A comparative study of turbulent stratified shear layers: effect of density gradient distribution

Abstract Direct numerical simulations are performed to compare the evolution of turbulent stratified shear layers with different density gradient profiles at a high Reynolds number. The include uniform stratification, two-layer hyperbolic tangent profile and composite these two profiles. All have same initial bulk Richardson number ( $$Ri_{b,0}$$ R i b , 0 ); however, minimum distribution across layer varied among cases. objective study is provide comparative analysis in term growth, kinetic energy as well mixing efficiency its parameterization. all cases shows development Kelvin–Helmholtz billows, transition turbulence by secondary instabilities followed decay turbulence. Comparison reveals that amount varies inside layer. do not correlate integrated TKE production, dissipation buoyancy flux. for fixed found be highest case lowest stratification. However, parameterizations flux coefficient based on ratio Ozmidov Ellison scales show similar scaling