Topical Problems of Fluid Mechanics


Institute of Thermomechanics AS CR, v.v.i.	CTU in Prague Faculty of Mech. Engineering Dept. Tech. Mathematics	MIO Université du Sud Toulon Var - AMU - CNRS - IRD	Czech Pilot centre ERCOFTAC

Performance of Simple Condensation Model in High-Pressures
Hric V., Halama J.
Abstract:
In this article we deal with the numerical solution of two-phase flow with nonequilibrium condensation in high pressures. We test how simple homogeneous non-equilibrium mixture model (single-fluid model) performs in high-pressure conditions. For this purpose we used our in-house CFD code with the following limitation: time-dependent compressible Euler equations in 2D for mixture of dry steam and water droplets, standard method of moments for liquid phase, simple fitting of liquid saturation data, so-called special gas equation provided by Wagner and Pruss (IAPWS-95) used as real equation of state for both superheated and supersaturated dry steam, classical nucleation theory and droplet growth model with appropriate corrections. As a test case we used rapid expansion of high-pressure steam in convergent-divergent nozzle with supersonic outlet in which condensation occurs in the divergent part. Test cases come from work of Bakhtar et al [1], [2]. We used all three nozzle geometries and two distinct cases for each (six test cases in total). Results of our simulations are in a reasonable accordance with the experimental data, several simplifications taking into account.
Keywords:
nozzle, high pressure, condensation, nucleation, method of moments

Fulltext: PDF DOI: http://dx.doi.org/10.14311/TPFM.2016.009

In Proceedings Topical Problems of Fluid Mechanics 2016, Prague, 2016 Edited by David Šimurda and Tomáš Bodnár, pp. 59-68 ISBN 978-80-87012-58-1 (Print) ISSN 2336-5781 (Print)