| Journal: | Anais da Academia Brasileira de Ciencias |
| Database: | PERIÓDICA |
| System number: | 000409065 |
| ISSN: | 0001-3765 |
| Authors: | Colle, Sergio1 |
| Institutions: | 1Universidade Federal de Santa Catarina, Departamento de Engenharia Mecanica, Florianopolis, Santa Catarina. Brasil |
| Year: | 2017 |
| Season: | Jun |
| Volumen: | 89 |
| Number: | 2 |
| Pages: | 1313-1337 |
| Country: | Brasil |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Experimental, aplicado |
| English abstract | 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) |
| Disciplines: | Física y astronomía, Ingeniería |
| Keyword: | 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 |
| Full text: | Texto completo (Ver HTML) |
