scholarly journals Impact of entry–exit loss on the measurement of flow resistivity of porous materials

AIP Advances ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 105031
Author(s):  
Swati Sachan ◽  
Sanjeet Kumar ◽  
Shankar Krishnan ◽  
Sripriya Ramamoorthy
Keyword(s):  
Porous Materials ◽  
Flow Resistivity

Modelling of Rigid-Frame Porous Materials: A Simple Approach

2000 ◽  
Author(s):  
M. J. Brennan ◽  
W. M. To
Keyword(s):  
Porous Material ◽  
Porous Materials ◽  
Characteristic Impedance ◽  
Simple Approach ◽  
Middle Ground ◽  
Acoustic Behaviour ◽  
Rigid Frame ◽  
Flow Resistivity ◽  
Stiffness And Damping ◽  
Optimum Flow

Abstract This paper is concerned with the modelling of rigid-frame porous materials. Currently there are very simple models which describe the acoustic behaviour of such materials, and there are also very complicated models. The aim of this paper is to present a model which occupies the “middle ground”, but is simple enough to be used by practising noise control engineers. Using concepts of acoustic mass, stiffness and damping, non-dimensional expressions for the acoustic wavenumber and the characteristic impedance of a rigid-frame porous material are derived. These expressions are used to give a “rule of thumb” for the optimum flow resistivity for a given thickness of material.

Measuring flow resistivity of porous materials at low frequencies range via acoustic transmitted waves

2006 ◽  
Vol 119 (4) ◽  
pp. 1926-1928 ◽  
Author(s):  
Z. E. A. Fellah ◽  
M. Fellah ◽  
N. Sebaa ◽  
W. Lauriks ◽  
C. Depollier
Keyword(s):  
Porous Materials ◽  
Low Frequencies ◽  
Transmitted Waves ◽  
Flow Resistivity

scholarly journals Production and characterization of experimental low noise trailing edges made of cold rolled porous aluminum with special attention to the influence of cold rolling on the mechanical stability of the investigated materials

2021 ◽  
Author(s):  
Jörn Tychsen ◽  
Joachim Rösler
Keyword(s):  
Cold Rolling ◽  
Porous Materials ◽  
Rolling Process ◽  
Low Noise ◽  
Important Method ◽  
Porous Aluminum ◽  
Trailing Edges ◽  
Cold Rolled ◽  
Flow Resistivity

AbstractIn the framework of the CRC 880 “Fundamentals of high-lift for future civil air craft” methods for the reduction of aircraft noise are investigated. An important method for this noise reduction is the usage of porous material as low noise trailing edges. To improve the aeroacoustic properties of porous materials, an innovative rolling process was established by Tychsen et al. (Metals 8:598, 2018). Here, the rolling process is described as it is used as an important method for the production of samples. The influence of cold rolling on two different porous materials namely porous aluminum 80–110 (PA 80–110) and PA 120–150 is investigated. Important characteristics studied are the porosity, mechanical properties and the dependence of flow resistivity from the degree of deformation. The flow resistivity is of particular interest as the aeroacoustic performance is significantly influenced by it. The results are then compared to the findings for PA 200–250, which was investigated in Tychsen et al. (Metals 8:598, 2018). Lastly, experimental trailing edges made out of cold rolled porous aluminum with a gradient in thickness reduction are shown. The characterization of the aeroacoustic behavior is not part of this study. Reference is made to Rossignol et al. (Int J Aeroacoust 19:365–384, 2020), where trailing edges shown here are characterized aeroacoustically. The findings shown here demonstrate that different porous materials can be tailored by cold rolling without negative impact on the mechanical behavior. It is proven that the new rolling process is a versatile tool for the production of gradient porous material.

Measurement and inverse estimation of 3D anisotropic flow resistivity for porous materials

2009 ◽  
Vol 327 (3-5) ◽  
pp. 354-367 ◽  
Author(s):  
Peter Göransson ◽  
Rémi Guastavino ◽  
Nils-Erik Hörlin
Keyword(s):  
Porous Materials ◽  
Anisotropic Flow ◽  
Inverse Estimation ◽  
Flow Resistivity

Porous materials from cellulose nanocrystal and mxene surfactants at the oil/water interface

2020 ◽  
Author(s):  
Bingqing qian ◽  
Haiqiao Wang ◽  
Dong Wang ◽  
Hao-Bin Zhang ◽  
Jessica Wu ◽  
...  
Keyword(s):  
Porous Materials ◽  
Cellulose Nanocrystal ◽  
Water Interface ◽  
Oil Water

Effect of structure of porous materials on their self-cleaning from a liquid pha

2018 ◽  
Vol 4 (4) ◽  
pp. 52-63
Author(s):  
V. Yu. Shumskaya ◽  
S. F. Zhandarov ◽  
L. A. Kalinin ◽  
L. F. Ivanov ◽  
V. V. Snezhkov ◽  
...  
Keyword(s):  
Porous Materials ◽  
Self Cleaning ◽  
Effect Of Structure
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