Macroscopic approach to reciprocal relations in irreversible thermodynamics.
Validity of Onsager-Casimir reciprocal relations with theoretical framework of macroscopic nonequilibrium thermodynamics
MACROSCOPIC EQUATION↗
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Bubble formation and growth - Study of the boundary conditions at a liquid-vapor interface through irreversible thermodynamics Quarterly progress report, Mar. - May 1966
Nonequilibrium effect on vapor bubble growth determined in study of boundary conditions at liquid-vapor interface
NONEQUILIBRIUM↗
Correlation between nonequilibrium thermodynamic theory and V-I curves of a thermionic converter
The methods of irreversible thermodynamics are used as a basis for developing a transport theory applicable to thermionic cesium diodes. This theory is applied in describing certain aspects of experimental voltage-current (V-I) characteristic curves of a thermionic diode. Emphasis is placed on the open-circuit voltage and short-circuit current of the V-I curves. Experimental results show that the open-circuit voltage is essentially independent of the interelectrode spacing, whereas the short-circuit current varies inversely with the interelectrode separation. The inverse dependence is in agreement with the results of the present analysis and also with results expected from diffusion theory, which has been used in other analyses. In fact, the theory used in this investigation reduces to diffusion theory under special assumptions. Deviations from diffusion theory, which were found in experimental results, can be accounted for using the theory developed in this paper.
Robinson, L. B.↗
Some aeroacoustic and aerodynamic applications of the theory of nonequilibrium thermodynamics
An exact equation is derived for the dissipation function of a homogeneous, isotropic, Newtonian fluid, with terms associated with irreversible compression or expansion, wave radiation, and the square of the vorticity. This and other forms of the dissipation function are used to identify simple flows, such as incompressible channel flow, the potential vortex with rotational core, and incompressible, irrotational flow as minimally dissipative distributions. A comparison of the hydrodynamic and thermodynamic stability characteristics of a parallel shear flow suggests that an association exists between flow stability and the variation of net dissipation with disturbance amplitude, and that nonlinear effects, such as bounded disturbance amplitude, may be examined from a thermodynamic basis.
Horne, W. Clifton↗
A proposed approach to the application of nonlinear irreversible thermodynamics to fracture in composite materials
The fracture criteria upon which most fracture mechanics is based involves an energy balance that is not appropriate for the fracture mechanics of viscoelastic materials such as polymer matrix composites. A more appropriate criterion based upon nonequilibrium thermodynamics and involving a power balance rather than an energy balance is proposed. This crierion is based upon a reformulation of the second law of thermodynamics which focuses attention on the total Legendre transform of energy expressed as a functional over time and space. This excess energy functional can be shown to be equivalent to the Rice J integral if the only irreversible process is the propogation of a single crack completely through the thickness of the specimen and if the crack propogation is assured to be independent of time. For the more general case of more than one crack in a viscoelastic medium integration over both time and space is required. Two experimentally measurable parameters are proposed which should permit the evaluation of this more general fracture criterion.
Lindenmeyer, P. H.↗
Extrema principles of entrophy production and energy dissipation in fluid mechanics
A survey is presented of several extrema principles of energy dissipation as applied to problems in fluid mechanics. An exact equation is derived for the dissipation function of a homogeneous, isotropic, Newtonian fluid, with terms associated with irreversible compression or expansion, wave radiation, and the square of the vorticity. By using entropy extrema principles, simple flows such as the incompressible channel flow and the cylindrical vortex are identified as minimal dissipative distributions. The principal notions of stability of parallel shear flows appears to be associated with a maximum dissipation condition. These different conditions are consistent with Prigogine's classification of thermodynamic states into categories of equilibrium, linear nonequilibrium, and nonlinear nonequilibrium thermodynamics; vortices and acoustic waves appear as examples of dissipative structures. The measurements of a typical periodic shear flow, the rectangular wall jet, show that direct measurements of the dissipative terms are possible.
Horne, W. Clifton↗
Extrema principles of entropy production and energy dissipation in fluid mechanics
A survey is presented of several extrema principles of energy dissipation as applied to problems in fluid mechanics. An exact equation is derived for the dissipation function of a homogeneous, isotropic, Newtonian fluid, with terms associated with irreversible compression or expansion, wave radiation, and the square of the vorticity. By using entropy extrema principles, simple flows such as the incompressible channel flow and the cylindrical vortex are identified as minimal dissipative distributions. The principal notions of stability of parallel shear flows appear to be associated with a maximum dissipation condition. These different conditions are consistent with Prigogine's classification of thermodynamic states into categories of equilibrium, linear nonequilibrium, and nonlinear nonequilibrium thermodynamics; vortices and acoustic waves appear as examples of dissipative structures. The measurements of a typical periodic shear flow, the rectangular wall jet, show that direct measurements of the dissipative terms are possible.
Horne, W. Clifton↗