Any sound which is unwanted in the specific context could be termed noise. When a fluid flows around stationary/moving objects, sound is produced and is generally termed flow induced noise. Noise management is essential to maintain low noise exposures, such that human health and environment wellbeing is protected. Estimation of noise in various fluid flow regimes is important in designing and devising methods to mitigate it. Some areas where noise control is essential include aircraft landing gears, high speed trains, automobiles, offshore structures, subsea pipelines etc.

We use large eddy simulations (LES) and acoustic analogy to estimate far field sound from infinitely long circular cylinders in sub-critical fluid flow regime. Usually, numerical simulations are performed for shorter span lengths and correction method based on spatial coherence length (Lc) is used to compensate for the sound from nonsimulated lengths. Such correction methods are already established and proven effective for circular frontal shaped geometries (circular cylinder, aerofoils etc.). In the present study, we investigate whether such correction methods can be applied to flat frontal shapes including square, half square-half circular etc. Numerical simulations were done to investigate the aeroacoustic characteristics of the flow past a circular cylinder for Reynolds number ranging from 3900 to 145000 in air and water medium. We intend to create a comprehensive database for spatial coherence lengths in both mediums for the above Re range. Such a database will help in estimating far field sound from circular shaped objects for any Re number in the range.