Design Optimization of a Variable-Span Morphing Wing for

The present work focuses on the study, design and validation of a variable-span morphing wing to be fitted to a mini UAV. An in-house aerodynamic shape optimization code, which uses a viscous two-dimensional panel method formulation coupled with a non-linear lifting-line algorithm or a non-linear VLM algorithm and a sequential quadratic programming optimization routine, is used to solve a drag minimization problem to determine the optimal values of wing span for the whole vehicle’s flight speed envelope while subject to geometric constraints. A simple weight representation model based on empirical data obtained from a wing prototype was used to estimate the variable-span wing weight. The UAV flies in the speed range 12m/s to 35m/s. Near its maximum speed it is possible to obtain a 20% wing drag reduction with the variable-span wing in comparison with the original fixed wing. An analysis is also performed to estimate the roll rate available with asymmetric span control showing that the variable-span wing matches the aileron in terms of roll power. An electro-mechanical actuation mechanism is developed using an aluminum rack and pinion system. The wing model is designed with the help of graphical CAD/CAM tools and then a full scale model is built for bench preliminary testing the wing/actuator system.

[1]  J. Anderson,et al.  Numerical lifting line theory applied to drooped leading-edge wings below and above stall , 1980 .

[2]  J. Vale,et al.  Optimization of a Morphing Wing Based on Coupled Aerodynamic and Structural Constraints , 2007 .

[3]  R. Mukherjee,et al.  An Iterative Decambering Approach for Post-Stall Prediction of Wing Characteristics using known Section Data , 2003 .

[4]  Daniel J. Inman,et al.  Aerodynamic and Aeroelastic Considerations of A Variable- Span Morphing Wing , 2004 .

[5]  Pedro Gamboa,et al.  Design of a Variable Camber Flap for Minimum Drag and Improved Energy Efficiency , 2009 .

[6]  J. Katz,et al.  Low-Speed Aerodynamics , 1991 .

[7]  Robert C. Nelson,et al.  Flight Stability and Automatic Control , 1989 .

[8]  Afzal Suleman,et al.  Design of a Morphing Airfoil Using Aerodynamic Shape Optimization , 2006 .

[9]  John Flanagan,et al.  Development and Flight Testing of a Morphing Aircraft, the NextGen MFX-1 , 2007 .

[10]  William A. Crossley,et al.  Comparison of Morphing Wing Strategies Based Upon Aircraft Performance Impacts , 2004 .

[11]  Darryll J. Pines,et al.  Stability Analysis for UAVs with a Variable Aspect Ratio Wing , 2005 .

[12]  Afzal Suleman,et al.  Sequential Optimization Algorithms for Aerodynamic Shape Optimization , 2004 .

[13]  Darryll J. Pines,et al.  Pneumatic Morphing Aspect Ratio Wing , 2004 .

[14]  Afzal Suleman,et al.  Numerical Evaluation of Optimization Algorithms for Low-Reynolds-Number Aerodynamic Shape Optimization , 2005 .

[15]  Darryll J. Pines,et al.  A Mathematical Model for Roll Dynamics by Use of a Morphing-Span Wing , 2007 .

[16]  Daniel P. Raymer,et al.  Aircraft Design: A Conceptual Approach , 1989 .

[17]  Miguel Silvestre,et al.  Evaluation of a Variable-Span Morphing Wing for a Small UAV , 2011 .

[18]  Giuliano Allegri,et al.  48th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Honolulu, USA , 2007 .

[19]  Daniel J. Inman,et al.  Design and Wind-Tunnel Analysis of a Fully Adaptive Aircraft Configuration , 2004 .

[20]  Jayanth N. Kudva,et al.  Development of Next Generation Morphing Aircraft Structures , 2007 .

[21]  Andrew Simpson,et al.  Development of a Finite Element Model of Warping Inflatable Wings , 2006 .

[22]  Tim Smith,et al.  Inflatable and Rigidizable Wings for Unmanned Aerial Vehicles , 2003 .