Validation of the NPARC Code in Supersonic Base Flows

The supersonic annular ow over the base of a circular cylinder was used to validate the axisymmetric version of the NPARC code in a ow with large separated regions, attached ow regions, and free shear layers. Numerical results obtained using adaptive grids were compared to an extensive experimental database that includes turbulence information in the base region of the ow. The original NPARC code was modi ed to include a more faithful implementation of the original Baldwin-Lomax turbulence model. In addition, numerical results were obtained using a compressible version of the kmodel by Chien and a newly added kmodel by Grasso & Falconi. In general, the two-equation models predicted more accurately the overall features in the base ow than the zero-equation models, although all models had di culty predicting the base pressure. The results showed that the location of the reattachment point is strongly in uenced by the outer jet structure, which has typically been ignored in previous base-type ow investigations.