![]() ![]() I started with a proportion of skin friction to total drag (Cf / total Cd) of 31% and I have raised it to 71%.įrom the theory, I know that a streamlined 3D object (like a submarine hull) should have a very high skin friction drag component, but I don’t really have a solid value to aim for because there is no way to measure the experimental value of the skin friction drag. Reducing the size of the mesh at the wall boundary and reducing the size of the boundary layer mesh increases the value of the skin friction component and also causes the pressure drag to reduce. ![]() I am also trying to stick to the good practises of meshing, like using y+ values close to 1, with the purpose to achieve more accurate calculation of the shear stresses on the walls. I am performing mesh sensitivity studies, to refine its resolution and distribution. ![]() I am finding that my simulation results tend to underestimate the viscous component (frictional drag) and overestimate the pressure component of drag. I am trying to validate the turbulence models and mesh with known published data on airship or submarine design (you can see the design of the rotationally symmetrical objects I am using in the. I am performing 3D external flow simulations at high Reynolds numbers (10^6 - 10^8) using RANS turbulence models such as SST.
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