Effect of Flow Curvature on Forward Flight Performance of a Micro-Air-Vehicle-Scale Cycloidal-Rotor

This paper describes the systematic experimental and computational studies performed to obtain a fundamental understanding of the physics behind the lift and thrust production of a cycloidal rotor (cyclorotor) in forward flight for a unique blade pitching kinematics. The flow curvature effect (virtual camber and incidence due to the curvilinear flow) was identified to be a key factor affecting the lift, thrust, and power of the cyclorotor in forward flight. The experimental study involved systematic testing of a micro air vehicle-scale cyclorotor in an open-jet wind tunnel using a custom built three-component balance. The key parameters varied include rotor chord/radius ratio and blade pitching axis location because these two parameters have a strong impact on flow curvature effects. Because of the virtual camber/incidence effects and the differences in the aerodynamic velocities around the azimuth, the blades produce a small downward lift when they operate in the upper half of the circular trajectory and...

[1]  I. Hwang,et al.  Development of a Four-Rotor Cyclocopter , 2008 .

[2]  P. Spalart.  A One-Equation Turbulence Model for Aerodynamic Flows , 1992 .

[3]  Ranjith Mohan,et al.  A Unified Assessment of Fast Floquet, Generalized Floquet, and Periodic Eigenvector Methods for Rotorcraft Stability Predictions , 2013 .

[4]  J. Gordon Leishman,et al.  Performance of a Cycloidal Rotor Concept for Micro Air Vehicle Applications , 2010 .

[5]  Benjamin Hein,et al.  Hover Performance of a Micro Air Vehicle: Rotors at Low Reynolds Number , 2007 .

[6]  Yuval Levy,et al.  Experimental and Numerical Study of Cyclogiro Aerodynamics , 2006 .

[7]  P. G. Migliore,et al.  Flow Curvature Effects on Darrieus Turbine Blade Aerodynamics , 1980 .

[8]  P. Roe.  Approximate Riemann Solvers, Parameter Vectors, and Difference Schemes , 1997 .

[9]  D. Pines,et al.  Challenges Facing Future Micro-Air-Vehicle Development , 2006 .

[10]  Inderjit Chopra,et al.  Effect of Rotor Geometry and Blade Kinematics on Cycloidal Rotor Hover Performance , 2013 .

[11]  James D. Baeder,et al.  Computational Investigation of Small Scale Coaxial Rotor Aerodynamics in Hover , 2009 .

[12]  Inderjit Chopra,et al.  Experimental Investigation of the Forward Flight Performance of a MAV-Scale Cycloidal Rotor , 2012 .

[13]  Inderjit Chopra,et al.  Improving the Aerodynamic Performance of Micro-Air-Vehicle-Scale Cycloidal Rotor: An Experimental Approach , 2010 .

[14]  Kevin Henry,et al.  Development of a Micro Air Vehicle for Maximum Endurance and Minimum Size , 2003 .

[15]  Vinod K. Lakshminarayan,et al.  Computational investigation of micro-scale coaxial rotor aerodynamics in hover , 2010 .

[16]  B. Koren.  Multigrid and defect correction for the steady Navier-Stokes equations , 1990 .

[17]  Inderjit Chopra.  Hovering micro air vehicles: Challenges and opportunities , 2013 .

[18]  T. Pulliam,et al.  A diagonal form of an implicit approximate-factorization algorithm , 1981 .

[19]  Ray Windler,et al.  Wind-tunnel tests of a cyclogiro rotor , 1935 .

[20]  P. Masarati,et al.  Aeroelastic Analysis of a Micro-Air-Vehicle-Scale Cycloidal Rotor in Hover , 2011 .

[21]  Inderjit Chopra,et al.  Experimental Optimization of MAV-Scale Cycloidal Rotor Performance , 2011 .

[22]  B. V. Leer,et al.  Towards the Ultimate Conservative Difference Scheme , 1997 .

[23]  Sergey V Shkarayev,et al.  Numerical Simulations of Low Reynolds Number Flows Around Micro Air Vehicles and Comparison against Wind Tunnel Data , 2006 .

[24]  Matthew T. Keennon,et al.  Development of Two MAVs and Vision of the Future of MAV Design , 2003 .

[25]  Inderjit Chopra,et al.  Hover performance of a cycloidal rotor for a micro air vehicle , 2007 .

[26]  Peter Ifju,et al.  Flexible-wing-based Micro Air Vehicles , 2002 .

[27]  Curtis Boirum,et al.  Review of Historic and Modern Cyclogyro Design , 2009 .

[28]  E. Turkel,et al.  PRECONDITIONING TECHNIQUES IN COMPUTATIONAL FLUID DYNAMICS , 1999 .

[29]  Matthew T. Keennon,et al.  Development of the Black Widow Micro Air Vehicle , 2001 .

[30]  Benedict Moble,et al.  FUNDAMENTAL UNDERSTANDING OF THE CYCLOIDAL-ROTOR CONCEPT FOR MICRO AIR VEHICLE APPLICATIONS , 2010 .