TECHNOLOGY AREAS: Air Platform, Materials/Processes

ACQUISITION PROGRAM: PEO(A): V-22, H-53, H-60 and H-1

OBJECTIVE: Develop a non-thermal based anti-icing/de-icing system compatible with both metallic and polymer-based composite leading edges.

DESCRIPTION: Existing rotor blade leading edge protection caps are made out of metallic materials to prevent erosion. These materials may be substituted by erosion resistance polymer based composite materials. The de-icing system underneath the leading edge is thermal based and is the only system approved by the DoD and the FAA to prevent ice accretion under icing conditions. Due to large power consumption and economic drawbacks of thermal de-icing, rotary wing aircraft may have to limit their operational capability under severe icing conditions. Thermal de-icing systems are heavy and require large electrical power. As a result, the de-icing system is only run periodically, allowing ice accretion on the rotor. Furthermore melted ice may flow and refreeze further aft. De-bounded pieces of ice could impact sensitive parts of the aircraft [1, 2, 3].

A non-thermal based anti-icing/de-icing system for rotary wing aircraft is needed. The proposed technology should reduce the overall power needed for anti-icing/de-icing the leading edges of rotor blades and improve safety of the aircraft in severe icing condition. Specifically, the proposed technology should demonstrate the anti-icing/de-icing capability through a 0.15" thick leading edge layer within 20 seconds. Suitability of the proposed solution for rotor blade applications should be demonstrated via subscale bench tests.

PHASE I: Develop approaches for non-thermal based anti-icing/de-icing of rotor blade leading edges. Demonstrate the proof of concept through an initial development effort that indicates scientific merit and feasibility of the anti-icing/de-icing mechanism for metallic and polymer based leading edge materials.

PHASE II: Fully develop and optimize the proposed concepts. Design, fabricate and conduct appropriate subscale level experiments to mimic typical severe icing conditions for rotor blades. Demonstrate satisfactory anti-icing/de-icing capability. Demonstrate cost-effectiveness of the proposed technology and feasibility for full-scale rotor blade applications.

PHASE III: Demonstrate the proposed technology on a full-scale rotor blade under icing conditions, and in concert with a major Navy rotor blade manufacturer, qualify and transition this technology to a rotary wing platform.

PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: Successful development of non-thermal based, low-power consumption anti-icing/de-icing systems should enable implementation of the system on all civil rotor blades. Lower-cost, innovative vehicles able to fly under adverse icing conditions will be introduced into the market. Presently, there is a strong need to create a system that prevents ice accretion to allow helicopters to fly during icing conditions [1].

REFERENCES:
1. Coffman, H.J., "Helicopter Rotor Icing Protection Methods," Bell Helicopter Textron Inc., Fort Worth Texas, Journal of the American Helicopter Society 1987.

2. Flemming, R.J., "The Past Twenty Years of Icing Research and Development at Sikorsky Aircraft," 40th AIAA Aerospace Sciences Meeting, January 14th 2002.

3. Bragg, M.B., Bassar, T., Perkins, W. R., Selig, M. S., Voulgaris, P. G., and Melody, J. W., "Smart Icing Systems for Aircraft Icing Safety," AIAA Aerospace Science Meeting January 14th 2002.

4. Palacios, J., L., Smith, E., C., "Dynamic Analysis and Experimental Testing of Thin-Walled Structures Driven By Shear Tube Actuators," 46th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics & Materials, AIAA-2009-2112, Austin, Texas, April 2005.

5. Kandagal, S., and Venkatraman, K., "Piezo- Actuated Vibratory Deicing of a Flat Plate," 46th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics & Materials, AIAA-2009-2115, Austin, Texas, April 2005.

6. M.C. Chu, and R.J.Scavuzzo, Adhesive Shear Strength of Impact Ice, AIAA Journal, Vol. 29, No. 11, November (1991), 1921-1926.

7. Gent, R.W., Dart, N.P., and Candsdale, J.T., "Aircraft Icing," Defense Evaluation and Research Agency, Farnborough, Hampshire GU14 OLX, UK, The royal Society, 2000.

KEYWORDS: Anti-Icing; De-Icing; Ice Accretion; Rotor Blade; Leading Edges; Icing

TPOC: (301)757-2436
2nd TPOC: (301)757-0717