A new mean-field theory of turbulent convection is developed by considering only the small-scale part of spectra as "turbulence" and the large-scale part, as a "mean flow," which includes both regular and semiorganized motions. The developed theory predicts the convective wind instability in a shear-free turbulent convection. This instability causes formation of large-scale semiorganized fluid ...

A method of deriving new relationships between near-surface turbulent fluxes and vertical differences of wind speed and potential temperature between two levels in the atmospheric surface layer from simplified second-order turbulence closure models is presented. The paper aims at a coherent treatment of fair-weather conditions and the asymptotic free convection limit. The traditionally used rep...

A method of deriving new relationships between near-surface turbulent fluxes and vertical differences of wind speed and potential temperature between two levels in the atmospheric surface layer from simplified second-order turbulence closure models is presented. The paper aims at a coherent treatment of fair-weather conditions and the asymptotic free convection limit. The traditionally used rep...

Two modelling approaches of transient heat transfer by free convection in a packed bed of spheres are carried out and then, compared with experimental results. The first approach uses computational fluid dynamics software which directly solves the NavierStokes equations and the local energy equations in the fluid and solid phases. It also includes radiation between the solid surfaces. The secon...

High-resolution simulations over a large tropical domain (;208S–208N, 428E–1808) using both explicit and parameterized convection are analyzed and compared to observations during a 10-day case study of an active Madden–Julian oscillation (MJO) event. The parameterized convection model simulations at both 40and 12-km grid spacing have a very weak MJO signal and little eastward propagation. A 4-k...

Thermal convection in the Antarctic and Greenland ice sheets has been dismissed on the grounds that radio-echo stratigraphy is undisturbed for long distances. However, the undisturbed stratigraphy lies, for the most part, above the density inversion in polar ice sheets and therefore does not disprove convection. An echo-free zone is widespread below the density inversion, yet nobody has cited t...

Thermocapillary Marangoni convection of liquid gallium was studied experimentally and numerically. A specially designed experimental setup ensured an oxide-free surface of the liquid gallium for a very long time. The convective flow at the free surface was found to be directed opposite to both buoyancy-driven and ordinary thermocapillary convection. The anomalous direction of the thermocapillar...

The objective of this work is to develop deep theoretical methods that are based on the solution of the integral boundary layer equations for investigating film cooling in liquid rocket engine. The integral model assumes that heat is transferred from hot free stream gas to the liquid film both by convection and radiation. The mass is transferred to the free srteam gas by the well-known blowing ...

in this paper, the effects of adding nanoparticles including tio2 to a fluid media for purpose of free convection heat transfer improvement were analyzed. the free convection was assumed to be in laminar flow regime and the solutions and calculations were all done by the integral method. water, as a newtonian fluid, was considered the base fluid (water) and all the thermo physical properties of...