01 Inverse solver Gas-path analysis

Work backwards from what you can measure.

The console answers "given these efficiencies, what thrust do I get?". On a real engine the arrow points the other way: you can measure thrust, fuel flow and a few gas-path temperatures, but not the compressor's efficiency — and that is the number that tells you whether the engine is healthy. This solves the second from the first.

CONCEPT · WHY THE ANSWER NEEDS AN ERROR BAR
An inverse problem will happily hand back a perfect-looking fit that means nothing. Solve for more unknowns than you have measurements and infinitely many answers fit exactly. Even with enough measurements, two parameters can act on the observables almost identically — compressor and turbine efficiency both mostly show up as thrust and fuel flow — so the fit trades one against the other freely. Every result below carries its uncertainty and a verdict on whether it is actually pinned down.

The problem

Flight condition & known inputs

Anything you solve for below starts from these values; anything you do not solve for stays pinned at them. A wrong fixed input biases the answer.

What you measured
What to solve for

Recovered condition

Enter what you measured, choose what to solve for, and press Solve. Or load the worked example: it runs the forward model on a known engine, hands the solver only the observable outputs, and shows whether the hidden values come back.