Gas Jet Executive Body Dynamic Performance Analysis

Actuator is the component of guidance ammunition which is used to produce control andto change flight path and posture. Guidance ammunition can gain control by changing airpower, namely the aerodynamic control, also by loading directly control, namely direct forcecontrol. One of significant advantages of Direct force control is that ic can be used in thinatmosphere . According to the different function forms, they can be divided into three kinds:steering engine control, such as electricity-actuated, fluid-actuated and air-actuated, thrustvector control and direct force control. The paper researches on the Gas jet actuator, whichbelongs to the direct force control.Nozzle is the part generating thrust , at the same it can maintain gas generator pressure.Inthis paper, the flow loss of nozzle is discussed; thrust calculation formula is deduced;analyzed,and through calculating the nozzle about the known structure, the best expansionratio and expansion half angle are obtained.The mechanical characteristics of paddle and the motion characteristics of slide areobtained through analyzing the internal actuators. The suction formula of electromagnets andthe time response are discussed, then the iteration method of electromagnetic suctioncalculation is put forward.The paper analyzes the airflow state in pipeline of actuator and verifies the feasibility ofthe calculation method of one-dimensional unsteady flows. It proposes numerical calculationmethod of one-dimensional unsteady flows based on characteristic line theory, determines theboundary conditions based on the assumption that throttling mouth has the same entropy.Dynamic calculation of actuator system is done and dynamic change of each parameter isobtained through combining the dynamics calculation, the electromagnetic force calculationof electromagnet with pipeline flow calculation. Based on this, the response time of thesystem is calculated.Analyzed the various parameters on the influence of system response time,and bycomparison, the degree of the size of parameters is obtained. Using theoretical within the ballistics , interior ballistic process and calculation method ofgas generator are geted, and according to strength theory , shell thickness and threadedconnections are designed.