In an exhaust driven supercharger (turbocharger), the turbine is coupled to and drives a ______.

• A. centrifugal compressor.
• B. piston-type compressor.
• C. radial piston pump.
• D. diaphragm pump.

Answer: (A)

The turbine in a turbocharger is tied directly to the compressor on the same shaft, so exhaust energy that drives the turbine ends up spinning the compressor itself. The type of compressor used in this arrangement is a centrifugal compressor, which uses a rapidly rotating impeller to draw in air and fling it outward into a diffuser or scroll to raise its pressure. This setup is ideal for turbocharging because it can provide high flow and high pressure at the very high rotational speeds produced by the turbine, all in a compact form.

Other options don’t fit because piston-type compressors or pumps rely on reciprocating motion and are not suited to the high-speed, continuous operation of a turbocharger. Diaphragm pumps are small, low-flow devices used for different purposes, not for delivering the large volumes of compressed intake air required by an aircraft engine.