An adiabatic dry saturated steam compression process with inner evaporative spray cooling in screw compressors for steam heat pump systems is studied. Thermodynamic model and simulation of this variable-mass compression process are devised. Differential equations are formulated and used to calculate the amount of liquid injected and the work to drive the compressor on the basis of simplificatio...

The flow of gas in the suction chamber of an air brake compressor was analyzed, and losses due to pressure drop and heat transfer were identified by CFD simulations. Based on the results of the calculations the geometry of the suction chamber was modified to investigate possible improvements. Due to simple design modifications the flow direction of the gas was changed, which resulted in a reduc...

Extratropical tropospheric variability is investigated during Northern Hemisphere winter in the context of feedbacks between the meridional slope of the isentropic surfaces and the generation of eddy activity in the lower troposphere. The results reveal that at mid-high latitudes, periods of anomalously large tropospheric eddy heat fluxes (and thus wave generation) are preceded by anomalously s...

We analyze a quantum trajectory model given by a steady-state hydrodynamic system for quantum fluids with positive constant temperature in bounded domains for arbitrary large data. The momentum equation can be written as a dispersive thirdorder equation for the particle density where viscous effects are incorporated. The phenomena that admit positivity of the solutions are studied. The cases, o...

The authors examine feedbacks between the isentropic slope and the generation of eddy activity in the Northern Hemisphere winter. The results reveal that periods of enhanced lower tropospheric eddy heat fluxes (and thus wave generation) are preceded by anomalously steep isentropic surfaces in the free troposphere, and followed by anomalously poleward eddy momentum fluxes near the tropopause. Th...

On compactness of solutions to the compressible isentropic Navier-Stokes equations when the density is not square integrable Abstract. We show compactness of bounded sets of weak solutions to the isentropic compressible Navier-Stokes equations in three space dimensions under the hypothesis that the adiabatic constant γ > 3/2.

We examine the isentropic QCD equation of state within a quasiparticle model being adjusted to first principle QCD calculations of two quark flavours. In particular, we compare with Taylor expansion coefficients of energy and entropy densities and with the isentropic trajectories describing the hydrodynamical expansion of a heavy-ion collision fireball.

The mean meridional circulation of the atmosphere is presented using the mass (more specifically, the pressure corresponding to the mass) above the isentrope of interest as the vertical coordinate. In this vertical coordinate, themass-weightedmean circulation is exactly balanced by entropy sources and sinks with no eddy flux contribution as in the isentropic coordinate, and the coordinate can b...

In this paper, the statistical analyses are presented to study the thermal efficiency and power output of gas turbine (GT) power plants. For analyzing gas turbine operation and performance, a novel approach is developed utilizing the response surface methodology (RSM) which is based on the central composite design (CCD) method. An attempt is made to study the effect of some operational factors ...

The effect of a regenerative heat exchanger in a gas turbine is analyzed using a regenerative Brayton cycle model, where all fluid friction losses in the compressor is quantified by an isentropic efficiency term and all global irreversibilities in the heat exchanger are taken into account by means of an effective efficiency. This analysis, which generalizes that reported by Gordon and Huleihil ...