The idea of this project is to implement and use a fluid structure interaction simulation using StarCCM+ to calculate and take into account the flexibility effect in structures due to the influence of aerodynamic forces. Numerical simulations were carried out at low Reynolds numbers on a flexible flat plate with varying stiffness. Different deformation states were obtained. The different states are found to be straight, flapping, deflected and deflected-flapping states. At high value of bending stiffness, the plate remains steady. This is followed by a state of periodic flapping as bending stiffness is decreased. At lower values, the plate deflects on one side but cannot flap back. This analysis was followed by a simulation of plunging motion of the plate by applying sinusoidal actuation to the leading edge of the plate. The motion of the free plate is studied and compared with published literature. The production of thrust and formation of vortex structures around the plate is analyzed.

Wind tunnel experiments to study the various phenomena occurring across the flow past rounded cylinder (D=8 cm) with different passive control devices were performed in the range of Re=3x10^4−1.3x10^5. Complementary numerical simulations are conducted for the reference configuration and for the most successful experimental configurations. The phenomenon of drag decrease is analysed in a smooth cylinder and with a tape strip. The strip promotes the transition of the boundary layer, which does not occur in the baseline cylinder for the range of Re analysed. Passive control of vortex shedding flow at different configurations using splitter plates and the influence of an extra smaller cylinder were investigated. Experimentally, the shedding of the vortices is modified with the strip, a splitter plate of L/D=1 and three splitter plates of L/D=0.5 due to the increment, suppression and reduction of the frequency peaks, respectively. In contrast, the numerical simulations only confirm a downstream displacement of the vortex shedding with passive splitter plates and an additional flow oscillation. A possible interaction with the detached boundary layer of the plate is detected. The splitter plate L/D=0.5 and the secondary cylinder have no beneficial effects. The length, number of splitter plates and the interaction between the generated vortices play a critical role in vortex modification

Flow past plunging NACA 0012 wing at different Strouhal numbers

This report deals with the numerical investigation of the vortical flow for a rectangular wing with a aspect ratio AR = 2, undergoing small amplitude harmonic heave oscillations, within a Reynolds number of 10,000 The results are compared with the experimental work of Gursul & Calderon (2010).

The number of leading-edge vortices generated during a cycle and their arrival time to the trailing-edge appear to determine whether favorable or unfavorable interaction of these vortices will take place. The wing/vortex and vortex/vortex interactions may contribute to the selection of the optimal frequencies for lift. At the relatively lower amplitude of h = 0.025, the presence of multiple vortices on the upper surface are believed to enhance overall suction forces. In the case of h = 0.15, vortices are observed to take a completely different path. At a critical value of Stc = 0.9 − 1.3, the LEV no longer convects downstream due to a destructive interaction with the wing. This, in conjunction with the appearance of a growing lower surface LEV, opposing upper surface suction forces, results in a deterioration in lift.