Development of an iterative PNS code for separated flows^parabolized Navier-Stokes

摘要

A new iterative parabolized Navier-Stokes (PNS) algorithm is being developed to efficiently compute supersonic viscous flowfields with embedded separated regions. ^In the vicinity of these embedded regions, the PNS equations are solved iteratively in order to duplicate the results that would be obtained with the complete Navier-Stokes equations. ^The algorithm splits the streamwise flux vector using either the Vigneron or the Steger-Warming methods. ^Once a separated flow region is computed, the algorithm returns to the usual PNS space-marching mode until the next embedded region is encountered. ^The algorithm has been successfully incorporated into NASA's upwind PNS code. ^The new algorithm has been validated by applying it to three separated flow test cases consisting of flow over a compression ramp, a shock impingement flow and flow over a cone-flare geometry. ^The present numerical results are in excellent agreement with other Navier-Stokes computations and experimental data. ^(Author)