Effect of Some Disturbance Factors on the Motion Stability of Unguided Rockets

Abstract

A mathematical model of unguided-rockets’ motion in the air taking into account the deflection of the thrust and the position deviation of the center of gravity has been established. The mathematical model has been solved for a specific unguided-rocket slow spin to predict its standard trajectory and deviation trajectories; calculated results agree well with the corresponding data in the firing table. The effect of the disturbance factors on the motion stability is shown through the deviation of the graph of the angle of attack; sideslip angle and the trajectory falling points compared to the corresponding values of the standard trajectory, which does not contain deviations.

Effect of some Disturbance Factors on Falling Point Distribution of Unguided Rocket

“…According to [1], characteristic parameters of CG offset and thrust misalignment in the body coordinate system are shown in Fig. 4.…”

“…These points characterize the disturbance factors at the initial time and they are called feature points. When adding PAIs misalignment, the mathematical model in [1] is developed into a new model, which is the mathematical model of rocket motion taking into account thrust misalignment, CG offset, and PAIs misalignment. From [1], Eqs (2) and ( 3), the mathematical model is rewritten as follows:…”

“…The obtained results can be applied to other rockets of this type. The ballistic parameters and aerodynamic coefficients are taken from [1,3]. The results of solving the mathe-matical model show the dependence of the falling point deviation on the disturbance factors which are presented in the following sections.…”

“…The effect of thrust misalignment and CG offset on rocket motion in the air is investigated in [1]. However, [1] mainly focuses on the mathematical model building and solving the model only in a narrow range of disturbance parameters. Therefore, the obtained results about the effect are incomplete and meagre.…”

“…In this paper, the mathematical model in [1] is developed to supplement the effect of PAIs misalignment on the rocket motion. In addition, the new model is solved more fully when investigating the entire variable range of the disturbance parameters.…”