TY - JOUR N2 - One of the main issues of design process of HVAC systems and ventilation ducts in particular is correct modelling of coupling of the flow field and acoustic field of the air flowing in such systems. Such a coupling can be modelled in many ways, one of them is using linearised Euler equations (LEE). In this paper, the method of solving these equations using finite element method and open source tools is decribed. Equations were transformed into functional and solved using Python language and FEniCS software. The non-reflective boundary condition called buffer layer was also implemented into equations, which allowed modelling of unbounded domains. The issue, influence of flow on wave propagation, could be adressed using LEE equations, as they take non-uniform mean flow into account. The developed tool was verified and results of simulations were compared with analytical solutions, both in one- and two-dimensional cases. The obtained numerical results are very consistent with analytical ones. Furthermore, this paper describes the use of the developed tool for analysing a more complex model. Acoustic wave propagation for the backward-facing step in the presence of flow calculated using Navier-Stokes equations was studied. L1 - http://www.czasopisma.pan.pl/Content/118240/PDF/aoa.2020.135251.pdf L2 - http://www.czasopisma.pan.pl/Content/118240 PY - 2020 IS - No 4 EP - 645 DO - 10.24425/aoa.2020.135251 KW - linearised Euler equations (LEE) KW - FEniCS KW - finite element method KW - non-reflective boundary conditions KW - open source A1 - Łojek, Paweł A1 - Czajka, Ireneusz A1 - Gołaś, Andrzej PB - Polish Academy of Sciences, Institute of Fundamental Technological Research, Committee on Acoustics VL - vol. 45 DA - 2020.12.28 T1 - Finite Element Modelling of a Flow-Acoustic Coupling in Unbounded Domains SP - 633 UR - http://www.czasopisma.pan.pl/dlibra/publication/edition/118240 T2 - Archives of Acoustics ER -