摘要
从共轴式直升机双旋翼系统的实际结构布局出发,建立上、下旋翼桨叶载荷校准试验力学模型,选择非翼型的桨叶根部段作为桨叶测量剖面进行应变桥路设计,通过单向加载法的桨叶载荷校准试验获得上、下旋翼桨叶载荷方程。提出一种共轴双旋翼载荷测量方案,并据此研制基于小遥测应变测量技术的机载测试系统应用于外场试飞测试。真实大气环境下飞行实测的共轴双旋翼桨叶挥舞弯矩的分析表明:上、下桨叶的挥舞弯矩随时间呈现周期性变化,并且出现正、负脉冲对应现象;平飞状态上、下桨叶的挥舞弯矩相差不大,而悬停状态差别明显;对下旋翼桨叶挥舞弯矩交变量要予以特别关注。文中使用的小遥测应变测量技术已经在某型共轴式直升机飞行试验中成功应用,所测量的双旋翼桨叶结构载荷对共轴式直升机研究工作意义重大。
Based on the actual structure of twin-rotor layout of a coaxial helicopter,the mechanical model of the blade load calibration test for the upper and lower rotors of a coaxial helicopter is set up,and the strain gauge is modified at the blade root section of non-airfoil,and the relation equation regarding the strain-output of electricalbridge versus the load-input for individual blade of the upper and lower rotors of a coaxial helicopter is established through the blade load calibration test using single loading method.The measurement solution for twin-rotor blade structural load of a coaxial helicopter is presented,and an airborne strain testing system based on short distance wireless telemetry is developed and applied to measure twin-rotor blade structural load of a coaxial helicopter during the flight tests.The coaxial helicopter flight tests were implemented in atmospheric environment,and the flight test data of the blade structural load of coaxial rotors are obtained and analyzed.The analysis of the flight test data shows that the flapping moments of upper and lower blades change periodically with time,and the corresponding phenomena of positive and negative impulses are found.The flapping moments of upper and lower blades are not much different in flat flight,but obviously different in hovering.Special attention should be paid to the alternating values of the blade flapping moment on the lower rotors.The strain measuring technique based on short distance wireless telemetry in this paper has been successfully applied to a coaxial helicopter flight tests,the measured structural loads of twin rotor blades are of great significance to the research of coaxial helicopters.
作者
程卫真
Cheng Weizhen(Aircraft Flight Test Technology Institute,Chinese Flight Test Establishment,710089,Xi’an,China)
出处
《应用力学学报》
CAS
CSCD
北大核心
2019年第5期1005-1011,1253-1254,共8页
Chinese Journal of Applied Mechanics
关键词
共轴式直升机
双旋翼
桨叶
结构载荷
试飞技术
小遥测应变测量技术
coaxial helicopter
twin-rotor
blade
structural load
flight test technique
strain measuring technique based on short distance wireless telemetry