Effects of unsteady deformation of flapping wing on its aerodynamic forces

Effects of unsteady deformation of a flapping model insect wing on its aerodynamic force production are studied by solving the Navier-Stokes equations on a dynamically deforming grid. Aerodynamic forces on the flapping wing are not much affected by considerable twist, but affected by camber deformation. The effect of combined camber and twist deformation is similar to that of camber deformation. With a deformation of 6% camber and 20° twist (typical values observed for wings of many insects), lift is increased by 10% ∼ 20% and lift-to-drag ratio by around 10% compared with the case of a rigid flat-plate wing. As a result, the deformation can increase the maximum lift coefficient of an insect, and reduce its power requirement for flight. For example, for a hovering bumblebee with dynamically deforming wings (6% camber and 20° twist), aerodynamic power required is reduced by about 16% compared with the case of rigid wings.

[1]  S. Vogel.  Flight in Drosophila : I. Flight Performance of Tethered Flies , 1966 .

[2]  S. Vogel.  Flight in Drosophila : III. Aerodynamic Characteristics of Fly Wing Sand Wing Models , 1967 .

[3]  P. Thomas,et al.  Geometric Conservation Law and Its Application to Flow Computations on Moving Grids , 1979 .

[4]  C. Ellington.  The Aerodynamics of Hovering Insect Flight. III. Kinematics , 1984 .

[5]  C. Ellington.  The Aerodynamics of Hovering Insect Flight. VI. Lift and Power Requirements , 1984 .

[6]  C. Ellington.  The Aerodynamics of Hovering Insect Flight. IV. Aeorodynamic Mechanisms , 1984 .

[7]  A. R. Ennos.  THE IMPORTANCE OF TORSION IN THE DESIGN OF INSECT WINGS , 1988 .

[8]  R. Wootton,et al.  FUNCTIONAL WING MORPHOLOGY AND AERODYNAMICS OF PANORPA GERMANICA (INSECTA: MECOPTERA) , 1989 .

[9]  A. R. Ennos.  The kinematics and aerodynamics of the free flight of some diptera , 1989 .

[10]  Stuart E. Rogers,et al.  Upwind differencing scheme for the time-accurate incompressible Navier-Stokes equations , 1990 .

[11]  R. Dudley,et al.  Mechanics of Forward Flight in Bumblebees: II. QUASI-STEADY LIFT AND POWER REQUIREMENTS , 1990 .

[12]  Stuart E. Rogers,et al.  Steady and unsteady solutions of the incompressible Navier-Stokes equations , 1991 .

[13]  M. Dickinson,et al.  UNSTEADY AERODYNAMIC PERFORMANCE OF MODEL WINGS AT LOW REYNOLDS NUMBERS , 1993 .

[14]  Adrian L. R. Thomas,et al.  Leading-edge vortices in insect flight , 1996, Nature.

[15]  Adrian L. R. Thomas,et al.  FLOW VISUALIZATION AND UNSTEADY AERODYNAMICS IN THE FLIGHT OF THE HAWKMOTH, MANDUCA SEXTA , 1997 .

[16]  Ellington,et al.  A computational fluid dynamic study of hawkmoth hovering , 1998, The Journal of experimental biology.

[17]  Miguel R. Visbal,et al.  Accuracy and Coupling Issues of Aeroelastic Navier-Stokes Solutions on Deforming Meshes , 1997 .

[18]  M. Dickinson,et al.  Wing rotation and the aerodynamic basis of insect flight. , 1999, Science.

[19]  L. Zeng,et al.  Measuring the body position, attitude and wing deformation of a free-flight dragonfly by combining a comb fringe pattern with sign points on the wing , 2002 .

[20]  J. Usherwood,et al.  The aerodynamics of revolving wings II. Propeller force coefficients from mayfly to quail. , 2002, The Journal of experimental biology.

[21]  Mao Sun,et al.  Unsteady aerodynamic force generation by a model fruit fly wing in flapping motion. , 2002, The Journal of experimental biology.

[22]  R J Wootton,et al.  Approaches to the structural modelling of insect wings. , 2003, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[23]  Mao Sun,et al.  Unsteady aerodynamic forces of a flapping wing , 2004, Journal of Experimental Biology.

[24]  S. N. Fry,et al.  The aerodynamics of hovering flight in Drosophila , 2005, Journal of Experimental Biology.

[25]  Mao Sun,et al.  Unsteady aerodynamic forces and power requirements of a bumblebee in forward flight , 2005 .