Breakdown Voltage Enhancement Through Lateral Vapor Phase Epitaxy

Not Available In the course of developing the solar powered Pathfinder and Centurion high altitude long endurance (HALE) uninhabited air vehicles (UAVs), AeroVironment has done extensive investigations into the effects of atmospheric turbulence on this unusual class of aircraft. This investigation found that turbulent loads are the driving factor in the design of these vehicles. In particular, two-or three dimensional turbulent motions give rise to higher loads that those from the maneuvering or one-dimensional gust loads used in classical aircraft design. Existing turbulent loads analysis techniques and data were found to be inadequate when trying to estimate the design loads for such flexible and lightweight aircraft. It was also found that almost no statistical turbulence data exists for aircraft that cruise for months at extreme altitudes and may experience only one or two takeoffs and landings during their design lifetime. As a result, the current generation of aircraft may have been significantly over-designed to account for uncertainty in the expected turbulence loads. Solar powered aircraft may have been significantly over-designed to account for uncertainty in the expected turbulence loads. Solar powered aircraft performance depends very strongly on being able to reduce weight. This document proposes to investigate the feasibility of a system that, through both an active control system for direct reduction of turbulence induced loads and, through the indirect development of a significant database of high altitude turbulence information, will lead to reduced structural weight and greatly improved performance for HALE UAVs.