Experimental and numerical investigation of hydrogen gas auto-ignition

Experimental investigation on shock waves generated by pressurized gas release through a tube

“…This implies that high-pressure hydrogen leak has a very high fire risk. However, according to the experimental results (Dryer et al, 2007;Golub et al, 2008Golub et al, , 2009Mogi et al, 2009;Lee et al, 2011;Kim et al, 2013), the minimum release pressure of spontaneous ignition of hydrogen was slightly greater than the theoretical critical pressure (1.63 MPa), which was not less than 2.04 MPa reported by Dryer et al (2007). This might be caused by the following reasons:…”

“…A barrel shock structure was formed as a result of the compression waves accumulation. Due to highly turbulent hydrodynamics, the classical shock structures such as the Mach disk and the barrel shock, might be hidden in the high-speed jet, and could not be clearly observed in the schlieren images (Golub et al, 2009). …”

Simulation of mild auto-ignition initiated by a hot spot

“…In a hydrogen engine, auto-ignition can be initiated by hot spots that are produced from hot residual gas, heated particles, or remaining electric charge at the spark plug, and can take place at different timing during engine operation. For instance, auto-ignition can occur during the opening of the intake valve, referred to as backfiring, whereas the auto-ignition occurring during the compression stroke with the intake valve closed is known as pre-ignition [3]. For SI engines, auto-ignition can also cause engine knock.…”

Self-ignition of hydrogen–nitrogen mixtures during high-pressure release into air

“…In recent years one could observe an increased interest in hydrogen technologies and safety issues corresponding to them, including uncontrolled ignition during discharge into the air from high-pressure installations. Latest experimental [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] as well numerical [19][20][21][22][23][24] works focus mainly on the detailed description of the self-ignition mechanism according to different initial and boundary conditions including: extension channel geometry: diameter [4][5][6][7]19], length [5][6][7][8][9][10][11][12][13][14][15][16][17][20][21][22], cross-section shape [7,8,18,23] or obstacle presence in front of the hydrogen stream [18,…”