27th Congress of the International Council of the Aeronautical Sciences 2010, ICAS 2010, Nice, Fransa, 19 - 24 Eylül 2010, cilt.5, ss.3423-3432, (Tam Metin Bildiri)
The paper discusses hover-to-cruise transition maneuver performance of a small UAV designed for operations in confined spaces and cluttered terrains. The objective of the study is to achieve a transition scheme with minimal variation in altitude, reduced transition time and reasonable thrust-to-weight ratio. For this purpose, the conventional fixed-wing platform is compared with the modified platform having variable-incidence wing referred as 'aerodynamic-vectoring'. The effects of aerodynamic vectoring are discussed in comparison with the conventional configuration based on altitude loss, transition time, thrust-toweight ratio required and the control efforts. A parametric study encompassing the effects of mass and aspect ratio is incorporated to evaluate the design requirements for the platforms. The linearized dynamic analysis in longitudinal plane across the complete transition maneuver is carried out for both configurations. The results indicate that theadvantage of the aerodynamic vectoring increases with the increase in mass and aspect ratio. Moreover the variable-incidence wing can reduce the maximum thrust-to-weight ratio requirement as well as elevator control efforts. Short-period and phugoid mode are also compared.