Plunging motions of an elastically suspended wing with an oscillating flap: An experimental and numerical assessment

Plunging motions of an elastically suspended wing with an oscillating flap: An experimental and numerical assessment

Sterenborg, J.J.H.M.

Bijl, H. (promotor)

Aerospace Engineering

Aerodynamics

2014-10-13

For wind turbines there is need for accurate fluid-structure interaction predictions due to among others increasing wind turbine blade length and the design of load alleviation systems based on aero-elastic blade deformations, like bend-twist coupling. Currently, engineering models are widely used to simulate fluid-structure interactions for wind turbines. These models typically have a limited accuracy and a new generation of design tools with a higher accuracy is desired. Important in the development of such tools is validation data, which is not widely available for wind turbine applications. Therefore, in this work experiments are conducted to generate validation data for wind turbine applications. An elastically suspended rigid wing with a flap oscillating at reduced flap frequencies of 0.1 < k < 0.3 is tested at a Reynolds number of Re=700 000. The wing freely moves in the cross-flow direction at angles of attack in the linear lift regime. Forces, moments and displacements are measured and uncertainties are determined. The resulting database is useful for comparative studies. For validation additional experiments are required, for which this work is valuable since the setup, data and experiences can be used as a starting point. Simulations are conducted with three aero-elastic codes of different fidelity: Theodorsens model, an inviscid panel code and an URANS solver. All simulations are 2-D and wind tunnel corrections are incorporated such that a low-cost approximation can be achieved. Part of the simulations were used initially to design the experiment and finally a benchmark study is conducted, demonstrating that good approximations of the experimental data are found with all models.

aero-elasticity
flaps
experimental
wind tunnel correction

https://doi.org/10.4233/uuid:a4fc4b94-0294-44ca-a504-277ede973d0b

9789462593534

Institutional Repository

doctoral thesis

(c) 2014 Sterenborg, J.J.H.M.