Simulation and experiment research on vaporizing liquid micro-thruster

Abstract

In the present work, a micro-thruster chip with dimension of 19.5 mm × 9.5 mm was fabricated with MEMS technologies for the experiment study of vaporizing liquid micro-thruster. In addition, a full 3D computational model was constructed to simulate the aft section of a vaporizing liquid micro-thruster for investigating flow characteristics. The results show that there were four distinct flow patterns observed in this study including snake flow, vapor-droplet flow, vapor-droplet-jet flow, and vapor flow. To prevent the failure of micro-thruster chip from generating of snake flow, the heating treatment of an empty micro-thruster chip at 300 °C for 2 h was the key factor. The generation of vapor flow preliminarily proved that the concept of vaporizing liquid micro-thruster chip was feasible. Furthermore, the numerical model in this study successfully provided the thrust estimation. The channel cross-section of 1 mm × 100 μm designed in this study was fit for developing a micro-thruster of O(mN) (ranging from 1 to 6 mN approximately). The numerical simulation could match better with the experiment results for the vapor flow cases if the flow oscillation was taken into consideration, and the heating channel of micro-thruster was lengthened to completely vaporize the liquid water.