The evolution of cumulus clouds over a variety of radar-detected, boundary layer convergence features in eastern Colorado has been examined using Geostationary Operational Environmental Satellite (GOES) imagery and Weather Surveillance Radar-1988 Doppler (WSR-88D) data. While convective storms formed above horizontal rolls in the absence of any additional surface forcing, the most intense storm...

Regenerative cooling of aviation kerosene plays an important role for thermal protection of scramjet engines. Since the thermophysical properties of kerosene change acutely near the pseudo-critical point, heat convective in kerosene pipe flow is complicated. Here the convective heat transfer characteristics of China RP-3 aviation kerosene at a supercritical pressure are numerically studied usin...

We consider a class of fully self-gravitating accretion disks, for which efficient cooling mechanisms are assumed to maintain the disk close to the margin of Jeans instability. For such self-regulated disks the equations become very simple in the outer regions, where the angular momentum convective transport approximately balances the viscous transport. These latter equations are shown to lead ...

The use of small thermistors coated with absorbing material for the measurement of ultrasound fields is discussed. Equilibrium temperature rise gives a rough measure of intensity, but is affected by convective cooling due to streaming. The initial rate of temperature rise provides an accurate parameter for use in assessing energy density in all types of ultrasound field. Measurements made in st...

The heat transfer problem of a zero-mean oscillatory flow of a Maxwell fluid between infinite parallel plates with boundary conditions of the third kind is considered. The local and global time-averaged entropy production are computed, and the consequences of convective cooling of the plates are also assessed. It is found that the global entropy production is a minimum for certain suitable comb...

The entropy budget of an atmosphere in radiative–convective equilibrium is analyzed here. The differential heating of the atmosphere, resulting from surface heat fluxes and tropospheric radiative cooling, corresponds to a net entropy sink. In statistical equilibrium, this entropy sink is balanced by the entropy production due to various irreversible processes such as frictional dissipation, dif...

A hierarchy of hydrodynamical instabilities controlling the transfer of buoyancy through the oceanic mixed layer is reviewed. If a resting ocean of horizontally uniform stratification is subject to spatially uniform buoyancy loss at the sea surface, then gravitational instability ensues in which buoyancy is drawn from depth by upright convection. But if spatial inhomogeneities in the ambient st...

The cooling process is an important step during chocolate production. It influences final product quality characteristics such as gloss, texture and melting behavior. Furthermore, it a high energy consuming operation its optimization leads to increase in efficiency of the Dark was cooled pilot-scale tunnel with air temperatures Tair = 2, 12 18 °C mean velocities vin 1.5, 3.5, 6.0 m s−1. Convect...

A new measurement technique for the determination of the heat transfer coefficient and the film cooling effectiveness is presented. It is based on a regression of multiple transient liquid crystals experiments using an electrical heater-foil producing a nonhomogeneous surface heat flux. This is particularly interesting for film-cooled surfaces where each cooling hole in the heater-foil leads to...