Numerical acoustic analysis of a turbulent flow around a bluff body
Abstract
A body invested by a fluid flow gives rise to vortical and turbulent three-dimensional fields, whose structure depends on the shape of the body itself and the Reynolds number. Then, pressure fluctuations occur in the field and propagate far away as noise. The acoustic analogy based on the Ffowcs Williams-Hawkings (FWH) equation represents a rigorous way to deal with the problem, enabling the evaluation of noise through a post-processing of fluid dynamic data. Moreover, the presence of separate source terms theoretically allows to identify the dominant generating noise mechanisms taking place in the flow, which, of course, repre- sents a key information in view of any possible reduction or alteration of the acoustic field. This paper deals with a numerical, FWH-based acoustic analysis of a turbulent flow around a bluff body and, in particular, a 3D square cylinder in a uniform velocity field. The fluid dynamic solution is obtained through Large eddy simulations carried out using a standard Smagorinsky model at different Reynolds numbers. The acoustic solution is pursued by different integral solution forms of the FWH equation, in the attempt of recognizing the main noise sources and pointing out the potentiality and possible weak-points of the alternative numerical approaches.
- Publication:
-
APS Division of Fluid Dynamics Meeting Abstracts
- Pub Date:
- November 2016
- Bibcode:
- 2016APS..DFD.A4002C