Researchers envision aircraft powered by solar, heat energies

Published Sept. 8, 2006
By William J. Sharp
Air Force Office of Scientific Research Public Affairs

ARLINGTON, Va. -- The Air Force Office of Scientific Research here recently awarded the University of Washington and three partner universities a grant worth approximately $6 million over 5 years to study the design of air vehicles capable of collecting and storing solar and heat energies.

One of the goals of the research is to enhance Air Force air vehicle systems but there are many potential applications in other areas such as space platforms. The MURI grant - or Multidisciplinary University Research Initiative - was presented in Seattle at the University of Washington, the lead university for this grant. Under the grant, UW will collaborate with the University of Colorado, the University of California at Los Angeles, and Virginia Polytechnic Institute.

"While running air vehicles or space platforms, there are presently three main sources for harvesting energy with non-fossil origins - sunlight, heat, and vibration," said Dr. B. L. "Les" Lee, program manager at AFOSR's Aerospace and Materials Sciences Directorate. The source of the heat energy, he said, can be aerodynamic heating caused by high flying speed or the recycling of waste heat around an aircraft cabin or engine. Each of the three sources, he explained, is capable of generating electricity, but sunlight and heat energies show the greatest potential in terms of significant power output. As a result, the proposed research will focus primarily on these two energy sources.

Researchers will explore a variety of topics concerning materials and micro devices associated with so-called photovoltaic energy - or electricity generated from light sources - and thermoelectric energy - or electricity generated from heat sources. Once fully developed, these systems may one day enable air vehicles to fly solely on solar energy and aerodynamic heat. The systems may also find application in cabin operation on commercial airplanes.

"For integration of energy harvesting and storage devices into air vehicles with minimal increase of weight, we hope to create a new generation of multi-functional materials that can, for example, maintain structural integrity in flight while at the same time serve as energy collectors and storage units," Dr. Lee said.

The goal is challenging because of the interaction of many different disciplines of sciences involved in this study. Another interesting aspect of the research is an enhanced approach to technology development and system integration.

"Electronics communities are always looking to improve energy-generating efficiencies of devices while structural communities of mechanical and materials engineers are looking to improve aircraft design in terms of weight and mechanical performance," Dr. Lee said. "Essentially, our research attempts to do both in a single step. We consider this a really futuristic way of doing business with higher efficiency."