The Prandtl model succinctly combines the 1D stationary boundary-layer dynamics and thermodynamics of simple anabatic and katabatic flows over uniformly inclined surfaces. It assumes a balance between the along-the-slope buoyancy component and adiabatic warming/cooling, and the turbulent mixing of momentum and heat. In this study, energetics of the Prandtl model is addressed in terms of the tot...

Three ways in which near-boundary processes influence the ocean are reviewed. In the first topic, solutions for the flow and stratification in a situation where mixing dies away slowly away from a sloping boundary can show a sensitivity to the eddy Prandtl number, emphasizing the importance of studying the mixing of momentum as well as buoyancy. In the second topic, the importance of near-bound...

Abstract The ocean mixed layer model (OMLM) is improved using the large-eddy simulation (LES) and inverse estimation method. A comparison of OMLM (Noh model) LES results reveals that underestimation turbulent kinetic energy (TKE) flux in causes a negative bias depth (MLD) during convection, when wind stress weak or latitude high. It further found entrainment thickness underestimated. effects al...

Gas mixing in a T-shape micro mixer has been simulated using the Direct Simulation Monte Carlo (DSMC) method. It is considered that the adequate mixing occurs when the mass composition of the species, CO or N2, deviates below 1 % from their equilibrium composition. The mixing coefficient is defined as the ratio of the mixing length to the main channel’s height. As the inlet Kn increases, while ...

We aim to test the performances of an incompressible turbulence Reynolds-Averaged Navier–Stokes one-closure equation model in a boundary layer (NSTKE model). new condition for turbulent kinetic energy k (TKE), and we achieve mathematical analysis resulting NSTKE model. A series direct numerical simulation are performed, with flat non trivial topographies, obtain by interpolation generic formula...

Weakly nonlinear hexagon convection patterns coupled to mean flow are investigated within the framework of coupled Ginzburg-Landau equations. The equations are in particular relevant for non-Boussinesq Rayleigh-Bénard convection at low Prandtl numbers. The mean flow is found to (1) affect only one of the two longwave phase modes of the hexagons and (2) suppress the mixing between the two phase ...

We study the asymptotic expansion of solutions to the linearized compressible Navier-Stokes equations with highly oscillatory forces in the half-plane with nonslip boundary conditions for small viscosity. The wave length of oscillations is assumed to be proportional to the square root of the viscosity. By means of asymptotic analysis, we deduce that the zero-viscosity limit of solutions satisfi...

Despite its limitations, Prandtl’s mixing length model is widely applied in modelling turbulent free shear flows. extended addresses many of the shortfalls original model, but not so used, part due to additional mathematical complexities that arise derivation and implementation. Furthermore, both models, Prandtl neglects kinematic viscosity on basis it much smaller magnitude than viscosity. Rec...

gas mixing in a t-shape micro mixer has been simulated using the direct simulation monte carlo (dsmc) method. it is considered that the adequate mixing occurs when the mass composition of the species, co or n2, deviates below 1 % from their equilibrium composition. the mixing coefficient is defined as the ratio of the mixing length to the main channel’s height. as the inlet kn increases, while ...