A semi-analytical procedure to determine the pressure field in 2D unsteady slightly viscous flows dominated by vorticity

M. VALDEZ; S. PREIDIKMAN; J. C. MASSA; B. BALACHANDRAN; D. T. MOOK

Cancun, Mexico

Congreso; PACAM X - TENTH PAN AMERICAN CONGRESS OF APPLIED MECHANICS; 2008

American Academy of Mechanics (AAM)

The flight of insects is dominated by nonlinear (‘nonlinear’ refers to quantities that can only be described by nonlinear equations) unsteady aerodynamic mechanisms. Their flapping wings offer unique advantages over conventional fixed and rotary wings. To successfully reproduce the aerodynamic mechanisms that generate the lift and propulsion seen in biology, one must completely understand the complex physics underlying such phenomena. In this work, the unsteady aerodynamic interaction between two profiles immersed in an infinite two-dimensional fluid is investigated. An important, but little studied aspect of small-scale flapping-wing flight, the effect of the ground on aerodynamic characteristics, is also investigated. Ground effect is usually studied in one of two ways: the first uses mirror images of the wings and their wakes to make the ground a plane of symmetry; the second panels the ground as well as the wings and their wakes. The former is convenient, but limited to simulating flight near a plane surface. The latter is less convenient, but more appealing because it is capable of simulating flight over irregular contours. In the present simulations, the profiles imitate the typical flapping motion of insects and small birds. The final goal of this work is to contribute a numerical tool for evaluating aerodynamic interactions (often called interference), including ground effect, to support the development of super-maneuverable un-crewed air vehicles (UAVs) powered by flapping wings.