International Journal of Civil & Structural Engineering
Open Access
  • Year: 2011
  • Volume: 2
  • Issue: 1

Numerical investigations of Coandă lift on a double curvature super circulated ramp

  • Author:
  • Valeriu Drăgan
  • Total Page Count: 8
  • Page Number: 241 to 248

“POLITEHNICA” University Bucharest, Faculty of Aerospace Engineering Str. Gheorghe Polizu, nr. 1, sector 1, 011061, Bducharest, Romania. Email: drvaleriu@gmail.com

Online published on 7 February, 2013.

Abstract

The paper relies on Henri Coandă’s observations of very thin flows over curved surfaces in the late 1930’s in which it became apparent that such an arrangement would yield more lift than the thrust of a jet having the same mass flow. Since then various experiments have been carried out culminating with the development of super circulation aircraft such as the Antonov An-71 and the Boeing YC-14. Those aircraft however do not fully take advantage of effect, relying mostly on diverting the fan flow downwards trough gapless flaps. In this paper we try to investigate numerically the lifting properties of thin jets, at various velocities in the subsonic regime. The method used is a 2D computational fluid dynamic, Reynolds averaged Navier-Stokes with a k-epsilon two equation viscosity model. The results obtained indicate that, indeed such thin flows generate higher lift than if the flow were to be directed downwards. Efficiency and effectiveness parameters have been defined in order to estimate the feasibility of further real life applications of this effect per se in aircraft wings or turbo machinery blades. The findings are encouraging however they still require experimental validations.

Keywords

super circulation, Coandã effect, lenticular aerodyne, RANS, CFD