ELI5: Explain Like I'm 5

Thrust specific fuel consumption

Ok kiddo, let me explain thrust specific fuel consumption (TSFC) to you in a way that's easy to understand.

Imagine you're holding a big heavy suitcase and you need to move it from one place to another. You have two options: you can either walk slowly, taking small steps and using less energy or run as fast as you can, using more energy, but getting there faster. Similarly, when an airplane or rocket engine generates thrust, it needs to burn fuel to move forward.

The amount of fuel burned by an engine to produce a certain amount of thrust is measured by its thrust specific fuel consumption. It's like how much food or energy you need to eat to move the heavy suitcase a certain distance. If an engine has a low TSFC, it uses less fuel to produce the same amount of thrust, just like how walking slowly and taking small steps uses less energy.

On the other hand, if an engine has a high TSFC, it uses more fuel to produce the same amount of thrust, just like how running as fast as you can uses more energy. So, the lower the TSFC, the more efficient the engine is, and the longer it can fly or travel on a given amount of fuel.

In other words, TSFC is like a measure of how much fuel an engine needs to produce a certain amount of power, just like how you need to eat more food to run faster for a longer time. Got it?