Transient supersonic release of hydrogen from a high pressure vessel: A computational analysis

Numerical study of the near-field of highly underexpanded turbulent gas jets

“…Being more close to the objectives of the present paper, Peneau et al [8] reported the position of the Mach disk to vary significantly during the release of hydrogen from a high-pressure tank ð100 atmÞ up to t à ¼ 80 (corresponds to an end of the simulation). However, the measurements of Lacerda [28] demonstrated that for light gases Mach disk takes relatively longer time to stabilize around the location predicted by a steady theory [12] or [15].…”

“…Ishii et al [7], Pè neau et al [8], among others). Pè neau et al [8] studied both the one-component and two-component (hydrogen-air) releases. However, a total time of these computations was rather limited and thus a quasi steady state has not been reached.…”

Self-ignition and explosion of a 13-MPa pressurized unsteady hydrogen jet under atmospheric conditions

“…Unfortunately, we are not aware of the experimental works on the formation of an axisymmetric hydrogen jet at large off-design condition ratios (similarity factor [9]) n ¼ P n /Р ∞ (P n is the nozzle exit section pressure). Among the publications devoted to the computer analysis of unsteady underexpanded hydrogen jets, the work closest in the similarity of modeled conditions is paper [9], where hydrogen is considered as an ideal gas. Here the flow at the nozzle cut is assumed to be sonic (in our case, outflow through the opening) and the quantity n ¼ 47.…”

“…Bearing in mind that the geometric parameters of the stationary flow structure (Mach disk position and diameter, "barrel" diameter, etc.) are usually proportional to n 1/2 or N 1/2 , where N]P 0 /Р ∞ [9,20], the choice of work [9] for a subsequent comparison is justified. Adopting the definitions and notation of [9], we will present our results on the bow shock propagation in generalized variables t* ¼ tU n /D and x* ¼ x/D (U n is the hydrogen velocity in the exit section of the sonic nozzle (opening) of diameter D equal to the local sonic velocity, at T 0 ¼ 291 K U n ¼ 1190 m/s).…”

“…Four variants of holder 4 were used. The diameter D of the opening that forms the outflowing jet is equal to 6,9,12, and 15 mm. The vessel was filled with hydrogen slowly in order not to create a spontaneous diaphragm rupture.…”