A numerical investigation has been carried out applying single phase approach on turbulent forced convection flow of water based Al2O3 and TiO2 nanofluids flowing through a horizontal circular pipe under uniform heat flux boundary condition applied to the wall. The effect of volume concentrations, Brownian motion and size diameter of nanoparticles on flow and heat transfer have been examined fo...

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 effect of weak stratification on turbulent plane Couette flows is studied by means direct numerical simulations at the Prandtl number air. We demonstrate that tends to reduce intensity streamwise streaks in channel center, eventually breaking characteristic large-scale rolls. By analyzing bursting mechanism (i.e. sweeps and ejections) responsible for vertical momentum transfer, we observe w...

A Finite-Volume based POD-Galerkin reduced order modeling strategy for steady-state Reynolds averaged Navier–Stokes (RANS) simulation is extended low-Prandtl number flow. The model on a full which the effects of buoyancy flow and heat transfer are characterized by varying Richardson number. stresses computed with linear eddy viscosity model. single gradient diffusion hypothesis, together local ...

A model for the kinematic eddy viscosity has been developed which accounts for the turbulence produced as a result of jet interactions between adjacent streams as well as the turbulence initially present in the streams. In order to describe the turbulence contribution from jet interaction, the eddy viscosity suggested by Prandtl has been adopted, and a modification has been introduced to accoun...

Implicit variant WENO schemes with anti-diffusive flux for compressible flow computations are presented. These variant WENO schemes include the antis for the preconditioned compressible Euler/Navier-Stokes equations are also considered. The numerical flux of the variant WENO scdiffusive flux corrections, the mapped WENO scheme, and modified smoothness indicator. Implicit WENO schemeheme is cons...

We report on near-turbulent thermal convection of a nematic liquid crystal heated from below in a cylindrical cell with an aspect ratio (diameter/height) equal to 0.50 for Rayleigh numbers 2 × 107 . Ra . 3 × 108 and a Prandtl number of about 355. The Nusselt number Nu as a function of Ra did not differ significantly from that of an isotropic fluid. In a vertical magnetic field H , we found Nu(H...

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 results for the temperature profiles of turbulent Rayleigh-Bénard convection (RBC) in the interior of a cylindrical sample of aspect ratio Γ≡D/L=0.50 (D and L are the diameter and height, respectively). Both in the classical and in the ultimate state of RBC we find that the temperature varies as A×ln(z/L)+B, where z is the distance from the bottom or top plate. In the classical state,...