Multi-Element Unstructured Methodology for Analysis of Turbomachinery Systems

Abstract

In recent years unstructured mesh techniques have become popular for computational e uid dynamics analysis of external aerodynamic-type problems. The main advantages of such an approach include mesh generation over complex domains, grid adaptation in localized areas, and accuracy in efe ciently identifying complexities in local e ow physics. A hybrid unstructured methodology is used to carry out simulations for predominantly internal e ow turbomachinery applications. Issues related to skewness and other constraints of tetrahedral meshes are addressed in the context of turbomachinery-based propulsive e ows that exhibit a rich variety of length scales and timescales, as well asinteresting e ow physics. The unstructured framework permits the generation of a contiguous grid without internal boundaries between different components of a turbomachinery system and provides good local resolution in regions where the e ow physics becomes important. The increased numerical stability resulting from these factors coupled with the parallel solution framework yields an efe cient solution procedure for complex turbomachinery e ows. Numerical results are presented and compared against experimental measurements for a transonic diffuser‐ volute cone guration and a high Reynolds number pump.