Study on flow regulation characteristics of fuel feeding systems for powder engines

Changing the mass flow rate of powder propellant with high precision and large range is essential and challenging for adjusting thrust of the powder engine. In this paper, the regulation characteristics of the powder flow rate are investigated by adjusting two gases, namely driving gas and regulating gas. Firstly, the effect of driving gas on powder flow are analyzed, which provides the large ranged flow regulation with the adjustment rate of 2.39 and high precision with resolution ratio of 0.8 g/s. The powder flow rate is successfully predicted based on the Bernoulli equation, not only with an less deviation of 4.73%, but also more conducive to development of the lightweight system. Second, the introduction of regulating gas provides a new method for powder flow regulation. The powder flow rate can achieve a regulation rate of 1.36 with a small amount of regulating gas. The linear relationship between powder flow rate and regulating gas fraction is established to enable its prediction. Finally, the regulation logic is proposed, based on which the flow rate can be increased or decreased by adjusting the quantities of these two gases flexibly. This study can provide a reference for the thrust regulation of powder engines.