微推力与冲击力关系的实验研究

微型推进器固定在测试台架上进行微推力的直接测量,常会受到推进器工质导管等引线的干扰而造成较大的测量误差,甚至无法测量。为此提出用推进器喷嘴对准测力探头喷射,通过测量冲击力来间接获得微推力的思路,研究了微型冷气推进器产生的冲击力与微推力之间的关系。发现采用冲击力测量时,只要测力探头面积足够大,冲击力随着喷嘴与测力探头之间距离变化的曲线会出现一个高平台区,在此区域内所测得的冲击力大小变化不大,而且与真正微推力的大小几乎相等。

Experimental investigation on the relation between micro-thrust and impinging force

If micro-thrust is measured directly by mounting the micro-thruster on the test stand,the fluid supplying pipes,power cords,thermocouple wires and so on,which connect the thruster with equipments outside the test stand,often disturb micro-thrust test signal severely and cause large error,even failure.To overcome this problem,it is proposed to test the impinging force produced by the jet from the micro-cold gas thruster impinging on the test probe,instead of testing the thrust force directly and study the relation between impinging and real thrust forces.It is found that if the test probe area is large enough,the profile of the impinging force with respect to the distance between the nozzle and the test probe will turn out a plateau area.The impinging force within the plateau area changes little and is almost equal to the real thrust force.