Definition
In a continuous-flow fuel injection system, discharge nozzles are small fixed outlets located in each cylinder's intake port that spray metered fuel continuously into the incoming air just before it enters the cylinder. There is one nozzle per cylinder, and each is calibrated to deliver fuel at a steady rate matched to engine demand.
Plain English
Small spray outlets, one per cylinder, that release fuel into the air on its way into each cylinder. They run continuously while the engine is operating, not in pulses.
Context Anchor
Seen in induction system and carburetor discussions, especially when explaining how fuel is added to intake air before combustion.
Derivation
"Discharge" comes from the Latin discarricare, meaning to unload or release. "Nozzle" is a small spout or outlet. Together the term simply names a fitting that releases fuel — useful because it tells you the part's job rather than its shape.
Why Pilots Care
Proper function ensures correct fuel-air mixture; clogged nozzles can lead to rough running or power loss.
Intuition Check
Do not read discharge as an electrical spark or as exhaust leaving the engine. Here, discharge means fuel being released from a small outlet into the air moving through the carburetor.
Example Sentence 1
During the run-up, a fouled discharge nozzle on the number three cylinder caused a slight roughness that smoothed out after a lean-of-peak burn-off procedure.
Example Sentence 2
A blocked discharge nozzle can cause the engine to run unevenly during flight.