Investigation of a novel VTOL aircraft concept for operations in urban areas
Experimental investigation on a novel VTOL aircraft named “Anuloid” has been carried out to assess its aerodynamics performances. The study focused on two main aspects: the analysis of the Coandă effect on the 1:20 scaled model without cross-flow and the aerodynamic characterization of the body, performed on the 1:5 scaled model in a large wind tunnel. The first task included the study of the Coandă effect, both in hovering and in ground effect conditions. Basic and modified geometries for the fan duct outlet were also investigated and the influence of the Reynolds number was evaluated. A simplified preliminary analysis on the effectiveness of the maneuverability surfaces was finally conducted. Results evidenced that the Coandă effect is present only for the modified geometries of the outlet section, whereas the basic geometry gives rise to early flow separation. The wind tunnel tests highlighted that the aircraft has poor lift and high drag in normal flight condition, i.e. when α < 0°. In addition to this, the pitching moment is negative in the whole range of angles of attack tested, resulting in longitudinal instability. Finally, pressure distributions revealed massive flow separation on both lower and upper surfaces that gives rise to a very complex unsteady and three-dimensional flow field configuration around the body.
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- 1.B. Lindebaum, “V/STOL concepts and developed aircrafts. Volume 1 A historical report (1949-1986).”, Flight Dynamics Laboratory Report, AFWAL TR 86-3071, Vol. 1, 1986.Google Scholar
- 2.C. Barlow et al., “Investigating the use of Coandă effect to create novel unmanned vehicles.”, International Conference of Manufacturing and Engineering Systems, 2009.Google Scholar
- 3.B. Lindebaum and W. Blake, “The VZ-9 Avrocar”, Available online at, https://web.archive.org/web/20060927042257/http://www.vtol.org/pdf/Vertiflite-VZ9.pdf
- 4.O. Crivoi and I. Doroftei and F. Adascalitei, “A survey of unmanned aerial vehicles based on Coandă effect”, Thenomus Ji, Vol. 20, 2013.Google Scholar
- 5.G. Guitton, “Some contributions to the study of equilibrium and non-equilibrium turbulent wall jet over curved surface”, McGill University, Montreal, 1970.Google Scholar
- 6.W. H. Deckert and W. H. Hodgson, “Avrocar Flight Evaluation”, Airforce Flight Test Center n.270 921, Jenuary, 1962.Google Scholar
- 7.D. S. Allen, “Axisymmetric Coandă-assisted vectoring.”, Utah State University, Utah, 2008.Google Scholar
- 8.B. G. Newman, “The Deflection of Plane Jets by Adjacent Boundaries - Coandă Effect”, Boundary Layer and Flow Control, Pergamon Press, Oxford, Vol. 1, pp 232–264, 1961.Google Scholar
- 9.J. B. Barlow and W. H. Rae and A. Pope, “Low speed wind tunnel testing”, John Wiley, 1984.Google Scholar
- 10.J. B. Barlow and W. H. Rae and A. Pope, “A theory of the blockage effects on bluff bodies and stalled wings in a closed wind tunnel”, Aeronautical research council london 23. (UK), No. ARC-R/M-3400, 1984.Google Scholar