Three dimensional Reynolds-averaged Navier-Stokes flow solver development and its application to an S-shaped subsonic diffuser analysis

A three dimensional Reynolds-averaged Navier-Stokes C code implementing the Cebeci-Smith turbulence model for compressible turbulent flow was developed and applied to an S-shaped subsonic diffuser flow field analysis. Two diffuser shapes were considered corresponding to a NASA design and an optimized shape. Message Passing Interface (MPI) parallel computation software was integrated in the code to enable parallel computation. 3-D general coordinate transformations were introduced inside the code that enable the code to predict complex three dimensional flow fields. An algebraic turbulence model (Cebeci-Smith turbulence model) was selected and integrated into the code to predict turbulent flow. Finally, the code was applied to the S shape baseline diffuser computation for verification. The flow analysis represented by the static pressure coefficient, total pressure indices, static pressure, velocity, density distributions inside the duct agree well with experimental and previous investigations' data. This verifies that the code can be fully functional. Afterwards, this code was utilized to conduct an optimized S shape subsonic diffuser flow analysis. The flowfield depicted by flow contour plot and cross-section velocity vector plots are very similar to previous investigations' results, but quantitative analysis shows that there are some deviations. This may be due to the different turbulence models implemented.