Numerical investigations on unstable direct contact condensation of cryogenic fluids

26th International Cryogenic Engineering Conference & International Cryogenic Materials Conference 2016

材料科学;物理学

Jayachandran, K.N.^1 ; Arnab, Roy^2 ; Parthasarathi, Ghosh^1

Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur, West Bengal

721302, India^1

Department of Aerospace Engineering, Indian Institute of Technology, Kharagpur, West Bengal

721302, India^2

关键词: Combustion products;    Direct contact condensation;    Heat and mass transfer;    Numerical investigations;    Staged combustion;    Steam-water mixture;    Subcooled liquid oxygen;    Thermal phase change models;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/171/1/012052/pdf
DOI  :  10.1088/1757-899X/171/1/012052

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

A typical problem of Direct Contact Condensation (DCC) occurs at the liquid oxygen (LOX) booster turbopump exit of oxidiser rich staged combustion cycle based semi-cryogenic rocket engines, where the hot gas mixture (predominantly oxygen and small amounts of combustion products) that runs the turbine mixes with LOX from the pump exit. This complex multiphase phenomena leads to the formation of solid CO2& H2O, which is undesirable for the functioning of the main LOX turbopump. As a starting point for solving this complex problem, in this study, the hot gas mixture is taken as pure oxygen and hence, DCC of pure oxygen vapour jets in subcooled liquid oxygen is simulated using the commercial CFD package ANSYS CFX®. A two fluid model along with the thermal phase change model is employed for capturing the heat and mass transfer effects. The study mainly focuses on the subsonic DCC bubbling regime, which is reported as unstable with bubble formation, elongation, necking and collapsing effects. The heat transfer coefficients over a period of time have been computed and the various stages of bubbling have been analysed with the help of vapour volume fraction and pressure profiles. The results obtained for DCC of oxygen vapour-liquid mixtures is in qualitative agreement with the experimental results on DCC of steam-water mixtures.