Study on Vortex Flow around Elastic Airfoil and Thin Film Determined by Reynolds number, Strouhal number and Bending Stiffness

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420126
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Fluid engineering
• Research Institution: Kyushu Institute of Technology
• Principal Investigator: Fuchiwaki Masaki 九州工業大学, 大学院情報工学研究院, 准教授 (60346864)
• Co-Investigator(Kenkyū-buntansha): Kazuhiro Tanaka 九州工業大学, 大学院情報工学研究院, 教授 (80171742)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 非定常流れ / はく離 / 翼 / 非定常運動 / 渦

Outline of Final Research Achievements

The bending stiffness of an elastic airfoil with a non-uniform cross-section is uniquely determined by the thickness at the position of the center of gravity and the span length, independent of the shape or thickness of the airfoil. It is an important parameter that determines the bending characteristics and the moving boundary conditions at the wall surfaces in the fluid. The characteristic of dynamic forces acting on a heaving elastic airfoil depends on the ratio St2/K. In the regime below the critical Reynolds number, the impact of this parameter is extremely small. For a thin film, the LEVs produced from the leading edge and the TVs produced by the trailing edge interfere strongly and form a vortex ring. An accelerating flow arises even far into the wake of the thin film, because the vortex rings evolve towards the wake at an incline with respect to the main flow, and a substantial propulsive force is induced over almost the entire pitching cycle for an elastic thin film.

Free Research Field

流体工学