InjectorImpinging Typeby Various (engine-specific)
Typical Specifications
Orifice Count
100u20136,000+ per injector face
Orifice Diameter
0.3u20133.0 mm
Pressure Drop
15u201330% of chamber pressure
Operating Principle
Propellant streams are directed through precision orifices at calculated angles so that fuel and oxidizer jets physically collide (impinge), breaking into fine droplets that mix and vaporize rapidly for efficient combustion.
Impinging injectors are the most common type of rocket engine injector, using hundreds or thousands of small orifices arranged to create streams of fuel and oxidizer that collide and atomize. Various configurations include unlike-doublet, like-on-like, and triplet patterns. This design was used in the F-1, RS-27, and many other classic engines.
Materials
Used In Engines
Common Failure Modes
Combustion instability (screech, chugging), injector face erosion, orifice blockage, thermal erosion of face plate, manufacturing defects in orifice geometry
Recent Innovations
Baffles and acoustic cavities for stability (F-1), platelet manufacturing for precision, self-facing cooling with film barrier
