4 research outputs found

    ON THE VALIDITY OF THE PRINCIPLE OF MINIMUM ENTROPY PRODUCTION

    Get PDF
    The purpose of this analysis is to show the importance of correct performance of picture representation and circumspect interpretation of variation in the application of the minimum entropy production principle. As an incorrect formulation of a variational task, written for the Fourier heat conduction problem has shown, the principle of minimum entropy production apparently goes to contradiction with the energy balance equation [1]. This led to further erroneous conclusions. The misunderstanding can be resolved - ex-ceeding far off beyond the actual problem with Gyarmati's picture representation and variational principle, the Governing Principle of Dissipative Processes

    A VARIATIONAL METHOD FOR SOLVING HEAT CONDUCTIONAL PROBLEMS

    Get PDF

    Wave theory of turbulence in compressible media (acoustic theory of turbulence)

    Get PDF
    The generation and the transmission of sound in turbulent flows are treated as one of the several aspects of wave propagation in turbulence. Fluid fluctuations are decomposed into orthogonal Fourier components, with five interacting modes of wave propagation: two vorticity modes, one entropy mode, and two acoustic modes. Wave interactions, governed by the inhomogeneous and nonlinear terms of the perturbed Navier-Stokes equations, are modeled by random functions which give the rates of change of wave amplitudes equal to the averaged interaction terms. The statistical framework adopted is a quantum-like formulation in terms of complex distribution functions. The spatial probability distributions are given by the squares of the absolute values of the complex characteristic functions. This formulation results in nonlinear diffusion-type transport equations for the probability densities of the five modes of wave propagation

    Wave theory of turbulence in compressible media

    Get PDF
    An acoustical theory of turbulence was developed to aid in the study of the generation of sound in turbulent flows. The statistical framework adopted is a quantum-like wave dynamical formulation in terms of complex distribution functions. This formulation results in nonlinear diffusion-type transport equations for the probability densities of the five modes of wave propagation: two vorticity modes, one entropy mode, and two acoustic modes. This system of nonlinear equations is closed and complete. The technique of analysis was chosen such that direct applications to practical problems can be obtained with relative ease
    corecore