轴对称型面喷管推力计算方法

为分析喷管内流场的变化，使用 1 维计算模型和基于 FLUENT 的 2 维计算模型对轴对称型面喷管的推力进行计算，分析 2 种计算结果的差异。利用正交设计法，研究喷管的燃烧室压强、扩张角、扩张比、扩张段长度以及燃气射流的黏度对喷管推力计算的影响。结果表明：推力差异与燃烧室压强近似线性关系；推力差异随着燃气黏度的增加而增大；当初始扩张角越大、出口扩张角越小时，推力差异越小；推力差异随着扩张比、扩张段长度与喉部半径比的增加先减小后增加；在低压、低黏度的情况下，1 维计算方法可用于喷管推力的计算，否则，2 维计算方法更适合。

Calculation Method for Thrust of Axisymmetric Profile Nozzle

In order to analyze the change of flow field in the nozzle, the thrust of the axisymmetric nozzle is calculatedusing the 1-dimensional calculation model and the 2-dimensional calculation model based on FLUENT, and the differencebetween the 2 calculation results is analyzed. The effects of pressure, expansion angle, expansion ratio, length of expansionsection and viscosity of gas jet on the calculation of nozzle thrust are studied by orthogonal design method. The resultsshow that the thrust difference has a linear relationship with the combustion chamber pressure. The difference of thrustincreases with the increase of gas viscosity. When the initial expansion angle is larger and the exit expansion angle issmaller, the difference in thrust is smaller. The difference of thrust decreases first and then increases with the increase ofthe expansion ratio, the length of the expansion section and the radius of the throat. In the case of low pressure and lowviscosity, the 1-dimensional calculation method can be used to calculate the nozzle thrust. Otherwise, the 2-dimensionalcalculation method is more suitable.