微型涡轮发动机设计与制造的若干关键技术

Key Techniques for Design and Manufacture of Micro Gas Turbine Engine

分析了微型涡轮发动机不同于宏观尺度的流动和燃烧特性(低雷诺数Re、高马赫数M、高库埃特Couette数和低毕渥Biot数的流动,极小空间超高燃烧负荷率的燃烧)。提出了在微尺度和超高转速条件下,传统的流体动力润滑理论所存在的局限性;研究了利用边界滑移实现微尺度条件下气体动力润滑轴承实现超高转速的可能性。基于碳化硅材料在MEMS高温高强度条件下的应用前景,提出将硅基蚀刻与传统的碳化硅反应烧结和磨削加工等工艺进行结合,实现微型涡轮发动机碳化硅材料微细结构的机械加工。

The characteristics of flow and combustion in micro gas turbine engine with the low Reynolds number and the high Mach number, the high Couette number and the low Biot number, as well as the ultra high duty ratio of combustion in very small space are analyzed, which are remarkably distinguished from those on macro scale. At the meantime, the limitation of traditional dynamic lubrication theory at ultra high speed on micro scale is presented, and the possibility of making the gas bearing to be able to work at ultra high speed by utilizing boundary slip is investigated. Due to the applied prospect of silicon carbide in the field of MEMS especially under high temperature and high strength conditions, the technical process of combining silicon etching with reactive sintering and grinding machining of silicon carbide is put forward so that the miniature machining of silicon carbide for micro gas turbine engine becomes possible.