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研究气体的喷射特性,用于指导发动机燃油供给系统的设计和燃烧室有效组织燃烧。基于粒子图像测速技术(PIV),对不同温度、不同压差下气体喷射的特性进行了对比研究。通过试验分析和图像处理等手段对射流流场及涡结构、气体射流边界扩展、喷嘴轴向流速衰减规律、断面流速分布等进行了总结。试验表明:射流边界呈线性扩展,可用锥角大小来表征其特性,锥角随压差的减小而增大,且增幅明显,温度对其也有一定影响。喷嘴射流的轴向速度与射流距离成反比,而速度的影响面积随射流距离的增大而增大,温度的增大使得相同压差下的轴向速度相应增大,断面流速的分布存在很大的相似性。
The injection characteristics of the gas are studied to guide the design of the engine fuel supply system and the efficient combustion of the combustion chamber. Based on Particle Image Velocimetry (PIV), the characteristics of gas injection at different temperatures and pressure differences were compared. The jet flow field and vortex structure, the expansion of gas jet boundary, the attenuation law of nozzle axial flow velocity and the distribution of flow velocity in section were summarized through experimental analysis and image processing. The experimental results show that the boundary of jet increases linearly, and the taper angle can be used to characterize its characteristics. The taper angle increases with the decrease of pressure difference, and increases obviously. Temperature also has some influence on it. The axial velocity of nozzle jet is inversely proportional to the jet distance, while the influence area of velocity increases with the increase of jet distance. The increase of temperature leads to a corresponding increase of axial velocity under the same pressure drop. Great similarity.