SBIR 95-1 SOLICITATION
AN ECONOMICAL HYBRID ANTI-ICING SYSTEM
An effective and efficient hybrid ice protection system is proposed to maintain a clean
leading edge (LE) surface on roughness sensitive airfoils with minimum power
requirements. The innovation utilizes the best features of two systems: thermal
anti-icing and mechanical de-icing. A thermal system located at the leading edge will
supply the energy required only to maintain the impinging supercooled water droplets in
a liquid state (running-wet operation). The LE is kept free of ice contamination with
a small fraction of the power that would be required for total evaporation.
Eventually, the runback water will freeze downstream of the heated zone where any
thermal system would be inefficient due to the low surface wetness factor. A Low Power
De-Icing (LPDI) system will be used at those locations to remove the ice accumulation
periodically due to frozen runback while maintaining its thickness below 0.1". This
arrangement has never been explored to the best of our knowledge. The combined system
shall be capable of operating at a low power budget to meet the limitations of Regional
Airliners and modern aircraft with advanced wing designs while maintaining effective
lifting capabilities during icing encounters.
Potential Commercial Applications:
The commercial potential application of the proposed SBIR project covers a broad range
of aircraft categories and classes. This includes turboprop, turbofan, and turbojet
powered aircraft of all categories. Regional Airliners will benefit most from the
innovation due to their relatively limited power budget. This innovation is
particularly beneficial to new and future generation of airfoils that are sensitive to
The hybrid system could be applied to either or both of the wing and horizontal
stabilizer surfaces. Core flow is becoming more scarce in turbofan engines of large
transport category airplanes which could also benefit if this trend continues. The
technology could also be applied to engine inlet nacelles except where FOD is a major
concern; although, the thickness of ice shed is small and could be safely ingested by
the engine without damage to its rotating components.
It is also possible that an electro-thermal or hot air system which is already in place
but whose operation results in unacceptable runback refreeze might be retrofitted and
made to perform satisfactorily. This is accomplished by reducing the heating power
just enough to prevent freezing at the LE, and adding a LPDI system downstream to
shatter the frozen runback.
Name and Address of Offeror:
Cox & Company, Inc.
200 Varick Street
New York, NY 10014
Small Business Innovation Research Program (SBIR) &
Small Business Technology Transfer Program (STTR) Programs
Electronic Management System (EMS)
National Aeronautics and Space Administration (NASA)
The SBIR/STTR EMS site is maintained by Steve
Hu, Hughes STX.
For comments and questions, contact
Updated: Feb. 7, 1996