A numerical study of nonlinear r-modes in isentropic, rapidly rotating relativistic stars, via 3-D general-relativistic hydrodynamical evolutions, is presented. On dynamical timescales, we find no evidence for strong coupling of r-modes to other modes at amplitudes of order one or larger. Therefore, unless nonlinear saturation sets in on longer timescales, the maximum r-mode amplitude is of ord...

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. ...

Isentropic processes in thermodynamics are fundamental to our understanding of numerous physical phenomena across different scientific and engineering fields. They provide a theoretical reference case for the evaluation real thermodynamic observations. Yet, as analytical relations isentropic transformations gas dynamics limited ideal gases, inability analytically describe non-ideal gases is sho...

We consider the Navier-Stokes equations for viscous compressible heat-conducting fluids with cylindrical symmetry. Our main purpose is to study the boundary layer effect and convergence rates as the shear viscosity μ goes to zero. We show that the boundary layer thickness and a convergence rate are of order O(μ) with 0 < α < 1/2 and O( √ μ) respectively, thus extending the result for isentropic...

In contrast to the experimentally widely used isentropic demagnetization process for cooling to ultra-low temperatures we examine a particular classical model system that does not cool, but rather heats up with isentropic demagnetization. This system consists of several magnetite particles in a colloidal suspension, and shows the uncommon behavior of disordering structurally while ordering magn...

This paper compares three popular notions of admissibility for weak solutions of the compressible isentropic Euler equations of gas dynamics: (i) the viscosity criterion, (ii) the entropy inequality (the thermodynamically admissible isentropic solutions), and (iii) the viscosity-capillarity criterion. An exact summation of the Chapman-Enskog expansion for Grad's moment system suggests that it i...

Densities ρ, Speeds of sound u, isentropic compressibilities κ s , intermolecular free lengths L f , specific acoustic impedances Z, relative association R a , intermolecular attraction α, excess molar volumes VE, excess isentropic compressibilities κ s E, excess intermolecular free lengths L f E and excess specific acoustic impedances ZE of acetophenone with ethyl cyanoacetate have been report...