Prediction of Hydrodynamic Forces and Moments for Underwater Vehicles Using Overset Grids

This paper describes the addition of an overset mesh capability to existing twoand three-dimensional Reynolds-averaged Navier-Stokes (RANS) solvers that share a cellcentered, finite volume, structured multiblock formulation. The calculation and processing of the overset interpolations are handled by leveraging third-party software. Specifically, the cell-centered, overset interpolation stencils for the two-dimensional and three-dimensional grids are generated using a structured, unstructured and generalized overset grid assembler (SUGGAR). Overset grid compatibility is then added to the RANS solvers by incorporating a library to handle the donor interpolation receptor transactions (DiRTlib). The software for integrating the hydrodynamic forces and moments on overlapping surface grids is new, so much of the paper is devoted to the description of that method. The approach that is described generates a unique surface using ranked polygons (USURP). Finally, surface pressures and the predicted forces and moments are shown to be in good agreement with measurements for DARPA SUBOFF and with more recent measurements for various configurations of the ONR Body-1 submarine model.