We study several schemes of rst or second-order accuracy based on kinetic approximations to solve pressureless and isothermal gas dynamics equations. The pressureless gas system is weakly hyperbolic, giving rise to the formation of density concentrations known as delta-shocks. For the isothermal gas system, the innnite speed of expansion into vacuum leads to zero timestep in the Godunov method ...

where n is a real constant andf(y) is a real-valued function of the variabley, hasmany applications inmathematical physics and astrophysics. Equation (1), for certain fixed values of n and f(y), models several phenomena such as the theory of stellar structure, the thermal behavior of a spherical cloud of gas, isothermal gaseous sphere, and the theory of thermionic currents [1–3]. Several method...

The possibility of producing chemical fuel (hydrogen) from the solar-thermal energy input using an isothermal cycling strategy is explored. The canonical thermochemical reactive oxide, ceria, is reduced under high temperature and inert sweep gas, and in the second step oxidized by H2O at the same temperature. The process takes advantage of the oxygen chemical potential difference between the in...

We have characterized the physical structure and chemical composition of two close-to-round starless cores in Taurus-Auriga, L1498 and L1517B. Our analysis is based on high angular resolution observations in at least two transitions of NH3, N2H + , CS, C 34 S, C 18 O, and C 17 O, together with maps of the 1.2 mm continuum. For both cores, we derive radial profiles of constant temperature and co...

Blade cooling is a relevant topic in the design of modern gas turbine engines, because of the increase in performance due to the resulting increase in the inlet turbine temperature is counteracted by a corresponding decrease due to the air extraction from the high-p compressor. In this paper, a previous model published by De Paepe & Dick is revisited and extended: while the original model consi...

This paper analyzes a compressible gas flow through a microchannel, and reports a complete set of first-order analytical solutions. Thiswork represents an extension of the previouswork ofArkilic on compressibleflows through amicrochannel. First, by comparing themagnitudes of different forces in the compressible gasflow,weobtain proper estimations for the Reynolds and Mach numbers at the channel...

The exact solution of the Euler equation, which describes time evolution a blast wave created by an intense explosion, is classic problem in gas dynamics. However, it has been found that analytical results do not match with from molecular dynamics simulation hard spheres two and three dimensions. In this paper, we show mismatch between theory simulations can be resolved considering Navier–Stoke...

The van der Waals forces across a very thin liquid layer (nanofilm) in contact with a plane solid wall make the liquid nonhomogeneous. The dynamics of such flat liquid nanofilms is studied in isothermal case. The Navier-Stokes equations are unable to describe fluid motions in very thin films. The notion of surface free energy of a sharp interface separating gas and liquid layer is disqualified....

We provide a complete picture to the self-gravitating non-relativistic gas at thermal equilibrium using Monte Carlo simulations, analytic mean field methods (MF) and low density expansions. The system is shown to possess an infinite volume limit in the grand canonical (GCE), canonical (CE) and microcanonical (MCE) ensembles when (N,V ) → ∞, keeping N/V 1/3 fixed. We compute the equation of stat...