双轴承旋转喷管型面设计及数值模拟研究

Geometric design and numerical simulation study of two bearing swivel nozzle

针对短距/垂直起降战斗机高机动飞行的迫切需求及其矢量喷管机械结构复杂笨重的问题,提出了基于轴对称双喉道气动矢量喷管设计的双轴承旋转喷管,通过采用双轴承结构和双喉道气动矢量喷管相结合的方式,减少驱动结构,使喷管能更高效、轻便地实现短距/垂直起降,并且赋予了飞行器平飞模态高机动飞行的潜力。基于典型轴对称双喉道气动矢量喷管构型,开展了双轴承旋转喷管的型面设计和运动规律研究,利用数值模拟开展关键设计参数对喷管流场的影响研究,获得喷管的性能变化规律。结果表明,短距/垂直起降模态下,典型构型的双轴承旋转喷管推力矢量角最大可达108°,满足短距/垂直起降飞行器对喷管的要求。凹腔段的长短轴比值对喷管短距/垂直起降模态的性能影响较大,相同落压比条件下,长短轴比值越大,喷管的总推力系数越低,推力矢量角越大,并且推力矢量角最大差值达到41°。本文所提出的双轴承旋转喷管可为未来具备短距/垂直起降、高机动性能的飞行器动力系统提供一种新的解决方案。

Aiming at the need for high maneuver of Short/Vertical Takeoff or Landing(S/VTOL)aircraft fighter,to reduce the complex and bulky mechanical structure of thrust vectoring nozzle,the design of two bear⁃ing swivel nozzle(2BSN)based on axisymmetric dual throat fluidic thrust vectoring nozzle was proposed.2BSN combined a two-bearing structure with dual throat fluidic thrust vectoring nozzle.This design can reduce actua⁃tors,efficiently realize the function of short/vertical takeoff or landing,and it gives the aircraft with the potential for high maneuverability in normal flight mode.Based on the basic configuration of axisymmetric dual throat fluid⁃ic thrust vectoring nozzle,the design and motion law of 2BSN were investigated.The influence of key design pa⁃rameters on the nozzle flow field was studied with numerical simulation methods,and the performance changes of the nozzle were obtained.The results show that the maximum thrust vectoring angle of 2BSN can reach 108°in S/VTOL mode,which satisfies the demand of S/VTOL aircraft.The ratio of major and minor axes of nozzle cavity has a great influence on S/VTOL performance of the nozzle.In the same nozzle pressure ratio conditions,the larg⁃er ratio of major and minor axes leads to the larger thrust vectoring angle and smaller total thrust coefficient.The maximum difference of thrust vectoring angle reaches 41°.2BSN proposed in this paper can provide a new solu⁃tion for the future high maneuverability and S/VTOL aircraft power system.