On the 3D structure of the flow-field in the vicinity of inclined plate

P Prochazka,V Uruba,V Skala

doi:10.1088/1742-6596/1101/1/012026

Abstract

The motivation of the presented study is supporting new ideas about principle of flight by Hoffman and Johnson, see [1]. The new hypothesis of physical mechanism of flight relies on existence of streamwise vortical structures on the suction side of the airfoil and within its wake. The vortices origin is supposed to be the instability of the boundary layer subjected to adverse pressure gradient. The vortices are of highly dynamical nature, changing theirs position, size and other parameters in time very rapidly. For this experiment the simplest airfoil possible was chosen represented by a flat plate in uniform flow and moderate angle of attack. In the suggested paper detailed measurement of the zone of interest will be carried out using stereo PIV method. System of measuring planes perpendicular to the flow will be explored. POD analysis is to be utilized.

Highlights

The generation of the lift seems to be resolved issue in the community of people dealing with the aerodynamics
The true physical principal of lift and flight has been investigated by authors Hoffman and Johnsson [1, 2]. They formulated some new ideas - the downwash effect is a necessary condition to generate the lift and the downwash is coming from a low-pressure rotational slip separation
The streamwise vorticity is presented as a consequence of the natural instabilities of the boundary layer developing under adverse pressure gradient on the airfoil suction side

Summary

Introduction

The generation of the lift seems to be resolved issue in the community of people dealing with the aerodynamics. The main source of the lift generation should be the existence of the streamwise vortical structures located above the wing and in the wake behind it. The streamwise vorticity is presented as a consequence of the natural instabilities of the boundary layer developing under adverse pressure gradient on the airfoil suction side.

Results

Conclusion