Effective thermodynamic functions of a gas with solid particles

Using the relaxation formalism of nonequilibrium thermodynamics, a dynamic equation of state and hyperbolic thermal-conductivity equation are derived for a gas with solid particles.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 34, No. 6, pp. 1085–1089, June, 1978.     

On the possibility of Bose-Einstein condensation in a solid

We treat the question of the existence of Bose-Einstein condensation (BEC) in Bose lattice systems. Simple examples are constructed that do display BEC while having a lattice symmetry. It is suggested, however, that these systems are not crystals in the ordinary sense. When a more conventional definition of a lattice is employed, we generalize the proof of Matsuda and Tsuneto that BEC does not exist in a Bose lattice, for a wider class of wave functions including two-body correlations. A solid with a finite vacancy concentration can display BEC, which is related to the BEC in the vacancy gas. We clarify the relation between BEC of vacancies and particles.     

Calculation of the thermodynamic parameters of helium in a centrifugal force field

The design of cooling systems for a cryoalternator's superconducting field windings must be based on the knowledge of the distribution of the thermodynamic parameters (primarily temperature) of the helium in both its liquid and gaseous phases in centrifugal force fields. This paper proposes a set of ordinary differential equations describing the distributions. By numerically solving the set, the effects of the angular velocity of rotation, filling factor and temperature (pressure) at the axis of rotation upon the pressure, temperature and density distributions in helium in rotating vessels have been studied. Formulee for the approximation of the distributions have been obtained, which are applicable to rotation axis temperatures from 3 to 4.6 K (corresponding to saturation pressures 0.24 × 10⁵ to 1.4 × 10⁵ Pa), angular velocities of rotation from 50 to 300 rad s^?1 and filling factors from 0.1 to 0.9.     

The thermodynamic expansion of a heated gas

The thermodynamic expansion index is determined for a gas being evacuated from a reservoir with allowance for heat transfer.     

Inherent frame dependence of thermodynamic fields in a gas

Summary Grad's 13-moment theory – appropriate for rarefied gases – implies that a gas cannot perform a rigid rotation, if it conducts heat. Indeed, stationary heat conduction in a gas between co-axial cylinders at rest in a non-inertial frame exhibits azimuthal components of velocity and heat flux. The fields of velocity and heat flux are calculated. The effects are due to Coriolis terms in all transfer equations that result from the Boltzmann equation.     

The thermodynamic driving force for bone growth and remodelling: a hypothesis

The Eshelby stress (static energy momentum) tensor is derived for bone modelled as an inhomogeneous piezoelectric and piezomagnetic Cosserat (micropolar) medium. The divergence of this tensor is the configurational force felt by material gradients and defects in the medium. Just as in inhomogeneous elastic media, this force is identified with the thermodynamic force for phase transformations, in bone it is the thermodynamic cause of structural transformations, i.e. remodelling and growth. The thermodynamic approach shows that some terms of driving force are proportional to the stress, and some acting on material inhomogeneities are quadratic in the stress-the latter outweigh by far the former. Since inertial forces due to acceleration enter the energy-momentum tensor, it follows that the rate of loading matters and that both tension and compression stimulate growth, which is favoured at heterogeneities.     

On the possibility of acoustic probing of gas wells

The possibility of probing the critical areas of gas wells using acoustic signals is analyzed. The results of investigations on the evolution of acoustic waves in cylindrical channels with permeable portions surrounded by a porous space are presented. The quantitative and qualitative features of the dynamics of waves as a function of the state of an inhomogeneous porous medium are established. Results showing that the state of the reservoir characteristics of rocks has a substantial influence on the evolution of acoustic signals are obtained. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 80, No. 4, pp. 118–126, July–August, 2007.     

Calculating the properties of a real gas from tables of thermodynamic functions

The feasibility of applying numerical differentiation methods to tables of thermodynamic functions is demonstrated on several numerical examples.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 24, No. 4, pp. 735–739, April, 1973.     

Mass transfer between the gas and solid particles in a fluidized bed

A model of the boundary layer and condition of suspension of a solid particle by a gas flow is used to formulate analytical correlations, which are then compared with experiment.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 41, No. 6, pp. 1067–1072, December, 1981.     

The stresses produced in a semi-infinite solid by a moving surface force

The problem considered here is that of a semi-infinite homogeneous isotropic elastic solid to the surface of which are applied forces moving with uniform velocity. The forces are assumed to act for all time, so that the problem is quasi-static. The cases of applied normal force and applied shear force are both considered. The types of applied load considered are those of a point force and of a force which is distributed over either a circular or a rectangular area. The basic equations are solved by means of integral transforms, and the resulting multiple integrals are reduced to single finite integrals which may be evaluated numerically when the velocity of the applied force is below that of Rayleigh waves for the solid. Numerical results are presented in graphical form for the displacement and stress components at points below the point of application of the point force and for the stress components at points below the centre of the loaded area for distributed loading.