Direct Contact Condensation in Falkner-Skan Flows

2002 ◽  
Author(s):  
J. Davis ◽  
G. Yadigaroglu
Keyword(s):  
Parametric Study ◽  
Direct Contact ◽  
Saturated Vapor ◽  
Subcooled Liquid ◽  
Contact Condensation ◽  
Two Fluid

In this paper we present a method for solving direct contact condensation problems involving Falkner-Skan flows. Using this method we then perform a parametric study for the problem of coupled two-fluid (saturated vapor on subcooled liquid) stagnation flows with direct contact condensation. Selected results and the resulting correlations are discussed.

A Physically Based, One-Dimensional Two-Fluid Model for Direct Contact Condensation of Steam Jets Submerged in Subcooled Water

2015 ◽  
Vol 1 (2) ◽  
Author(s):  
David Heinze ◽  
Thomas Schulenberg ◽  
Lars Behnke
Keyword(s):  
Direct Contact ◽  
Two Phase Flow ◽  
Fluid Model ◽  
Interfacial Area ◽  
Phase Flow ◽  
Two Phase ◽  
One Dimensional ◽  
Two Fluid Model ◽  
Contact Condensation ◽  
Two Fluid

A simulation model for the direct contact condensation of steam in subcooled water is presented that allows determination of major parameters of the process, such as the jet penetration length. Entrainment of water by the steam jet is modeled based on the Kelvin–Helmholtz and Rayleigh–Taylor instability theories. Primary atomization due to acceleration of interfacial waves and secondary atomization due to aerodynamic forces account for the initial size of entrained droplets. The resulting steam-water two-phase flow is simulated based on a one-dimensional two-fluid model. An interfacial area transport equation is used to track changes of the interfacial area density due to droplet entrainment and steam condensation. Interfacial heat and mass transfer rates during condensation are calculated using the two-resistance model. The resulting two-phase flow equations constitute a system of ordinary differential equations, which is solved by means of the explicit Runge–Kutta–Fehlberg algorithm. The simulation results are in good qualitative agreement with published experimental data over a wide range of pool temperatures and mass flow rates.

CFD Analysis of Direct Contact Condensation (DCC) of Subsonic Steam Jets in a Cross-Flow of Water Using a Two-Fluid Model

2018 ◽  
Author(s):  
Jayachandran K. Narayanan ◽  
Arnab Roy ◽  
Parthasarathi Ghosh
Keyword(s):  
Heat Transfer ◽  
Direct Contact ◽  
Fluid Model ◽  
Cross Flow ◽  
Liquid Oxygen ◽  
Transfer Coefficients ◽  
Flowing Liquid ◽  
High Heat Transfer ◽  
Contact Condensation ◽  
Two Fluid

Direct contact condensation occurs when a vapor comes in contact with the liquid of the same fluid and is accompanied by very high heat transfer coefficients compared to the conventional heat exchanging processes. Many researchers have investigated the direct contact condensation of steam jets in a pool of subcooled water. In the last decade, the potential of flowing liquid as an enhanced heat transfer medium in comparison with the stationary pool of liquid was explored by various researchers. Also, in some configurations of staged combustion cycle based rocket engine, the oxygen-rich gas is injected into flowing liquid oxygen to improve the heat transfer characteristics. Hence, there is a need to investigate the direct contact condensation of vapor jets in a cross flow of liquid. A two-fluid particle based multiphase formulation with thermal phase change model has been implemented in the present investigation to capture the direct contact condensation phenomena. The data obtained from numerical simulations are validated with the experimental results of Clerx et al., [1]. Further, studies on plume shapes, interfacial area and pressure amplitudes are reported.

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