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A computational study of laminar, incompressible flow past a circular cylinder forced to oscillate in the longitudinally, transversely and at an angle to the uniform freestream is performed using the dynamic mesh method. The numerical simulations are conducted at a fixed Reynolds number of 80 and 300 with amplitude ratios from 0.05 to 0.7 and excitation frequency ratios of 0.05 to 3.0. Excellent agreement to previous experimental and numerical investigations is achieved in the prediction of the lock-on range, force amplifications and vortex-shedding modes. Analysis of the wake response of flow past a cylinder oscillating at an angle to the free stream using phaseplane diagrams and the transverse force coefficients revealed two lock-on regions. The extents of these lock-on regions, the variation of the forces, and the near-wake vortex shedding modes are discussed and presented.

Flow-induced noise from fully submerged lifting bodies experiencing turbulent trailing edge flows continues to pose undesirable effects for many marine propulsion systems and control surfaces.This noises arises from unsteady oscillatory flow has been shown to be highly dependent on trailing edge geometry, which can also lead to unacceptable structural vibrations. This paper presents a numerical study of the influence of trailing edge geometry on the immediate wake structure and vortex shedding characteristics, which leads to the generation of flow induced tonal noise.In this study a NACA0015 airfoil is modified at the trailing-edge by vertically cutting at various locations along the axis and thereby changing Re h , where h is the height of the blunt trailing edge, while keeping the chord-length based Re fixed at 3.49 × 10 6 . The computed bluntness parameter for the onset of vortex shedding is found to agree well with published data. Also increasing the trailing edge height has a tendency to reduce the frequency of shedding. The wake formation length variations with Re h resemble that of a circular cylinder. The Strouhal number is shown to be sensitive to the changes of the near wake structure.