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Due to the unsteady motion of a plunging plate, forces acting on the body experience a phase difference with respect to the motion. These phase relations are investigated experimentally for a harmonically plunging plate within an amplitude range of $$0.05\le {a/c}\le 0.6$$ , reduced frequency range of $$0.78

Three-dimensionality effects have been investigated for a flat plate undergoing an impulsive pitch-up motion in a large-scale, free-surface water channel with the presence and absence of an endplate to represent a symmetry plane and to prevent free-surface effects. To obtain the same aspect ratios without using the endplate, appropriately sized wings were also used in a fully submerged arrangement. The velocity fields were acquired in the near wake of the flat plate using a two-dimensional (2D) two-component digital particle image velocimetry system, and simultaneous force measurements were performed. The wing had an aspect ratio ranging from 2 to 8 and pitches up to 45 degrees in 1 or 6 convective times. The force measurement results revealed that major difference occurred after the motion was completed in which the lift and drag forces exhibited a local increase and decrease. Interactions between leading edge, trailing edge, and tip vortices were investigated; flow structures were correlated with the force-time histories, and variations with aspect ratio were also addressed. (C) 2017 American Society of Civil Engineers.

© 2016, (publisher Name). All Rights Reserved. The Applied Vehicle Technology Panel Task Group AVT-202 “Extension of Fundamental Flow Physics to Practical MAV Aerodynamics” has introduced four canonical cases. Rectilinear pitch is probably the most studied one, especially considering its parametric variations. The canonical case of rectilinear pitch considers a rectangular flat plate wing of aspect ratio 4, with a thickness of less than 5% and round edges, undergoing a pitch up motion in a freestream. In the beginning, the wing is at condition CL = 0 and then pitches up to 45° of effective incidence either in 1 or 6 chord lengths of travel relative to fluid (known as fast and slow cases), pivoting around its leading edge. This paper focuses on parametric variations of the aforementioned canonical case, namely variations in aspect ratio, leading edge and planform shapes.