【摘要】 为研究射流偏心撞击对凝胶撞击雾化的影响,建立撞击雾化实验台,制备凝胶推进剂及其模拟液,对单股射流形态及不同偏心度下的撞击液膜和液滴尺寸分布进行测量。理论推导了偏心撞击下撞击液膜偏角,并与实验结果进行了对比。研究表明:随着喷射速度的增大,单股射流受到的扰动逐渐增大;在靠近喷注器出口处扰动有限,不同速度下的射流变形都很小;不同偏心度下液膜发展和破碎形式基本相同,当偏心度达到1.5/6时,液膜自撞击点开始出现了呈一定角度较为暗淡的区域,流量不对称性增强;随着偏心度的增大,液膜偏角逐渐增大,但与理论值相比偏小;偏心度的大小对撞击雾化的液滴尺寸分布影响较小,但偏心撞击的索特平均直径值比无偏心时小,并在0.5/6达到最小值。更多还原

【Abstract】 In order to study the effect of eccentric impact of jet on the impinging atomization of gel propellant,a relative experimental system is established,and a gel propellant as well as a simulant are prepared. Jet behavior,impinging liquid sheet and droplet size distribution at different eccentricities are measured. Spray incline angle is deduced theoretically and compared to the experimental results under eccentric impingement. The results indicate that the disturbances on jets are strengthened with increase in jet velocity. However,the deformations of the jets near injectors are all very small at different jet velocities since the disturbance is limited. The development and breakup of liquid sheet are basically the same under different eccentricities. While the eccentricity exceeds 1. 5 /6,two darker regions with a certain angle appear at the impinging point,resulting in the enhancement of flux nonsymmetry. As the eccentricity is improved,the spray incline angle enlarges and is less than the theoretical result. The eccentricity has a little influence on the droplet size distribution of impinging atomization,but Sauter mean diameter( SMD) with eccentricity is always lower than that without eccentricity. And SMD reaches the smallest when the eccentricity equals to 0. 5 /6.更多还原