An empirical frictional correction factor to the isentropic nozzle model has been developed for application to leakage modeling in scroll, rotary and other similar compressors. This correction factor is derived by calculating the leakage mass flow with a compressible, variable area, real gas properties model and then correlating the ratio of this flow to the isentropic nozzle model prediction. ...

A Brayton cycle with, external and internal irreversibilities, is analyzed. Optimization of the dimensionless work with respect to two parameters: the isentropic temperatures ratio and the allocation ratio of the heat exchangers, is performed. The qualitative and asymptotic behaviour of the coupled optimal analytic expressions obtained are presented. Using realistic numerical values of the isen...

The moist-air entropy can be used to analyze and better understand the general circulation of the atmosphere or convective motions. Isentropic analyses are commonly based on studies of different equivalent potential temperatures, all of which are assumed to fully represent the entropy of moist air. It is, however, possible to rely on statistical physics or the third law of thermodynamics when d...

In this paper, we investigate the characteristic structure of the full equations of magnetohydrodynamics (MHD) and show that it satisfies the hypotheses of a general variable-multiplicity stability framework introduced by Métivier and Zumbrun, thereby extending to the general case various results obtained by Métivier and Zumbrun for the isentropic equations of MHD.

Abstract Turbocharging plays a fundamental role not only in improving the performance of automotive engines, but also reducing fuel consumption and exhaust emissions spark-ignited biofuel, diesel, liquid, gaseous engines. Dedicated experimental investigations on turbochargers are therefore needed to evaluate better understanding its performance. The availability information steady flow turbocha...

the dependence of some thermodynamic properties of spin-polarized liquid 3he such as velocity of sound, adiabatic index, isentropic compressibility and temperature on the spin polarization has been investigated along different isentropic paths. the lennard-jones potential has been used in our calculations. it has been found that for higher values of entropy, the spin polarization has greater ef...

Ozone depletion above Kiruna (67.9N, 21.1E), Sweden, was investigated using daily ozone and temperature measurements by ozonesondes between 1 February and 25 March 1997. Using UKMO Ertel’s potential vorticity (EPV) and wind fields, three dynamically distinct regions were defined on a grid of isentropic surfaces viz.: the polar vortex boundary region characterized by steep EPV gradients, the are...

In this paper we study front tracking for a model of one dimensional, immiscible flow of several isentropic gases, each governed by a gammalaw. The model consists of the p-system with variable gamma representing the different gases. The main result is the convergence of a front tracking algorithm to a weak solution, thereby giving existence as well. This convergence holds for general initial da...