This paper presents a framework comprising a hybrid computational flow-induced noise solver and finite-element-based phase-conjugation (PC) technique to analyze noise sources generated by bodies immersed in hydrodynamic flow fields at low Reynolds number (Re). The test-cases considered include a bluff and streamlined body, represented by a two-dimensional circular cylinder at Re = 150 and a NACA0012 airfoil at Re = 5000 oriented at \(\text {5}^\circ \) angle of attack, respectively. The hybrid computational flow-induced noise algorithm first resolves the hydrodynamic field using the unsteady pressure implicit splitting of operators (PISO) solver for incompressible Navier–Stokes (NS) equations, which delivers the near-field surface pressure fluctuations (SPF) that are used in the frequency-domain implementation of Curle’s analogy to predict the far-field noise. The vortex shedding plots, lift, and drag spectrum predicted by the PISO solver were in excellent agreement with the computationally expensive direct numerical simulations (DNS). The far-field sound directivity obtained using the SPF in Curle’s analogy and DNS-based prediction were in excellent agreement for the Aeolian tone, while for low-frequency tonal noise emitted from airfoil trailing edge (TE), Curle’s analogy prediction was only approximate. Next, using the boundary data obtained from the hybrid approach, PC was implemented to localize the flow-induced acoustic sources, whereby a pair of focal spots above and below the cylinder and TE revealed the dipole nature at the vortex shedding frequency. However, when the airfoil was modeled, cardioid-shaped focal spots were obtained between the mid-chord and TE due to diffraction of back-propagated waves delivering the reconstructed scattered source location.
