The effectiveness of an aerofoil shaped pier reducing down stream vortices and turbulance

Abstract

[Abstract]: This research has examined the phenomenon of vortex shedding that occurs behind a circular pier and an aerofoil shaped pier. A literature review has been conducted in order to assess current knowledge of flow around piers and the effects piers have on downstream turbulence and vortex shedding. The velocity profile down stream of the model piers was measured so that the finer changes in the flow due to the presence of the pier could be observed. This was done with an Acoustic Doppler Velocimeter. These experiments were carried out in the Water Engineering and Thermodynamics Laboratory of the University of Southern Queensland. Two piers were modelled in the research. This consisted of a circular pier with 78mm diameter and an aerofoil pier with a 78mm diameter circular front. The dimensions of the piers were scaled from the Bremer River Bridge using the Froude scaling method. The bridge is located in South East Queensland, Australia. Results were analysed in Microsoft Excel and FLUENT™. The research showed that the aerofoil pier produces a decrease in the drag exerted when compared to the circular pier. The aerofoil pier produces a considerable reduction down stream vortices and turbulence.