摘要
电弧加热器流场特性是影响材料热化学烧蚀的关键因素之一,根据可压缩的轴对称N-S方程,对喷嘴的超声速自由射流、垂直冲击射流进行了数值模拟,采用k-ε湍流模型.计算得到自由射流流场结构的三个区域:射流核心区、射流卷吸区和射流湍流区,射流的速度分布具有不均匀性,其轴线射流速度存在较大变动;冲击射流近壁处存在着滞止区.所获得的喷嘴外部流场的流动状况以及冲击射流参数分布,如压力、温度和速度分布,可用于烧蚀试验和计算优化设计,流场计算结果与烧蚀实验值吻合.
The fluid dynamics in the jet field of AC arc heater is one of the key factors to material thermochemical ablation. Ultrasonic free and impinging jet were predicted by compressible N - S equation, the FEM and k - 8 turbulence model were employed in the calculation, the free jet field could be characterized by three regions ： the core region, the entrainment region, and the fully turbulent region, the velocity distribution of the free jet is non -homogeneous, and the axis velocity is fluctuated; stagnation region can be seen near the wall for impinging jet; it is useful in understanding nozzle external flow field and impinging jet parameter distribution such as pressure, temperature, and velocity. It is also helpful optimal design of experimental set and calculation of the ablation, the numerical results are in good agreement with experimental data.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2007年第4期579-581,585,共4页
Materials Science and Technology
基金
湖南省自然科学基金资助项目(98JJY2028和03JJY3132)
湖南省教育厅青年项目资助项目(02B037)
