TY - JOUR

T1 - The estimation of pressure on the surface of a flapping rigid plate by stereo PIV

AU - Suryadi, Alexandre

AU - Obi, Shinnosuke

N1 - Funding Information:
The present work has been supported by a research fund provided by the Keio Leading-edge Laboratory. The authors are grateful to Dr. Y. Naka for his assistance in conducting experiments and to Prof. K. Fukagata for valuable discussions.

PY - 2011/11

Y1 - 2011/11

N2 - The method to estimate the dynamic load of a flapping wing by the integration of pressure on the wing's surface is discussed. The flapping wing was modeled as a plate flapping sinusoidally in hovering condition. The flow around the flapping plate was measured using stereo PIV on multiple measurement planes along the out-of-plane direction. The phase-averaged velocity field of each measurement plane was calculated so that three-dimensional analyses could be applied. The phase-averaged pressure field was obtained from the integration of the three-dimensional Poisson equation for pressure using the available information acquired from stereo PIV measurements. The pressure field is visualized on the measurement planes. In this study, the estimated load was the torque of the axis of rotation. This torque was compared with the result from strain gauge measurements. The torque estimation, although only on a partial surface of the plate, is within reasonable agreement with the measured torque. The integration of the Poisson equation based on stereo PIV measurements and estimations of the torque shows that an increase in the torque at the start of a flapping stroke is caused by the stagnation on the surface of the plate from the flow that is induced by the leading-edge vortices.

AB - The method to estimate the dynamic load of a flapping wing by the integration of pressure on the wing's surface is discussed. The flapping wing was modeled as a plate flapping sinusoidally in hovering condition. The flow around the flapping plate was measured using stereo PIV on multiple measurement planes along the out-of-plane direction. The phase-averaged velocity field of each measurement plane was calculated so that three-dimensional analyses could be applied. The phase-averaged pressure field was obtained from the integration of the three-dimensional Poisson equation for pressure using the available information acquired from stereo PIV measurements. The pressure field is visualized on the measurement planes. In this study, the estimated load was the torque of the axis of rotation. This torque was compared with the result from strain gauge measurements. The torque estimation, although only on a partial surface of the plate, is within reasonable agreement with the measured torque. The integration of the Poisson equation based on stereo PIV measurements and estimations of the torque shows that an increase in the torque at the start of a flapping stroke is caused by the stagnation on the surface of the plate from the flow that is induced by the leading-edge vortices.

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U2 - 10.1007/s00348-011-1150-y

DO - 10.1007/s00348-011-1150-y

M3 - Article

AN - SCOPUS:82955163013

SN - 0723-4864

VL - 51

SP - 1403

EP - 1416

JO - Experiments in Fluids

JF - Experiments in Fluids

IS - 5

ER -