We consider the motion of a compressible viscous fluid in the asymptotic regime of low Mach and high Reynolds numbers under strong stratification imposed by a conservative external force. Assuming a bi-dimensional character of the flow, we identify the limit system represented by the so-called lake equation the Euler system supplemented by an anelastic type constraint imposed by the limit densi...

A generalized form of Reynolds equation for fluid lubrication has been derived considering the effects of viscosity variation in the film and slip at the bearing surfaces. Various specific cases have been deduced and the concept of multiple-layer lubrication introduced. The higher lubricant viscosity near the bearing surface is beneficial in reducing the coefficient of friction but the effect o...

Abstract   Due to restrictions on the choice of relaxation time in single relaxation time (SRT) models, simulation of flows is generally limited base on this method. In this paper, the SRT lattice Boltzmann equation was used to simulate lid driven cavity flow at different Reynolds numbers (100-5000) and three aspect ratios, K=1, 1.5 and 4. The point which is vital in convergence of this scheme ...

It is shown that, for stationary isotropic turbulence, Taylor’s well known dissipation surrogate Du/L can be derived directly from the Karman-Howarth equation and is in fact a surrogate for inertial transfer, which becomes equal to the dissipation, as the Reynolds number tends to infinity. The expression found for the dissipation rate ε is ε = A3u ′3 L [

A stochastic representation of the dynamics of the Burger's turbulence model and of the two{dimensional turbulence is developed. The random velocity eld is regarded as a multivariate stochastic Markov process deened by a master equation. It is shown that Burgers' equation and the two{dimensional Navier{Stokes equation are obtained as the macroscopic equations for the averages of the underlying ...

Fe3O4 nanofluid fully developed forced convection inside a copper tube is empirically investigated under the effect of a magnetic field. All of the investigations are performed under laminar flow regime (670≤Re≤1700) and thermal boundary conditions of the tube with uniform thermal flux. The tube is under the effect of a magnetic field in certain points. This research aims to study the effect of...

A rationale for the empirically observed Strouhal-Reynolds number relation for vortex shedding in the wake of a cylinder is provided. This rationale derives from a mechanism of vortex formation observed in numerical simulations of two-dimensional vortex shedding coupled with an order of magnitude estimate of the terms in the vorticity transport equation based on this mechanism.

We report on recent progress towards the development of a 3D optimization capability for transonic ow at high Reynolds numbers. In this paper we demonstrate optimization based on the 3D laminar Navier-Stokes equation, and we present validation of the ow analysis scheme based on the 2D Navier-Stokes equations with turbulence modelling.

Paper the Jeffery-Hamel flow-a nonlinear equation of 3rd order-is studied by homotopy perturbation method. After introducing homotopy perturbation method and the way of obtaining Adomian’s polynomial, we solved the problem for divergent and convergent channel. Finally, velocity distribution and shear stress constant is depicted at various Reynolds numbers and comparing our results with some ear...