Laminar Shear Layer Growth in Supersonic Underexpanded Flows

This paper offers an insight on the growth of laminar shear layer in supersonic jets and the extent of the compressible flow region (also known as inviscid core) that is bounded by the barrel shock and shear layer. Numerical simulations are performed on four nozzle shapes, obtained by different optimization methodologies, to probe the near-field area downstream of the nozzle exit. The results are linked to the trend of boundary layer growth within the nozzle and the nozzle wall shape. The viscous and inviscid areas in the near field are closely investigated to understand the factors that trigger the thickness of laminar shear layer and the boundaries of the inviscid core.