Dense gas effects on turbulent fluctuations of compressible turbulent shear layer*

Supercritical carbon dioxide (SCO2) is widely utilized in numerous current and developing engineering applications. Near the critical conditions, the dense-gas effects of thermodynamics and transport properties are prominent and need to be accounted for. As a canonical configuration, a set of compressible SCO2 planar shear layer flows are investigated using direct numerical simulations that incorporate the equation of state and transport model for real gasses. The growth of shear layers under various conditions across a range of convective Mach numbers and density ratios are studied. The dense-gas effects on flow structures are identified for each condition. The evolutions of turbulence statistics among different flow conditions are compared. The departure function value as the metric of the dense gas effects needs to be considered in addition to the convective Mach number, initial Reynolds number, and Atwood number to characterize the flow conditions used in ideal gas. By considering the departure function, the growth of turbulent density and temperature fluctuations at different freestream temperatures have shown an improved similarity behavior.