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本文利用可视化高压定容弹,就常压环境下高速射流在破碎过程中的近场及远场的雾化特性随喷孔直径变化的规律进行实验研究。研究结果表明:对于远场喷雾来说,随着喷油压力和喷孔直径的增大,导致流动阻力的减小,从而导致贯穿加速度增大;而在近场区域,利用长焦显微技术拍摄的微观图像显示,随着喷雾的发展,液柱逐渐失稳,出现类似不稳定波的拟序结构;近场喷雾锥角随着喷孔直径的增大呈现增长的趋势,这是主要是因为长径比的减小导致流动阻力的减少,进而引起湍动能的增加,最终体现在法向湍流脉动速度的增加引起了锥角的增大。
In this paper, the visualization of the high pressure constant volume bomb, the atomization characteristics of the high velocity jet in the near field and the far field in the crushing process under normal pressure were experimentally studied with the variation of the nozzle diameter. The results show that for the far-field spray, as the injection pressure and nozzle diameter increase, the flow resistance decreases, which leads to the penetration acceleration increases. In the near-field region, the telephoto microscope The microscopic images show that with the development of the spray, the liquid column gradually becomes unstable and a quasi-structure similar to the unstable wave appears. The near-field spray cone angle increases with the increase of the diameter of the spray hole, which is mainly due to the long The decrease of the diameter ratio leads to the decrease of the flow resistance, which in turn leads to the increase of the turbulent kinetic energy. Finally, the increase of the normal turbulent pulsation velocity leads to the increase of the cone angle.