S弯进气道旋流畸变数值模拟及特性分析

利用FLUENT软件对S弯进气道旋流畸变进行数值模拟,通过分别对不同攻角、侧滑角飞行状态下的进气道沿程及出口流场进行分析,展现了旋流畸变的产生机理和发展过程。引入旋流评价指标,对旋流畸变进行评定,并与总压畸变评价体系进行对比和分析。研究表明:该S弯进气道出口固有的对涡旋流结构不随攻角变化,但旋流强度随攻角的增大略有减弱;在侧滑状态下,该S弯进气道出口对涡旋流消失,旋流以整体涡出现且强度较大;传统的总压畸变指数无法描述旋流,引入的旋流评价指标能较为准确、直观地评定旋流畸变强度和流场结构。

Numerical Simulation and Characteristic Analysis of Swirl Distortion in S-Duct Inlet

Numerical simulation was carried out to a S-duct inlet by applying FLUENT software.The characteristic and evolutive processes of swirl distortion were revealed by analyzing flow-field in different work conditions.An evaluation criterion for inlet swirl distortion was introduced and applied to analyze results,and compared to total pressure distortion evaluation criterion.Numerical simulation results and analysis show that the connatural twin swirl of S-duct inlet does not change with angle of attack,but the intensity of swirl reduces with angle of attack increasing;in the yawing flight conditions,the bulk swirl comes instead of twin swirl and the intensity is biggish;traditional total pressure evaluation criterion cannot be used to evaluate swirl distortion,by contraries the presented evaluation criterion for swirl distortion is feasible and can be used to evaluate both intensity and structure of inlet swirl distortion.