Dynamic characteristic of thrust-vectoring nozzle adjusting mechanism considering clearance of motion joint

Abstract

An essential device for managing the vectoring nozzle’s thrust direction is the thrust-vectoring nozzle adjusting mechanism. The attitude of an aircraft’s flight may be changed by adjusting the vectoring nozzle’s airflow, which affects the direction of thrust. The adjusting mechanism’s motion precision and operational stability are crucial in this procedure. In this paper, the influence of the clearance of the motion joint on the dynamic characteristics of the thrust-vectoring nozzle adjusting mechanism under different flight conditions are studied. First, a dynamic model of the thrust-vectoring nozzle adjusting mechanism that takes into account the clearance and friction properties of the motion joint is constructed by combining the Lagrange equation of the first sort with the mixed contact force model and the LuGre friction model. Second, the variation law of nonlinear contact stiffness is explored, and the precision of the dynamic model is confirmed by contrasting the results of the numerical simulation with those of the Simulink simulation. Finally, the simulation results reveal that while the motion joint’s clearance causes the adjusting blade’s velocity and acceleration to vibrate violently and momentarily during early operation, this clearance has minimal effect on the precision of blade motion throughout the stable phase.