Wang Yufan, Chai Pingping, Yao Feng, Chen Hongyu, Shi Zhehang, Zhao Hui, Li Weifeng, Liu Haifeng
National Energy Coal Gasification Technology Research and Development Center, Shanghai Engineering Research Center of Coal Gasification, Engineering Research Center of Resource Utilization of Carbon-containing Waste with Carbon Neutrality, Ministry of Education, East China University of Science and Technology, Shanghai 200237, China.
Department of Mathematics, East China University of Science and Technology, Shanghai 200237, China.
Soft Matter. 2023 Aug 2;19(30):5781-5794. doi: 10.1039/d3sm00583f.
This study aims to experimentally and theoretically investigate the roles of a threaded nozzle and yield stress in the coaxial air blast atomization of a gelled jet by means of rheological tests and high-speed flow visualization techniques. Similar to the breakup types of Newtonian fluids, a gelled jet will gradually exhibit an oscillation mode, membrane-type breakup, fiber-type breakup and a superpulsating submode as the airflow velocity increases. The transition conditions for each type are determined and plotted in the dimensionless map of We-Oh. For the jet spray angle, the maximum occurs when We = 600 and is clearly enlarged by the gas-side thread in the nozzle. The numerical results of the linear stability analysis indicate that a smaller dominant unstable growth rate is acquired by swelling the yield stress, while the higher dominant unstable growth rate and truncated wavenumber appear as the rotational airflow is acquired through the gas-side threaded nozzle.
本研究旨在通过流变学测试和高速流动可视化技术，对螺纹喷嘴和屈服应力在凝胶射流同轴空气雾化中的作用进行实验和理论研究。与牛顿流体的破碎类型相似，随着气流速度增加，凝胶射流将逐渐呈现振荡模式、膜状破碎、纤维状破碎和超脉动子模式。确定了每种类型的转变条件，并绘制在We-Oh无量纲图中。对于射流喷雾角，当We = 600时出现最大值，并且喷嘴中的气体侧螺纹明显扩大了该值。线性稳定性分析的数值结果表明，增大屈服应力会获得较小的主导不稳定增长率，而通过气体侧螺纹喷嘴获得旋转气流时会出现较高的主导不稳定增长率和截断波数。
