Icing Qualification Wind Tunnel Test of Helicopter Engine with Inlet Barrier Filter Air Intake

Abstract

Icing wind tunnel testing was performed as part of the Republic of Korea certification of the Light Civil Helicopter (LCH) for inadvertent flight in icing conditions. The test was aimed at the compliance demonstration of the engine and air intake with dry-media Inlet Barrier Filter (IBF) and was performed with an Arriel 2C2 engine in turbojet configuration. Testing took place at the sea level ambient pressure Large Climatic Wind Tunnel (CWT) at Rail Tec Arsenal (RTA) in Vienna, Austria, by an integrated test team comprising engineers from the Royal Netherlands Aerospace Centre (NLR), Korea Aerospace Industries (KAI), and Safran Helicopter Engines. The test matrix covered the AC29-2C Appendix C 10,000 ft icing envelope, as well as simulated ground icing conditions, considering both a clean and artificially contaminated IBF. Beyond the aforementioned certification conditions, exploratory testing was performed in conditions with Supercooled Large Droplets (SLD) and rain. The test set-up consisted of the front section of the full-scale production cowling with internal modifications to accommodate the test engine and interface with the RTA exhaust gas handling system. Prior to tunnel entry, initial check-out and integration tests were performed with the same set-up at Safran, as well as in the Small CWT at RTA. Data gathering included the delta-pressure across the IBF, static pressures at the Aerodynamic Interface Plane (AIP), engine parameters, high-speed camera imagery, and 3-D scans of the critical ice shapes. The latter was used to support dry air flight testing with simulated ice shapes and blockage to demonstrate altitude effects and measure inlet distortion.