Biologically Inspired Flight for Micro Air Vehicles

Erin Crawley, Air Force Office of Scientific Research,

Arlington: Air Force Office of Scientific Research officials here recently completed a workshop entitled, “Biologically Inspired Flight for Micro Air Vehicles – MAVs – in Denver.

MAVs are part of a new breed of remotely controlled aircraft that are significantly smaller than currently available remotely controlled aircraft. Most are only about six inches long. Future development of insect-size aircraft is expected in the near future. MAVs are of great interest to the Air Force because of a variety of critical new military needs, chiefly in urban areas.

Over 70 attendees from universities around the world including the United Kingdom, Germany, Australia, Canada and the United States, participated. Government attendees included representatives from the Air Force Research Laboratory (AFRL), the Navy Research Laboratory (NRL), and the Defense Advanced Research Projects Agency (DARPA). Additionally several industry representatives from companies such as Boeing took part in the program.

AFOSR officials used the workshop as a forum for collaboration and to assess current state-of-the-art technologies in the MAV realm, to identify significant technical challenges, and to recommend future research opportunities.

Specific workshop topics included: Flow Physics of Flapping Flight in which attendees discussed flight control options and the flow physics of biology-inspired mechanisms that simultaneously lift, thrust, hover; Bio Inspired Sensing and Actuation in which attendees discussed advances in integrating biology-inspired flight control sensors and methodologies, extreme changes in vehicle configuration, and structural properties that enable gust-tolerant flight; and Computational Approaches for Fluid Structures Interactions – where attendees discussed the development of physically-based predictive models of propulsively effective fluid-structure interationcs and actuation patterns by integrating theoretical, numerical and experimental methods.

The program featured keynote speakers Drs Thomas J. Mueller, Roth-Gibson Professor of Aerospace and Mechanical Engineering, University of Notre Dame, and James DeLaurier, Institute of Aerospace Studies, University of Toronto.

Mueller, who has been on the faculty at Notre Dame for 40 years, specializes in gas dynamics of separated flows, compressible and incompressible fluid mechanics, propulsion aerodynamics, flow visualization, aeroacoustics, and low Reynolds number aerodynamics with applications to MAVs.

DeLaurier has been with the University of Toronto Institute for Aerospace Studies since 1974 and his expertise is in low-speed aerodynamics and aircraft flight dynamics. DeLaurier also has expertise in flapping-wing flight.

Chairman of the organizational committee for this workshop, Lt. Col. Rhett Jefferies, AFOSR program manager, aerospace and materials sciences directorate, described the workshop as a complete success. “Feedback from attendees was overwhelmingly positive and they were excited to participate,” said Jefferies.

Jefferies oversees the unsteady and rotating flows basic research portfolio for AFOSR. Research in turbulence and rotating flows is primarily motivated by Air Force requirements for air-breathing propulsion systems and advanced flight controls. In this context, the program seeks to advance fundamental understanding of complex, turbulent flows, and to apply that understanding to the development of physically based predictive models and innovative concepts for active flow control. Novel approaches for ordering and extracting turbulent flow energy are also sought in this program, along with exploring frontiers in fluid mechanics relating to fundamental flow processes occurring in microscale devices, such as MAVs.

The challenges of this research include exploring ways in which a MAV can successfully operate in an urban or confined environment with the utmost agility. Researchers are trying to find ways to incorporate the ability for MAVs to hover and dwell in a survey environment. Such wide-ranging requirements demand creative integration of traditionally disparate propulsion, aerodynamics, structures, materials, sensors and flight control disciplines. Attendees at the workshop discussed these issues, along with others.

Attendees at this workshop reviewed some ways in which MAVs have the potential to drive advances in aircraft nonlinear flight mechanics models and considered some practical demonstrations of true direct numerical simulations.

By supporting research workshops like this, AFOSR continues to expand the horizon of scientific knowledge through its leadership and management of the Air Force's basic research program. As a vital component of the Air Force Research Laboratory, AFOSR supports Air Force's mission of control and maximum utilization of air and space. Many of the technological breakthroughs enjoyed by millions today, such as lasers, GPS, and the computer mouse trace their scientific roots to research first funded by AFOSR.