论文部分内容阅读
本文建立了计算塞式喷管流场的物理数学模型，通过求解采用Ｋ－ε紊流模型的二维Ｎ－Ｓ方程组， 发展了相应的数值计算方法， 对在不同环境压强下某塞式喷管的流场进行了数值模拟。数值模拟的结果表明： 塞式喷管扩张段的膨胀过程能够自动适应环境压强的变化； 环境压强由高变低时， 回流区由开式结构变成闭式结构， 形成闭式结构时， 塞锥底部压强近似于常数， 受环境压强影响不大； 塞式喷管的塞锥长度减小到一定程度后， 塞锥长度对流场结构影响不大。
In this paper, a physical mathematic model for calculating the flow field of a plug nozzle was established. By solving the two-dimensional N-S equations using the K-ε turbulence model, a corresponding numerical method was developed. The nozzle flow field is numerically simulated. The results of numerical simulation show that the expansion process of plug nozzle can automatically adapt to the change of ambient pressure. When the ambient pressure changes from high to low, the recirculation zone changes from open structure to closed structure. When closed structure is formed, The pressure at the bottom of the cone is approximately constant, which is not significantly affected by the ambient pressure. After the length of the plug nozzle decreases to a certain extent, the length of the plug cone has little effect on the structure of the flow field.