Semi-local scaling and turbulence modulation in variable property turbulent channel flows

摘要: We theoretically and numerically investigate the effect of temperature dependent density viscosity on turbulence in channel flows. First, a mathematical framework is developed to support validity semi-local scaling as proposed based heuristic arguments by Huang, Coleman, Bradshaw [“Compressible turbulent flows: DNS results modelling,” J. Fluid Mech. 305, 185–218 (1995)]. Second, direct numerical simulations (DNS) flows with different constitutive relations for are performed assess validate statistics. The database obtained solving low-Mach number approximation Navier-Stokes equation. Finally, we quantify modulation due changes fluid properties. In simulations, internally heated at both walls fixed, such that friction Reynolds wall quantities Re ? = 395 all cases investigated. show case variable ?, but constant Re???(?¯¯¯/?w)???????/(?¯¯¯/?w)Re? (where bar subscript w, denote averaging averaged quantity, respectively), across whole height, statistics exhibit quasi-similarity property For where Re???Re? channel, found maintained similar Re?? distributions, even if their individual mean profiles substantially differ. With decrease towards center ( Re??