Numerical Analysis of Metal-Foam Application for Trailing Edge Noise Reduction

Abstract

This manuscript presents a numerical investigation of the turbulent boundary layer-trailing edge (TBL-TE) noise reduction with an open-cell porous material. The implementation of the porous media is verified by emulating a facility for characterizing the flow resistivity of the porous material. Subsequently, the porous media is applied on the trailing edge of a NACA 0018 airfoil to examine its capability to mitigate TBL-TE noise. The airfoil is set at zero angle of attack and the chord-based Reynolds number is 2.8 × 10 5. Boundary layer profiles and integral boundary layer quantities have been compared with reference experimental data. The noise reduction obtained with the porous trailing edge at low to mid frequency ranges has been found to be in good agreement with the experiment. However, the simulation is unable to predict the noise increase at high frequency, which is considered due to the neglected surface roughness effects in the adopted porous media model. Conventional beamforming is also used to locate the dominant sound sources. In contrast with the solid trailing edge case, it has been found that the solid-porous interface is the location of the dominant sound source for the porous trailing edge case.

Noise reduction mechanisms of an open-cell metal-foam trailing edge

“…For all three different trailing-edge treatments studied, good agreement is obtained between present results and experimental ones. For instance, the thickening of the boundary layer associated with the porous medium permeability is also captured by the simulation (Geyer & Sarradj 2014;Rubio Carpio et al 2018, 2019bTeruna et al 2019). Similar agreement has also been found for the mean and turbulent velocity profiles as shown in figure 6.…”

“…whose thickness is at least one pore diameter). The APM-PM combination has been previously verified by Teruna et al (2019) in which the pressure drop tests using the porous material characterization rig of Rubio Carpio et al (2017) has been successfully replicated numerically.…”

“…2018, 2019 b ; Teruna et al. 2019). Similar agreement has also been found for the mean and turbulent velocity profiles as shown in figure 6.…”

“…2017; Teruna et al. 2019). Furthermore, due to the random distribution of pores, the metal foam has isotropic and homogeneous properties.…”

Numerical Study on Trailing-Edge Noise Attenuation using 3D-Printed Porous Insert

“…Numerical simulations can be considered as alternatives, for which porous medium models have been developed for [18]. Recently, Teruna et al [13,19] carried out numerical simulations that replicate the experimental setup of Rubio-Carpio et al [14]. The simulation considers an open-cell metal-foam trailing edge that was modeled using an equivalent fluid region governed by the Darcy's law.…”