Thermodynamic bounds for existence of normal shock in compressible fluid flow in pipes



Título del documento: Thermodynamic bounds for existence of normal shock in compressible fluid flow in pipes
Revista: Anais da Academia Brasileira de Ciencias
Base de datos: PERIÓDICA
Número de sistema: 000409065
ISSN: 0001-3765
Autores: 1
Instituciones: 1Universidade Federal de Santa Catarina, Departamento de Engenharia Mecanica, Florianopolis, Santa Catarina. Brasil
Año:
Periodo: Jun
Volumen: 89
Número: 2
Paginación: 1313-1337
País: Brasil
Idioma: Inglés
Tipo de documento: Artículo
Enfoque: Experimental, aplicado
Resumen en inglés The present paper is concerned with the thermodynamic theory of the normal shock in compressible fluid flow in pipes, in the lights of the pioneering works of Lord Rayleigh and G. Fanno. The theory of normal shock in pipes is currently presented in terms of the Rayleigh and Fanno curves, which are shown to cross each other in two points, one corresponding to a subsonic flow and the other corresponding to a supersonic flow. It is proposed in this paper a novel differential identity, which relates the energy flux density, the linear momentum flux density, and the entropy, for constant mass flow density. The identity so obtained is used to establish a theorem, which shows that Rayleigh and Fanno curves become tangent to each other at a single sonic point. At the sonic point the entropy reaches a maximum, either as a function of the pressure and the energy density flux or as a function of the pressure and the linear momentum density flux. A Second Law analysis is also presented, which is fully independent of the Second Law analysis based on the Rankine-Hugoniot adiabatic carried out by Landau and Lifshitz (1959)
Disciplinas: Física y astronomía,
Ingeniería
Palabras clave: Dinámica de fluidos,
Ingeniería mecánica,
Tuberías de gas,
Flujo de gases,
Fluidos compresibles,
Análisis termodinámico
Keyword: Physics and astronomy,
Engineering,
Fluid dynamics,
Mechanical engineering,
Gas pipelines,
Gas flow,
Compressible fluids,
Thermodynamic analysis
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