Deflagration-to-detonation Transition Due to a Pressurised Release of a Hydrogen Jet. First Results of the Ongoing TAU_NRCN-CEA Project

A sudden release of compressed gases and the formation of a jet flow can occur in nature and various engineering applications. In particular, high-pressure hydrogen jets can spontaneously ignite when released into an environment that contains oxygen. For some scenarios, these high-pressure hydrogen jets can be released into a mixture containing hydrogen and oxygen. This scenario can possibly lead to a wide range of combustion regimes, such as jet flames, slow or fast deflagrations, or even hazardous detonations. Each combustion regime is characterized by typical pressures and temperatures, however, fast transition between regimes is also possible.
A common project between Tel Aviv University (TAU), Nuclear Research Center Negev (NRCN) and Commissariat à l’Energie Atomique et aux énergies alternatives (CEA) has been recently launched in order to understand these phenomena from experimental, modelling and numerical points of view. The main goal is to investigate the dynamics and combustion regimes that arise once a pressurized hydrogen jet is released into a reactive environment that contains inhomogeneous concentrations of hydrogen, steam, and air.
In this paper we present the first numerical results describing high-pressure hydrogen release obtained using a massively parallel compressible structured-grid flow solver. The experimental arrangements devoted to this phenomenon will also be described.