Numerical Experiments of Forced Cylinder Oscillations at an Angle to Oncoming Flow

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.