Direct numerical simulations of the time evolution of homogeneous stably stratified shear flows have been performed for mean flow Richardson numbers in the range from 0.075 to 1.00 and for Prandtl numbers ranging from 0.1 to 2. The local or instantaneous results indicate that when the turbulent Froude number FrT = 1 the peak value of mixing efficiency is Rf ≈ 0.25, a result independent of the P...

The peristaltic flow of a Prandtl fluid in an asymmetric channel has been investigated both analytically and numerically. This is the first article describing feature of Prandtl fluid model in peristaltic literature. The governing equations for the proposed Prandtl fluid model are derived in Cartesian coordinates system. Asymmetric channel have been taken into account for the present analysis. ...

a = mean speed of sound, R T 1=2 aw = mean speed of sound at the wall, RTw 1=2 C = turbulent viscosity parameter, T= Lk cp = specific heat at constant pressure, R= 1 ; 1004:5 J= kg K cv = specific heat at constant volume, R= 1 ; 717:5 J= kg K f = uniform body force, w=h h = half channel height hw = wall length scale, h=Re i = turbulence intensity, 2k=3 = U1 k = turbulent kinetic energy, uiui=2 ...

We are concerned with the chaotic flow fields of turbulent mixing. Chaotic flow is found in an extreme form in multiply shocked Richtmyer-Meshkov unstable flows. The goal of a converged simulation for this problem is to obtain converged solutions for such micro solution features as the joint probability distributions of the temperature and species concentration, as well as the macro features su...

We report direct numerical simulations (DNS) of stratified plane Couette (SPC) flows in both continuous and layered stratifications for a wide range of Prandtl number Pr from 0.7, 7 to 70. In the continuously stratified set-up, Pr has a significant impact on the momentum and heat fluxes across the flow. Variations of these fluxes then modifies the turbulence characteristics in the way that is c...