As a clean fuel with the advantages of abundant reserves, high calorific value, renewability, and zero carbon emissions, hydrogen has broad application prospects in the fields of energy and power. Moreover, the mixing characteristics of hydrogen and air play a crucial role in determining combustion performance. A novel mixing method of hydrogen transverse jets into an air swirl flow was investigated via numerical and experimental approaches. The Schlieren technique and high-speed photography were employed in the experiments. The effects of various swirl numbers and jet momentum flux ratios on the flow field structure, its transient characteristics, and mixing properties were studied. The research results indicate that the complex vortex structure in the mean flow field is jointly affected by the swirl number and the jet momentum flux ratio. An increase in the jet momentum flux ratio has distinct effects on the flow unsteadiness for different swirl numbers, and there exists a critical value of the jet momentum flux ratio that substantially affects the degree of mixing and a characteristic length suitable for normalization of the axial coordinates when describing the centerline concentration decay. This study provides a reference and basis for further research on combustion in air swirl flows of hydrogen transverse jets.

中文翻译：

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氢气横向射流与空气旋流混合机制的数值和实验研究

氢作为一种清洁燃料，具有储量丰富、热值高、可再生、零碳排放等优点，在能源电力领域具有广阔的应用前景。此外，氢气和空气的混合特性在决定燃烧性能方面起着至关重要的作用。通过数值和实验方法研究了一种将氢气横向喷射到空气旋流中的新型混合方法。实验中采用了纹影技术和高速摄影。研究了不同旋流数和射流动量通量比对流场结构、瞬态特性和混合特性的影响。研究结果表明，平均流场中的复杂涡结构受到旋流数和射流动量通量比的共同影响。射流动量通量比的增加对不同旋流数的流动不稳定性有明显的影响，并且存在对混合程度有显着影响的射流动量通量比的临界值和适合轴坐标归一化的特征长度当描述中心线浓度衰减时。该研究为氢气横向射流空气旋流燃烧的进一步研究提供参考和基础。