| dc.description.abstract | In this study, the effects of the cross flow around the tandem cylinders on acoustic emissions were investigated. Over 1200 measurements of different configurations of the two cylinders were performed in the wind tunnel of the University of Cottbus (BTU). The measurements were performed with four dimensionless distances of 2.6, 3.2, 3.8, and 4.4, at angles between the center-to-center spacing of two cylinders and the inflow free stream from 0° to 90° in different steps. The inflow velocities were 10,15, 20, 25, and 30 m/s with two different turbulence grids named G1 and G2 were used to generate the turbulence. The results show a strong dependency of the overall sound pressure level on angle and distance. It is shown that two Strouhal peaks occurred in the Strouhal number range of 0.1 to 0.35. The sound pressure level increases from the distance of 2.6 to 3.8 and decrease from 3.8 to 4.4. A prediction model was derived to estimate the noise emissions of the unmeasured configurations. The computational aeroacoustics simulation was also performed on the measured and unmeasured configurations in STAR-CCM+. The simulations were done with the LES method. The results of the simulation show a difference of 12 dB in levels of the highest peak in most cases. However, there was agreement in the corresponding Strouhal number of peak points. | |