具有瞬变失速流态的亚音速扩压器性能预测方法

A PREDICTION METHOD FOR TRANSITORY STALL FLOWS OF SUBSONIC DIFFUSER

关键词:  亚音速进气道  紊流边界层  计算  预测

Key words:  Subsonic inlet  Turbulent boundary layer  Computation  Prediction

摘要:

本文介绍了文献[4]所提出的一种具有瞬变失速流态的二元亚音速扩压器性能预测方法,介绍了一个新的摩擦系数关系式和一个新的渗混率公式,可用于扩压器内具有较大失速区的计算.本方法同时也适用于无失速及完全失速流态的计算,因此大大扩充了文献[3]的应用范围.计算结果与本文作者所做的实验数据相比较后得出:对大展弦比的二元扩压器,C_p值计算误差在2θ≤20°时约为1%,当2θ>20°时,其C_p计算值误差将随2θ的增加而增大.而对小展弦比二元扩压器由于两底壁附面层的影响,C_p计算值约高于实验值4%.本文对文献[4]所提出的方法作出评估.

Abstract:

A prediction method is presented to computate the performance of two-dimensional subsonic diffusers.The present method gives accurate prediction in three flow regimes unstalled flow, transitory stall, and fully developed stall. Improved correlations of flow detachment and a new correlation for skin friction and two new correlations for the entraining rate in turbulent boundary layers are presented.Experimental data from the papers [8, 10] are compared to the computational results of the prediction method showing that the agreement is quite well at 2θ= 6°-24°. After 2θ>20° the difference between the theoretical results and experimental data increases with θ.