Behavior of hydrogen hollow-cone spray depending on the ambient pressure

Effect of injection and ignition timing on a hydrogen-lean stratified charge combustion engine

“…Therefore, an extremely high degree of fuel stratification could reduce the HRR through the contraction of the hydrogen jet. Based on a previous study, 32 the contraction of the jet structure prolonged the ignition delay with a stable combustion detected. Although the flammable mixture was not directly located at the periphery of the spark plug, the plasma state of the arc discharge channel was stretched to the contracted jet area, which has a lower static pressure.…”

“…Moreover, the hydrogen diffusion rate can be enhanced when the injection timing was advanced owing to a low ambient pressure. 32 The advanced injection timing did not appropriately stratify hydrogen but dispersed it and finally, a behavior similar to lean homogeneous charge combustion was observed. After the injection timing was retarded toward the top dead center (TDC), the peak HRR increased and hard combustion was dominant.…”

“…Studies have experimentally investigated the jet behavior of high-pressure hydrogen DI. 31–33 Salazar and Kaiser 34 visualized the formation of the mixture of DI hydrogen with an acetone seeder for planar laser-induced fluorescence diagnostics in a research engine. The wall interaction of hydrogen may enhance the mixture for stable operation depending on the injection timing.…”

The role of hydrogen for future internal combustion engines

“…The investigation of a high-pressure hydrogen jet is required by means of both experimental optical diagnostics and numerical CFD modelling. Some preliminary research on the evolution of a hollow-cone-shaped hydrogen jet is described in Lee et al 50,51 and Roy et al 52 The formation of hydrogen mixture fraction by laser-induced breakdown spectroscopy is described in Roy et al 52 It was observed that hydrogen rich-combustion emits a visible range of wavelengths, as shown in Lee et al, 51 Shudo and Oba 53 and Schefer et al 54 and presented in Figure 4.…”

Effect of Low Ambient Pressure on Spray Cone Angle of Pressure Swirl Atomizer

“…Chen et al [12] studied the spray characteristics of swirl atomizer by using a high-speed shadowgraph system under high ambient pressure; the results show that spray is suppressed by ambient pressure, a critical pressure value was found at which the spray structure converts from a wide hollow cone to a narrow contracting bell, and the discharge coefficient increases while the spray cone angle decreases. Lee et al [13] reveal that high ambient pressure decreases the vertical extent of the spray penetration and its area.…”