Book Description

When the curvature of a ships surface is large and the stern boundary layer is thick the cross-stream inviscid velocity and pressure variation becomes important in stern boundary layer computations. Two viscous-inviscid interaction computation procedures are presented. One uses a marching technique in a natural streamline coordinate system together with the turbulence model to solve the axisymmetric Reynolds-averaged parabolized Navier-Stokes equations for the streamline velocity (u) flow angle curvature, and hence the pressure (p). The numerical procedure starts at a station on the body where the boundary layer is thin and marches downstream into the wake. The boundary conditions for the values of u and p over the inlet plane and along a cylindrical stream surface outside the boundary layer/wake are set by the appropriate values obtained from the other simple viscous-inviscid interaction computations using a modified thin boundary layer method and potential flow calculations about an equivalent displacement body. Comparisons of measured axial and radial velocity and pressure distributions and those computed by the simple interaction approximations and partially parabolized techniques have been made. The simple and efficient viscous-inviscid procedure for the computation of velocity and pressure variations across thick turbulent stern flows has been shown to be accurate enough to use as a preliminary design tool. Originator supplied keywords include: Thick turbulent stern flows, boundary layer; turbulence modeling; viscous-inviscid flow interaction; axisymmetric flows.