Simulation of two-phase flow of hydrogen at cryogenic conditions

摘要

In this paper simulation results of two- phase flow of hydrogen are presented and compared to measurement data of respective experimental investigations. The aim of the simulation is the prediction of pressure losses due to different flow conditions (e.g. mass flow rate), geometries, and heat flows (q or T_(ambient) = const.). The studies were initiated by the EU- project 'CRYOPLANE- Hydrogen Fuelled Aircraft- System Analysis' supported within the Fifth Framework Program of the European Commission. The study is divided into three parts. The first part is the measurement of pressure drops of liquid/gaseous hydrogen in a pipe with an inner diameter of 4 mm and a total length of 3,2 m. The hydrogen mass flow and the radial heat flow are varied. This data is used to validate the results of a one- dimensional short-cut model realized with MATLAB/SIMULINK. This simulation is the second part of the study. This simulation is mainly supposed to be used for hydrogen flow through straight pipes and includes the two-phase flow correlation of Friedel, insulation characteristics, heat transfer correlations, and variable hydrogen properties. The comparison of simulation results to experimental data shows a good agreement. This simulation tool has two different areas of application. The first is the simulation of an online fuel monitoring system and the dimensioning of the pipe system within the CRYOPLANE-project, the second application is the creation of a comparison tool for CFD-simulations. The CFD-simulation is the third part. The simulations are performed with PHOENICS, a CFD- code based on the method of finite volumes. Because of the limited scale, and the conference topic, this simulation is only briefly mentioned and not discussed in detail. The main purpose of this simulation is the modelling of turbulence effects of two-phase flows.