Determination of Minimum Distance from a Cell Centroid to a Triangulated Surface: A Mesh Generation Implementation Technique

While using Spalart Allmaras turbulence model, wall-bounded flow approach should be followed to limit the resolution of the fine grids in the turbulent boundary layer. Spalart-Allmaras turbulence model is location dependent in contrast to algebraic models. There is no need to know the solution behavior in the direction normal to the solid wall so that it is far easier to implement on Cartesian grids. One overhead of Spalart-Allmaras model is the requirement of the minimum interval of each cell unit to the solid wall. In this study, the POINT2TRI3D algorithm is used which is based on Eberly’s suggestion where region conditions are explicitly defined. Simple calculation of the minimum displacement between a point p, and the triangle T(s,t) is the main goal of the algorithm by the use of a two-dimensional approach. During execution, these distances are stored for each cell before solution part of the codes. Initially, the programmer should search through the surface triangles and store the closest triangle to the centroid of computational cell in consideration. In the end, the closest distance is found and is returned as the input to the POINT2TRI3D subroutine.