Investigation of turbulence production and dissipation due to isotropic and anisotropic roughness components on real surfaces

Roughness generally consists of structures that are either oriented anisotropic in directions tangential to the surface or isotropic, a superposition both components. Interactions between roughness elements exert significant influence on fluid mechanical losses. Cost-effective maintenance functionality surfaces aerodynamically relevant components such as blades requires quantitative prediction flow, which can be achieved through Reynolds-Averaged-Navier-Stokes Simulations (RANS). An established parameter used model flow is equivalent sand grain ks. By contrast, research presented here employs Direct Numerical (DNS) with Immersed Boundary Method (IBM) channel flows over anisotropic, and superimposed order investigate aerodynamic losses, for example, due turbulent production dissipation. The simulation results show does not correctly predict losses from surfaces, because reality, “angle attack” respect changes turbulence altered A non-linear relationship resistance this angle attack result local pressure gradients.