For the 2016-17 year, one of YUAA’s projects will be to research, design, build, test and optimize a small centrifugal flow turbojet engine capable of a sustained combustion, complete with built-in starters, sensors, fuel supply system and thrust measuring equipment. YUAA has never built a turbojet engine before, so both the team leader Kevin Liang ’19 and YUAA members are very excited to move ahead with the project.
Old-style airplane engines are piston-propeller internal combustion engines that, while able to provide sufficient thrust for low speed, low altitude cruising, fail to support ever-increasing demand on airplane’s performance. Such a demand for engines with higher thrust to weight ratio and less structural complexity was eventually met with the arrival of jet engines.
The very first generation of jet engines (and the simplest of which) is the turbojet, in which air is forced through a series of axial or centrifugal flow compressor stages to gain enough pressure and temperature before being mixed with fuel and ignited. The heated flow of high pressure exhaust will then go through stages of turbines (which could be thought of as the compressor blades reversed) to extract a fraction of the energy to drive the compressors before being ejected rearward to produce thrust. In this way, the turbojet can produce very high thrust at very low resistance, bulk weight, and high rpm.
For the past few months, members have been working on designing and constructing the engine. Since this project is both challenging and new to YUAA, Turbojet members will learn skills and gain experience that will prove invaluable for not only YUAA, but the wider aerospace community as well. Members have put their hands on welding and machining, putting the product closer to its final shape.
As of March 2017, The team is wrapping up the machining part of building this engine, with the help of Mr. Nicholas Bernardo in the student machine shop of Yale School of Engineering and Applied Science. The next step would be welding the combustion chamber, and final assembly. Welding was completed by Trevor Chan ’20 under the help of Mr. David W. Johnson at Yale’s Wright Laboratory in early April, and final assembly was commenced shortly after. During the week of April 17, 2017, the engine core was mounted onto the engine frame, with other components soon mounted and secured. With some more finishing touches, the jet engine will be ready for its test run.