Which energy source powers the turbine in a turbocharger?

• A. The exhaust gas flowing from the engine.
• B. The intake air stream.
• C. The crankshaft via a belt.
• D. The aircraft battery.

Answer: (A)

The turbine in a turbocharger is powered by the energy of the exhaust gases leaving the engine. As hot, high-velocity exhaust flows through the turbine wheel, it causes the turbine to spin, and that rotational energy is transferred through a shaft to drive the compressor, which pressurizes the incoming air for more fuel in the cylinder and increased power. The intake air stream itself does not drive the turbine; instead it is what gets compressed by the turbine-driven compressor. A belt-connected crankshaft would drive a mechanically driven supercharger, not a turbocharger, and the aircraft battery supplies electrical power for systems rather than turning the turbine.