Modeling of the Urban Gust Environment with Application to Autonomous Flight

Abstract

Desirable surveillance applications of unmanned aerial vehicles (UAV) around urban areas provides motivation for the investigation of turbulent wind generated by buildings which can potentially cause instability in aircraft flight. It has been shown that the urban canyons an d single buildings which form the basic components of the urban geometry have classifiable flows with signi ficant degrees of circulation and shear, a potential danger to light aircraft. A first generation methodology is p roposed by which wind data important to flight planning in an urban environment is selected, accessed and applied. It is assumed the urban environment can be represented as a combination of discrete single buildings and canyons each easily amenable to computational fluid dynamics (CFD). A set of single buildings an d canyons typical to the North American urban environment is selected to provide a set of wind data. A selection algorithm is proposed which will determine if the flow at a location in a given urban environment fits a member of the wind data set. Results from simulations for the Aerosonde UAV in a simple urban environment are presented and analyzed.