The thermodynamics of inflationary expansion can be either isentropic or non-isentropic. Representing the early universe by a two fluid mixture of radiation energy density ρr and vacuum energy density ρv, the inflationary regime, when the scale factor accelerates R̈ > 0, is for ρv > ρr. From the point of view of two fluid Friedmann cosmology, isentropic inflationary expansion appears as a limiti...

Previous studies have demonstrated the key role of baroclinicity and thus the isentropic slope in determining the climatological-mean distribution of the tropospheric eddy fluxes of heat. Here the authors examine the role of variability in the isentropic slope in driving variations in the tropospheric eddy fluxes of heat about their long-term mean during Northern Hemisphere winter. On month-to-...

We present or recall several equilibrium methods that allow one to compute isentropic processes, either during the compression or the release of the material. These methods are applied to compute the isentropic release of a shocked monoatomic liquid at high pressure and temperature. Moreover, equilibrium results of isentropic release are compared to the direct nonequilibrium simulation of the s...

Tropospheric transport can be described qualitatively by the slow mean diabatic circulation and rapid isentropic mixing, yet a quantitative understanding of the transport circulation is complicated, as nearly half of the isentropic surfaces in the troposphere frequently intersect the ground. A theoretical framework for the effective isentropic diffusivity of tropospheric transport is presented....

Based on reanalysis data for the years 1980–2001 from the European Centre for Medium-Range Weather Forecasts (ERA-40 data), a climatology of tropospheric zonal-mean water vapor fields and fluxes in isentropic coordinates is presented. In the extratropical free troposphere, eddy fluxes dominate the meridional flux of specific humidity along isentropes. At all levels, isentropic eddy fluxes trans...

To improve the performance of electrically assisted turbochargers (EATs), influences hub profile and casing on EAT were numerically studied by controlling upper lower endwall profiles. An artificial neural network a genetic algorithm used to optimize profile, considering total pressure ratio isentropic efficiency at peak point. Different performances prototype optimized under variable clearance...

Starting from a standard description of an ideal, isentropic fluid, we derive the effective theory governing a gapless non-relativistic mode—the sound mode. The theory, which is dictated by the requirement of Galilei invariance, entails the entire set of hydrodynamic equations. The gaplessness of the sound mode is explained by identifying it as the Goldstone mode associated with the spontaneous...

Large-scale chaotic stirring stretches tracer contours into filaments containing fine spatial scales until smallscale diffusive processes dissipate tracer variance. Quantification of tracer transport in such circumstances is possible through the use of Nakamura’s ‘‘effective diffusivity’’ diagnostics, which make clear the controlling role of stirring, rather than small-scale dissipation, in lar...

The isentropic system of equations has particular advantages in the numerical modeling of weather and climate. These include the elimination of the vertical velocity in adiabatic flow, which simplifies the motion to a two-dimensional problem and greatly reduces the numerical errors associated with vertical advection. The mechanism for the vertical transfer of horizontal momentum is simply the p...

Organic fluids could be classified into wet, dry and isentropic types according to the slope of the saturated vapor envelope on a temperature-entropy diagram. Due to the limited availability of pure isentropic refrigerants, attempts are made to make isentropic mixtures by mixing wet and dry refrigerants with an appropriate composition in the present work. A simple principle for selecting potent...