On the influence of porous coating thickness and permeability on passive flow and noise control of cylinders

Sharma，Sparsh1; Geyer，Thomas F.1; Arcondoulis，Elias J.G.2

2023-04-14

10.1016/j.jsv.2023.117563

JOURNAL OF SOUND AND VIBRATION   Impact Factor & Quartile

0022-460X

1095-8568

Aeroacoustic studies of porous cylinder coatings, which reduce the vortex shedding noise of cylinders in uniform flow, have received increased attention. To further understand how porous coatings suppress the vortex shedding tone, a numerical and experimental investigation of porous coated cylinders at a Reynolds number of 1.27×10 is presented herein. Two parameters were varied: (1) the ratio of the porous thickness to the bare cylinder diameter, and (2) the airflow resistivity of the porous media. Numerical simulations were performed using the large-eddy simulation approach with the Smagorinsky sub-grid length-scale model, and the Ffowcs-Williams and Hawkings acoustic analogy was used to predict the acoustic far-field pressure field. A numerical investigation of the internal flow field within the porous layer is presented, which provides a better understanding of the influence of the aforementioned parameters on the development of boundary layers within the porous media and the passive flow and noise control capability. Experiments were performed in an aeroacoustic open-jet wind tunnel to validate the acoustic and external flow field results, which typically showed very good agreement with the numerical results. For porous coatings with low airflow resistivity, the thickness of the porous coating, relative to the inner diameter, has a strong influence on passive flow and noise control. Vortex shedding originates from the inner diameter. Conversely, porous coatings with a higher airflow resistivity are less influenced by their thickness, and vortex shedding originates from the outer diameter (porous surface). The complex coupling of these parameters leads to the conclusion that the optimal selection of the thickness and airflow resistivity is typically dependent on the Reynolds number.

Aeroacoustics Passive flow control Porous media Vortex shedding

SCI

English

Others

Acoustics ; Engineering ; Mechanics

Acoustics ; Engineering, Mechanical ; Mechanics

WOS:000925407300001

ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD

ENGINEERING

2-s2.0-85147248743

Scopus

1.Technical Acoustics,Brandenburg University of Technology Cottbus - Senftenberg,Cottbus,03046,Germany
2.Department of Mechanics and Aerospace Engineering,Southern University of Science and Technology,Shenzhen,518055,China

Sharma，Sparsh,Geyer，Thomas F.,Arcondoulis，Elias J.G.. On the influence of porous coating thickness and permeability on passive flow and noise control of cylinders[J]. JOURNAL OF SOUND AND VIBRATION,2023,549.

Sharma，Sparsh,Geyer，Thomas F.,&Arcondoulis，Elias J.G..(2023).On the influence of porous coating thickness and permeability on passive flow and noise control of cylinders.JOURNAL OF SOUND AND VIBRATION,549.

Sharma，Sparsh,et al."On the influence of porous coating thickness and permeability on passive flow and noise control of cylinders".JOURNAL OF SOUND AND VIBRATION 549(2023).