design space. A surrogate model of the objective function was constructed using response surface approximation. The aerodynamic drag of the bobsleigh was reduced by 3.08% with the optimization compared with the reference design.