摘要
固体火箭发动机燃烧室中存在大量熔融态凝相Al_(2)O_(3)液滴,其运动与碰撞特性对发动机两相流损失与比冲性能有重要影响。本文采用流体体积法模拟固体火箭发动机中熔融态Al液滴碰撞过程,并实验验证了算法的可靠性。开展熔融态Al_(2)O_(3)液滴碰撞过程研究,着重关注其中的液滴偏心碰撞过程,揭示了韦伯数、碰撞参数、液滴尺寸等对液滴碰撞结果的影响,获得了反弹、大变形后聚合、自反分离、拉伸分离等碰撞结果。研究表明,碰撞参数B≤0.1时,液滴随着We增大出现反弹、大变形后聚合、自反分离等碰撞结果,随着B增大至0.3以上,拉伸分离替代自反分离结果;而当B=0.2时,两种分离均不易发生。此外,随着液滴尺寸由20μm增大至250μm,大变形后聚合区域减小,液滴更倾向出现自反分离或拉伸分离。通过经验公式的拟合,获得了不同尺寸液滴聚合-自反分离、聚合-拉伸分离临界韦伯数预示公式,能够较好地预测液滴碰撞结果。
The condensed Al_(2)O_(3) droplets are extensively existed in solid rocket motor,and their dynamic and collision characteristics can significantly change the two-phase flow loss and specific impulse of the solid rocket motor.In this paper,the volume of fluid method is used to simulate the collision process of condensed Al droplets in a solid rocket motor,which was verified by our experiments.The algorithm is further used to study the collision process of Al_(2)O_(3) droplets,in which the droplet off-center collision process was most concerned.The in⁃fluence of Weber number,collision parameter,droplet size on the droplet collision results was investigated,and collision results including rebound,coalescence after large deformation,reflexive separation,and tensile separa⁃tion were obtained.It is observed that when the collision parameter B≤0.1,rebound,coalescence after large de⁃formation,and reflexive separation results are observed with the increase of We.As B increases above 0.3,ten⁃sile separation occurs instead of reflexive separation.However,when B=0.2,both separations results are difficult to get.In addition,as the droplet size increases from 20μm to 250μm,the coalescence after large deformation region decreases,and the droplet is inclined to exhibit reflexive separation or tensile separation.Finally,through the fitting of empirical formulas,the critical Weber number prediction formulas are obtained for aggregation to re⁃flexive separation and coalescence to stretching separation with various droplet sizes,which are helpful to predict⁃ing the collision results of droplets.
作者
巴燕
胡春波
刘洋
王琢璞
杨文婧
BA Yan;HU Chunbo;LIU Yang;WANG Zhuopu;YANG Wenjing(National Key Laboratory of Solid Rocket Propulsion,School of Astronautics,Northwestern Polytechnical University,Xi’an 710072,China)
出处
《推进技术》
北大核心
2025年第9期122-137,共16页
Journal of Propulsion Technology
基金
国家自然科学基金(51906206)
陕西省自然科学基础研究计划项目(2020JQ-191)
陕西省自由探索类基础研究项目(2024ZY-JCYJ-01-02)。
关键词
固体火箭发动机
两相流
三氧化二铝
偏心碰撞
数值模拟
Solid rocket motor
Two-phase flows
Aluminum oxide
Off-center collision
Numerical simulation
