Numerical investigation of the turbulent flow around a truncated cylinder: noise reduction aspects

This paper presents a numerical investigation by mean of Large Eddy Simulation of the turbulent flow around a regular circular cylinder, and around one which is truncated in its rear part. Such a configuration was inspired by the experimental works of Kopiev et al., who suggested that performing a truncation of the cylinder should lead to a significant reduction of the noise emitted by the turbulent flow past the cylinder. In our simulations, it is observed – as already done in experiments – that a significant reduction (-2dB) of the noise radiation intensity is obtained in the truncated geometry case. A careful analysis of both the acoustic and aerodynamic results is then performed in order to highlight specific flow modifications that may be responsible for this noise reduction.