Numerical solution of highly expanded flashing liquid jets

Angelo E.; Simoes-Moreira J.R.

Numerical solution of highly expanded flashing liquid jets

Tipo

Artigo

Data de publicação

2007

Periódico

Journal of Thermophysics and Heat Transfer

Citações (Scopus)

12

Autores

Angelo E.
Simoes-Moreira J.R.

Resumo

Numerical simulation was carried out from a two-dimensional axisymmetric model for the expansion region of a flashing liquid jet expanding into a low-pressure environment Typically, the flashing phenomenon is observed in laboratory experiments in which a liquid jet flows through a nozzle into a low-pressure environment, well below the saturation pressure of the liquid at the injection temperature. The present model considers that the fluid remains in the liquid phase down to the exit plane and off the nozzle, reaching high degrees of superheating or metastability, and then the metastable liquid jet undergoes a sudden phase change through an evaporation wave process. The numerical solution was carried out in two parts. In the first part, the theory of oblique evaporation waves was applied to solve the jump equations of the fast evaporation that occurs on the surface of the metastable liquid core. In the second part, the problem of the expansion region that results from the evaporation process was analyzed. This region is formed by a high-speed two-phase region and, generally, culminates with the formation of a shock wave structure enveloping the liquid core. The classical finite differences explicit method of MacCormack and a shock-capturing scheme were used, along with an accurate equation of state. Main shock wave dimensions obtained from the numerical solution were in agreement with the measured ones. Copyright © 2007 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

Assuntos Scopus

Evaporation waves , Jump equations , Metastable liquids