喷嘴动态特性的好坏，对液体火箭发动机燃烧稳定性具有重要意义。但由于缺乏高效的外部周期性脉动流量发生器，特别是在高反压环境下，引起管路来流较强振幅的压力、流量脉动变得更加困难。为解决上述问题，研制了利用惯性驱动可在高反压环境下产生强正弦信号的脉动流量发生器，在高反压环境下可激起高达15%以上的压力振幅；通过采用电导法测量离心喷嘴液膜厚度，从而获得脉动流量，分别在反压为0.5、1.0和1.5 MPa的环境下对其不同脉动频率下的动态特性进行实验研究，研究表明：反压的增加对离心喷嘴流量脉动具有抑制作用。对连续的喷雾图像进行互相关处理得到其不同反压环境下的脉动速度场，结果表明：随着环境压力的升高，其喷雾场速度传递函数振幅呈下降趋势，与反压对喷嘴传递函数的影响规律一致。

The dynamic characteristics of nozzles are of critical significance to the combustion stability of liquid rocket engines. However， the lack of efficient external periodic flow pulsator， particularly in the environment of high back pressure， increases the difficulty in generating pressure and flow pulsation with strong amplitude of pipeline incoming flow. To solve these problems， a flow pulsator is developed using inertia drive to generate strong sinusoidal signals which can generate pressure amplitude up to 15% in a high back pressure environment. The flow pulsation was obtained by measuring the liquid film thickness of the swirl injector with the conductance method. The dynamic characteristics of the swirl injector at different pulsation frequencies were experimentally studied under the conditions of 0.5， 1.0 and 1.5 MPa， respectively. The results show that the increase of the back pressure has an inhibitory effect on the flow pulsation of the swirl injector. The pulsating velocity fields in different back pressure environments were obtained by cross-correlation processing of continuous spray images， and the results reveal a decreasing trend of the amplitude of the spray velocity transfer function with the increase of ambient pressure， consistent with the influence rule of back pressure on the nozzle transfer function.