Space-time correlations or Eulerian two-point two-time correlations of fluctuating velocities are analytically and numerically investigated in turbulent shear flows. An elliptic model for the space-time correlations in the inertial range is developed from the similarity assumptions on the isocorrelation contours: they share a uniform preference direction and a constant aspect ratio. The similar...

Microgravity conditions offer an environment in which convection in a nonisothermal gas could be driven primarily by thermal stress. A direct examination of thermal stress flows would be invaluable in assessing the accuracy of the Burnett terms in the fluid stress tensor. We present a preliminary numerical investigation of the competing effects of thermal stress, thermal creep at the side walls...

Due to the very general nature of the Meshless Local Petrov-Galerkin (MLPG) method, it is very easy and natural to introduce the upwinding concept (even in multidimensional cases) in the MLPG method, in order to deal with convection-dominated flows. In this paper, several upwinding schemes are proposed, and applied to solve steady convectiondiffusion problems, in one and two dimensions. Even fo...

Results are presented from a series of analytical and numerical studies of buoyantly driven flows along heated vertical surfaces immersed in stably stratified fluids. Flows of the studied type are broadly represented in engineering and geophysical applications. First, the classical problem of one-dimensional natural convection flow along a heated wall is revisited for the case of a stably strat...

For thermal mixed-convection flows, the Nusselt number is a function of Reynolds number, Grashof number and the angle between the forcedand natural-convection directions. We consider flow over a heated cylinder for which there is no universal correlation that accurately predicts Nusselt number as a function of these parameters, especially in opposing-convection flows, where the natural convecti...

Recent numerical simulations of radiatively inefficient accretion flows onto compact objects have shown that convection is a general feature in such flows. Dissipation of rotational and gravitational energies in the accretion flows results in inward increase of entropy and development of efficient convective motions. Convectiondominated accretion flows (CDAFs) have a structure that is modified ...

Meridional flows with velocities of a few meters per second are observed in the uppermost regions of the solar convection zone. The amplitude and pattern of the flows deeper in the solar interior, in particular near the top of the radiative region, are of crucial importance to a wide range of solar magnetohydrodynamical processes. In this paper, we provide a systematic study of the penetration ...

By employing the equations of mean-square vorticity (enstrophy) fluctuations in strong shear flows, we demonstrate that unlike energy production of turbulent vorticity in non-rotating shear flows, the turbulent vorticity of weak convection in Keplerian disks cannot gain energy from vortex stretching/tilting by background shear unless the associated Reynolds stresses are negative. This is becaus...

this article deals with the study of the two-dimensional mixed convection magnetohydrodynamic (mhd) boundary layer of stagnation-point flow over a stretching vertical plate in porous medium filled with a nanofluid. the model used for the nanofluid incorporates the effects of brownian motion and thermophoresis in the presence of thermal radiation. the skin-friction coefficient, nusselt number an...