多孔喷嘴的瞬态氢气射流特性研究

The use of carbon-free energy has become an important solution to achieve carbon neutrality and to cope with the environmental and climate crisis. This study aims to characterize the transient hydrogen jet characteristics of a multi-hole injector experimentally. In a constant volume chamber, a HDEV5 multi-hole injector was used to achieve hydrogen injection. Multiple groups of injection pressures and ambient pressures were set to achieve different injection-ambient pressure ratios. The hydrogen jet morphology was photographed using high-speed Z-type schlieren imaging technology. The results show that at a constant temperature, the axial penetration distance and projected area of the jet increase with the increase of the injection-ambient pressure ratio. When the pressure ratio is lower than 5.0, the hydrogen jet morphology exhibits certain self-similar characteristics. Based on the self-similar theory of gas jets, the proportional relationship of the penetration length of the hydrogen jet is calculated, and the penetration distance constant can be determined to be 39.2. The curvature results of the jet head contour show that the jet tends to expand outward under a larger injection pressure ratio.