One in a series of posts about an aeronautical engineering course I created this year.
The aim of this project was to review the physics governing the operation of turbofan engines, as well as begin exploring a few of the many compromises associated with jet engine design and installation. The lecture reviewed the main notions needed in the project in a rather light and illustrative way.
The lecture relies strongly on notions and concepts that I studied together with the class in the previous year, in my course on engineering thermodynamics. Here we work with stagnation (a.k.a. “total”) properties for the first time, and then proceed to aircraft propulsion specifics.
In the last sections of the lecture, I indulge into exploring some of the main parameters and performance indicators of jet engines, as well as the compromises related to their installation.
The notes lack an introductory example that is not extracted directly from a fully-copyrighted book, as well as CC-licensed media to illustrate turbine cooling techniques and principles. I will work on this next year.
Frankly, there is nothing extraordinary here — what you get is your standard third-year overview lecture about propulsion. I simply took pleasure taking the thermodynamics studied in the previous year one step higher. It was a short and comfortable session.
The project was constructed directly with the feedback of the students, who had asked for a more straightforward, lit-up path to a solution. Straightforward it is — three hours of late-night work using any thermodynamics/propulsion manual at hand are enough to crack the project. In this sense it is more of a tutorial exercise than a true project requiring group work and significant initiative. Nevertheless, in order to make progress, one is forced to think carefully about the types of flow within the engine, to translate them into energy equations. A little room for student initiative and exploration is provided right at the end of the project, in the choice of the fan.
The project was successful. With known material, no surprises, no pitfalls, and better marks, we all found an opportunity to breathe, six weeks into the course. I am left with much smaller sense of achievement but I think it is a fair price to pay.