The objective of the present work is to understand the effect of ground proximity on the aerodynamic performance and stability of a light unmanned aerial vehicle. The flowfield around the airplane was computed by PAN AIR and Athena Vortex Lattice. The ground effect was simulated using the method of images. The stability coefficients and other aerodynamic characteristics were obtained at different heights above ground and in free flight. The results demonstrate that the airplane is lateral-directional statically stable, longitudinal statically stable in free flight and longitudinal statically unstable in ground effect. The dynamic stability characteristics of the airplane were obtained at different heights above ground. The phugoid mode is considerable influenced by ground effect and a divergent and non-oscillatory mode appears when the airplane is near to the ground. This is called non-dimensional height mode. The short-period, the Dutch roll, the roll and the spiral modes are slightly affected by ground effect. Significant differences were obtained when the z derivatives were neglected in the dynamic analysis for longitudinal motion. The present work demonstrates that the performance and stability of the unmanned airplane are considerably influenced by ground effect.

No abstract

The exploitation of petroleum can cause serious environment problems when oil leakages occur on the marine or lake surfaces. The constant vigilance over exploitation areas helps to minimize the adverse impact of such accidents by means of early detection. This article deals with the activities carried out at present in order to create an unmanned aerial vehicle designed to patrol the petroleum exploitation zones. Among these activities the preliminary design of the aircraft, the structural design of a prototype capable of accomplishing the assigned mission, and the aerodynamic optimization of such a design, are worth mentioning. A monoplane airplane, twin-boom configuration airplane, with a partially metallic structure was designed. The aerodynamic optimization process was realized applying theoretical and experimental methods. In conclusion, the designed vehicle will prove to be satisfactory for the mission for which it was created, and to be used as a tool for future research.

No abstract

The present work has as objective to do a complete aerodynamic analysis of the Unmanned Aerial Vehicle for Ecological Conservation. The panel method code PAN AIR is used to compute the inviscid flowfield. The viscous effects in drag are estimated by the classic Hoerner method, and the maximum lift coefficient via the classic Valarezo and Chin method. The numerical aerodynamic forces of the complete airplane are compared to experimental data for validation. The spanload and wing pressure distribution are estimated for four configurations: wing, wing-body, wing-body-tail, and wing-body-tail with wing twist. The sources of induced drag for all configurations are achieved graphically via Trefftz plane. All the data were estimated at cruise flight, Reynolds number equal to 1.413×10 6 and Mach 0.15.