Definition
In a turbine engine, the turbine wheel located directly behind the combustion section whose sole job is to extract energy from the hot, expanding combustion gases and use that energy to drive the engine's compressor through a connecting shaft.
Plain English
A bladed wheel spun by hot gases coming out of the burner. As it spins, it turns a shaft that drives the compressor at the front of the engine, which keeps fresh air flowing in.
Context Anchor
Seen in turbine-engine heat management, especially when discussing engine temperature limits and how heat affects the parts that keep the engine running.
Derivation
"Turbine" comes from the Latin turbo, meaning a spinning thing or whirlwind. The name "compressor turbine" simply tells you which job this particular turbine does -- it powers the compressor (as opposed to a power turbine, which drives the propeller or output shaft).
Why Pilots Care
It directly affects engine power output, fuel efficiency, and temperature limits that must be monitored during all phases of flight.
Intuition Check
Do not read compressor turbine as “a turbine that compresses air directly.” It is the turbine that drives the compressor; the compressor is the part that actually compresses the air.
Example Sentence 1
During start, the pilot monitored ITT closely to avoid overheating the compressor turbine blades.
Example Sentence 2
A failure in the compressor turbine would immediately reduce engine thrust and require an emergency landing.