关节间隙对矢量喷管调节机构动态特性影响的数值仿真与验证

Numerical Simulation and Verification of the Influence of Joint Clearance on Dynamic Characteristics of Thrust-vectoring Nozzle Adjusting Mechanism

为研究飞机在不同飞行工况下关节间隙对矢量喷管运动调节机构动态特性的影响,采用第1类拉格朗日方程与混合接触力模型和LuGre摩擦模型相结合的方法,构建了考虑关节间隙和摩擦系数等特征的矢量喷管运动调节机构单叶动力学理论模型,进而构建了整体调节机构的运动学分析模型。结果表明:由于关节间隙的存在,在矢量喷管运动调节机构运动状态突然改变时,初始碰撞阶段调节片的位移几乎不受间隙碰撞的影响,但速度与加速度会产生剧烈且短暂的振动,振动大小受关节间隙影响较大,而间隙对平稳运动时的调节片运动精度几乎不产生影响;整机矢量喷管运动调节机构做收扩运动时,各关节产生的碰撞力几乎相同,做上下偏转运动时,C关节处产生的碰撞力最大,A关节处的受力次之,B和D关节处的受力最小。

In order to study the influence of the joint clearance on the dynamic characteristics of the thrust-vectoring nozzle adjusting mechanism under different flight conditions,an single blade dynamic model of the thrust-vectoring nozzle motion adjusting mechanism considering the characteristics of joint clearance and friction coefficient was built by using the method of combining the first type Lagrange equation with the mixed contact force model and the LuGre friction model,and then the kinematic analysis model of the overall adjusting mechanism was established.The results show that due to the presence of joint clearance,if the motion state of the nozzle adjusting mechanism undergoes abrupt changes,the displacement of the nozzle flap in the initial impact stage is almost not affected by the clearance impact,but the velocity and acceleration of the flap will oscillate violently and momentarily,and the oscillating amplitude is greatly affected by the joint clearance,while the clearance has little effect on the motion accuracy of the flap during the stable motion.When the thrust-vectoring nozzle adjusting mechanism of the whole engine performs the converging and diverging motion,the impact force generated by each joint is almost the same.While performing the up and down deflection motion,the generated impact force is the largest at joint C,followed by joint A,and the impact force at joints B and D is the smallest.