Turbojets: Thermodynamics for Mechanical Engineers

Turbojets allow us to create the thrust an airplane needs to fly. A Brayton cycle engine lies at the heart of a turbojet, but it’s sandwiched between a diffuser and a nozzle. These new components allow us to convert kinetic energy to enthalpy (or vice versa). This video will show you a systematic process you can use to solve any turbojet problem! In this example, you’ll learn how to solve a turbojet problem using variable and specific heat analysis. I think the trickiest parts of this analysis are (i) converting between moving and stationary frames of reference, (ii) units on the kinetic energy terms in metric and imperial questions, and (iii) remembering that the back work ratio of the Brayton cycle here is limited to 1 so that we can maximize the velocity at the exit of the nozzle.