Innovative Jet Pump Ice Protection System for A400M 2015-01-2136
A system has been designed for the A400M wherein engine air intake ice protection is provided by hot air bled from the engine cooled by air from inside the nacelle with a jet pump.
Two variants of the system were developed. The first had an active temperature and pressure control downstream of the jet pump, and the second was without temperature control.
Maximum temperature was a constraint for the design of the system since the engine air intake is manufactured in aluminum. In addition, several other constraints appeared during the detailed design of the system;
the tight space allocation inside the nacelle limited the length of the jet pump,
the low temperature provided by the engine bleed in flight idle limited the secondary flow used to cool the engine bleed, and
the complex air distribution needed to supply air to the intake areas.
The design, validation and verification of the system went through several stages;
analyses,
hot air mass flow validation testing of the intake in icing tunnel,
testing of the ice protection system, intake and engine all together in an Altitude Test Facility and,
testing in the aircraft natural icing flight test campaign
All of them were used to show compliance with EASA CS-25 regulation.
