Follow the exhaust. See how hot gas powers a turbine in both engines.
Both use hot gas to turn a turbine, then a shaft to power a compressor. Follow the orange gas through each highlighted turbine and the green shaft back to the compressor.
Combustor → turbine → nozzle
Hot gas gives up some energy to drive the compressor through the turbine shaft. Gas leaving the turbine still has energy to accelerate through the nozzle.
A fan adds an outer stream that goes around the hot core. The core and bypass streams both produce thrust. A separate turbine drives the fan.
Cylinder → turbo turbine → exhaust pipe
The gas has already pushed the piston. Some of its remaining energy turns the turbo turbine, whose shaft powers the intake compressor. The gas then leaves through the exhaust system.
Rotating blades squeeze incoming air. The turbine supplies the power through a shared shaft.
Higher-pressure air enters the combustor, where fuel is added and burned.
In both engines, hot gas turns a turbine. Its shaft transfers that energy to a compressor.
The shared idea is to extract energy from hot gas and turn it into shaft power. The difference is what the gas has already done, and what it does next.
| Follow the energy | Jet engine · basic turbojet | Turbocharged car |
|---|---|---|
| Before the turbine | Fuel burns in the combustor, adding energy to compressed air. | Burning fuel produces gas that has already expanded against the piston and turned the crankshaft. |
| What the turbine does | Hot gas expands through the blades and turns the rotor, giving up some energy. | Exhaust expands through the turbo turbine and turns its rotor, giving up some remaining energy. |
| Where turbine power goes | A shaft drives the compressor at the front of the engine. | The turbo shaft drives the intake compressor. It is separate from the engine's crankshaft. |
| After the turbine | Gas expands and accelerates through the nozzle into a fast rearward jet. | Gas continues through the exhaust system and leaves the tailpipe. |
| How this helps propulsion | Exhaust produces thrust. Accelerating gas backward pushes the engine forward. | Exhaust powers intake boost. More fresh air allows more fuel to burn. Pistons and the crankshaft supply power to the wheels. |
With turbofan bypass enabled: hot core gas also powers a turbine connected to the fan. The fan accelerates air around the core, adding thrust. That bypass air does not pass through the combustor.
Separate gas paths, a shared shaft: the car turbo transfers energy from exhaust to fresh intake air through its shaft. The two gas streams use separate passages. Tailpipe thrust is not the car's main source of propulsion.
These are simplified teaching cutaways, shown in slow motion. Dots trace gas paths; their spacing and speed are not measurements of pressure, temperature, or flow. Green shafts show mechanical power, not gas passages.
Power demand changes an illustrative operating state. Both rotors respond gradually. Car boost lags a change in demand because the turbo needs time to speed up. The response bars are normalized within each engine; they are not comparable performance measurements. Their time constants are animation choices.
Slow motion changes playback speed only. Pause freezes both the mechanism and its response. Selecting a stroke pauses at that stroke's midpoint. The car is a four-stroke petrol engine: intake, compression, power, exhaust over two crankshaft revolutions (720°). The simplified valve timing omits overlap; a real engine's timing and ignition vary.
The turbo and crankshaft rotate independently. The intercooler removes heat from compressed intake air. In the jet, combustion stays continuous and all stages operate together. The optional turbofan view schematically shows a separate fan turbine and shaft; blade counts and geometry are illustrative.
Original interactive illustrations. No measured engine data or performance prediction.