烧蚀环境下的圆柱绕流计算模型  

Numerical models for flow past a cylinder in the ablation environment

作　　者：徐晓亮[1] 黄海明[1] 章梓茂[1] 

机构地区：[1]北京交通大学工程力学研究所,北京100044

出　　处：《空气动力学学报》2011年第2期170-176,共7页Acta Aerodynamica Sinica

基　　金：国家自然科学基金资助项目(10572020)

摘　　要：基于多学科理论建立了高温高压气流环境下圆柱烧蚀、剥蚀的数理模型。利用离散涡方法计算流场与圆柱表面压力分布;采用三方程烧蚀模型计算热化学控制机制下的烧蚀速率,并将其与扩散控制机制下的结果相比较以确定烧蚀量;引入颗粒轨道模型求解剥蚀颗粒的运动。基于该模型对高温高压燃烧室内圆柱形烧蚀试件的绕流场、烧蚀量以及剥蚀颗粒的运动轨迹进行了编程计算分析。研究表明:低雷诺数条件下烧蚀环境对绕流流场的影响不大,而较高雷诺数条件下烧蚀绕流流场与无烧蚀绕流流场的涡街分布存在显著差别;在低雷诺数条件下流场对烧蚀速率的影响甚微,较高雷诺数条件下烧蚀速率略大于无流场烧蚀情况;涡量的存在决定着剥蚀颗粒的运动轨迹与分布,进而影响尾流热场与烧蚀速率。该模型可为热防护材料的烧蚀实验提供参考,并为烧蚀、剥蚀过程的非线性分析提供数据支持。Based on multidisciplinary theory,a numerical model for solving ablation,denudation in a high temperature and high pressure environment is proposed.In this model,the Discrete Vortex Method（DVM） is used in simulate flow field and pressure distribution on the cylinder surface;a common used three-equations model under the thermal-chemical control mechanism is introduced for resolving the ablation loss after comparing with the results under the diffusion control mechanism;furthermore,the denudation loss is simplified by releasing a series particles on the cylinder surface at regular intervals,and a trajectory model is adopted for solving the particles motion.Codes are written and performed well for simulating the flow field,ablation loss and particles motion in a high temperature and high pressure blaster chamber.As results indicated,the flow filed with a lower Re number is basically the same as that in a non-ablation environment,whereas the differences are tremendous when a higher Re number is adopt;with a lower Re number,differences on ablation rate can be neglected whether flow field is considered,whereas the ablation rate is larger when the flow field is considered in a higher Re number;the vortex influenced the particles motion and distribution,which may change both the temperature distribution in the wake and the ablation rate on the cylinder surface;This model may offer numerical references to ablation experiments on thermal protection materials and prepare relative data for nonlinear analysis.

关 键 词：烧蚀 剥蚀 两相流 离散涡方法 

分 类 号：O359.1[理学—流体力学]