Computation of Turbulent Flow Around Blade With Local Surface Roughness

To improve aerodynamic performance of a blade and to maintain its designed performance, many study have been focused on this point. The factors for aerodynamic performances of a blade are its geometry and operating conditions, which are almost fixed during its lifetime. On the other hand, the factor such as surface roughness generated by impure sand grain or oil droplet is variable one. The surface roughness on the blade affects the flow past it by its aerodynamic nature. The blade design can be improved by revealing this change in aerodynamic performance due to surface roughness. In this study, three-dimensional computations are carried out on the blade root with local surface roughness to investigate how the roughness will change the aerodynamic performance. The locality of the surface roughness distribution is simulated with particle tracks in three-dimensional flow. The model replacing the effect of roughness elements with virtual force is used to simulate turbulent flow around blade with local surface roughness.