Numerical study on unsteady characteristics of high-pressure hydrogen jet ejected from a pinhole

The aim of this study was to delineate the unsteady fluid dynamics of the high-pressure hydrogen jet to clarify the relationship between the forced ignition position and the flame development characteristics in a high-pressure hydrogen jet leaking from a pinhole. The Navier-Stokes equation for a compressible multi-component gas was used to simulate a high-pressure (82 MPa stagnation pressure) unsteady hydrogen jet ejected into the at-mosphere through a pinhole (diameter = 0.2 mm). The results indicated that the flapping jet at the base of the jet formed a cloud of highly concentrated hydrogen that flowed downstream. A correlation was observed between the spatio-temporal distribution of hydrogen concentration and velocity was observed. The unsteady high-pressure hydrogen jet obtained by simulation will be used in subsequent studies focusing on flame develop-ment under forced ignition.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The aim of this study was to investigate the unsteady fluid dynamics of high-pressure hydrogen jets. Simulation results showed the formation of a highly concentrated cloud of hydrogen at the base of the jet, with observed correlation between the spatio-temporal distribution of hydrogen concentration and velocity.