Suscripción a Biblioteca: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

Dispersion of High Pressure Underexpanded Helium Jets into the Atmosphere

Get access (open in a dialog) DOI: 10.1615/IHTC15.cpm.009337
pages 1765-1775

Sinopsis

Hydrogen will play an important role in the energy supply for future low carbon societies so many countries are now developing large scale hydrogen fuel supply systems for hydrogen powered vehicles. However, there are still significant hydrogen safety issues that need to be addressed so that wide spread use of hydrogen fueling systems will have the same or lower levels of risk as conventional fossil fuel systems. This study describes numerical studies of hydrogen leaks from high pressure storage tanks that result in underexpanded jets into the surrounding atmosphere. An axisymmetric CFD model was used to predict the velocity, temperature and concentration distributions within the supersonic jet and downstream of the Mach disk during steady state discharges for stagnation pressures up to 70 MPa. The numerical results compare well with previous experimental data. The numerical results are then used to show that most of the hydrogen flow bypasses the Mach disk and flows in the expansion region outside of the barrel shock. This partitioning of the flow results in a significant amount of supersonic flow downstream of the Mach disk which significantly expands the hydrogen dispersion region. This flow partitioning must be considered in future notional nozzle models of flows in highly underexpanded jets.