Definition 1 of 2
Definition
The pressure of the exhaust gases measured at the rear of the turbine section of a turbine engine, after the gases have passed through and given up energy to the turbine wheels. It is one of the two pressure values used to calculate Engine Pressure Ratio (EPR), where it serves as the outlet pressure compared against the engine inlet pressure.
Plain English
The pressure of the air and exhaust gases at the back end of the turbine, just after they have spun the turbine blades. It tells you how hard the engine is pushing gas out the back compared to what came in the front.
Context Anchor
Seen in turbine engine instrument discussions, especially when explaining how engine pressure ratio is measured.
Derivation
Turbine comes from the Latin turbo, meaning a spinning thing or whirlwind. Discharge means to release or let out. So turbine discharge pressure is literally the pressure of what is being let out from the spinning section of the engine.
Why Pilots Care
It provides a direct measure of engine output used to confirm proper thrust and detect turbine problems.
Intuition Check
Do not read discharge as paperwork, an electrical spark, or simply dumping something. Here, discharge means the outlet flow leaving the turbine section.
Example Sentence 1
The EPR gauge compares engine inlet pressure to turbine discharge pressure to give the pilot a direct indication of thrust.
Example Sentence 2
A sudden drop in turbine discharge pressure warned of a possible turbine failure.