On the entrainment assumption in Schatzmann's integral plume model

• Tipo: Artigo em Revista Científica Internacional
• Data: 1997

Autores

Teixeira, MAC (Autor) Outra; Miranda, PMA (Autor) Outra

Revista

Título: Flow, Turbulence and Combustion

Vol. 57

Páginas: 15-42

ISSN: 1386-6184

Editora: Springer Nature

Indexação

ISI Web of Knowledge - 6 Citações

Scopus - 8 Citações

Outras Informações

ID Authenticus: P-001-C6J

DOI: 10.1007/bf02528762

Abstract (EN): The behaviour of stationary, non-passive plumes can be simulated in a reasonably simple and accurate way by integral models. One of the key requirements of these models, but also one of their less well-founded aspects, is the entrainment assumption, which parameterizes turbulent mixing between the plume and the environment. The entrainment assumption developed by Schatzmann and adjusted to a set of experimental results requires four constants and an ad hoc hypothesis to eliminate undesirable terms. With this assumption, Schatzmann's model exhibits numerical instability for certain cases of plumes with small velocity excesses, due to very fast radius growth. The purpose of this paper is to present an alternative entrainment assumption based on a first-order turbulence closure, which only requires two adjustable constants and seems to solve this problem. The asymptotic behaviour of the new formulation is studied and compared to previous ones. The validation tests presented by Schatzmann are repeated and it is found that the new formulation not only eliminates numerical instability but also predicts more plausible growth rates for jets in co-flowing streams.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 28