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Tailplane with Positive Camber for Reduced Elevator Hinge Moment
Technical Paper
2015-01-2566
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
The Learjet 85 is a business jet with an unpowered manual elevator control and is designed for a maximum dive Mach number of 0.89. During the early design, it was found that the stick force required for a 1.5g pull-up from a dive would exceed the limit set by FAA regulations. A design improvement of the tailplane was initiated, using 2D and 3D Navier-Stokes CFD codes. It was discovered that a small amount of positive camber could reduce the elevator hinge moment for the same tail download at high Mach numbers. This was the result of the stabilizer forebody carrying more of the tail download and the elevator carrying less. Consequently, the elevator hinge-moment during recovery from a high-speed dive was lower than for the original tail.
Horizontal tails are conventionally designed with zero or negative camber since a positive camber can have adverse effects on tail stall and drag. The tailplane sections for the Learjet 85 were tailored to minimize these adverse effects while achieving a significant reduction in elevator hinge-moment. High-speed wind-tunnel tests on a model instrumented for hinge moments, confirmed the benefits of the tailplane with positive camber. A patent has been filed for this tail design.
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Citation
Chandrasekharan, R., Iarocci, N., Vafa, S., and Akel, I., "Tailplane with Positive Camber for Reduced Elevator Hinge Moment," SAE Technical Paper 2015-01-2566, 2015, https://doi.org/10.4271/2015-01-2566.Also In
References
- Torenbeek , E. Synthesis of Subsonic Airplane Design Delft University Press 1981 327
- Code of Federal Regulations Title-14 Aeronautics and Space National Archives and Records Administration 1999
- Mavriplis , D.J. and Martinelli , L. Multigrid solution of compressible turbulent flow on unstructured meshes using a two-equation model Int. Journal for Numerical Methods in Fluids 18 887 914 1994
- Mavriplis , D.J. and Mani , K Unstructured Mesh Solution Techniques using the NSU3D Solver AIAA Paper 2014-0081 2014
- Valarizo , W.O. and Chin , V.D. Method for the Prediction of Wing Maximum Lift Journal of Aircraft 31 1 103 109 1994
- Sting Cart Testing in the Calspan 8-ft Transonic Wind Tunnel Calspan Corporation Technology Center Rep. WTO-539 1995
- Chandrasekharan , R. , Iarocci , N , Vafa , S. , and Akel , I Tailplane with Positive Camber US Patent Application Serial No. 61/856,980 July 2013