Refinement of Boundary-Layer Detection for Drag Decomposition of Computational Subsonic Flow Field

Abstract

A new boundary-layer sensor for drag decomposition of computational subsonic flow fields is introduced. Boundary-layer detection is the key technology for the drag decomposition method to compute profile drag precisely because it calculates the profile drag integrating the drag produced only in the boundary-layer. The new sensor is based on the boundary-layer thickness determination concept of the Baldwin-Lomax turbulence model. It is shown that the new sensor has advantages over the conventional boundary-layer sensor, such as dispensing with parametric studies and geometric extensions. Additionally, the new method showed less dependency on the computational grid size. This means that it may require less computational resources because it should be able to estimate the converged value of the profile drag using less computational grid. In this paper, the advantages of the new sensor are both visually and numerically inspected. The influence of approximating the order of the drag equation is also examined.