Global Journal of Researches in Engineering, I: Numerical Methods, Volume 23 Issue 1

IV. C onclusion In conclusion, this study investigated the influence of physical parameters on the reflected wave at the 1st and 2nd interface of rigid porous media in the low-frequency ultrasound regime. The results show that porosity and tortuosity are the most influential parameters affecting the two reflected signals. This influence varies proportionally with the frequency and inversely with the porosity for both the 1st and 2nd reflected waves. For the 1st reflected wave, the influence varies proportionally with the tortuosity and frequency, while for the 2nd reflected wave; it varies proportionally with the tortuosity and inversely with the frequency. However, the impact of porosity and tortuosity on the 1st reflected wave is greater than on the 2nd reflected wave. Moreover, the viscous characteristic length has a small effect on the 1st reflected wave but a substantial influence on the 2nd reflected wave, exceeding the impact of tortuosity. On the other hand, the shape factor has a minor impact on the 1st reflected wave and a significant sensitivity on the 2nd reflection. Concerning the thermal parameters, the thermal characteristic length and the thermal shape factor have a negligible impact on the 1st reflected wave, while the sensitivity of the thermal characteristic length on the 2nd reflected wave is considerable. The study's strength is that it analyzed the two reflected waves separately and independently, which allows us to treat each wave individually. These results could have important implications for the design and optimization of ultrasound-based techniques in various applications such as medical imaging, non-destructive testing, and materials characterization. However, further research may be necessary to investigate the effect of these parameters in other frequency ranges and porous medium structures. A cknowledgment This work was funded by The General Directorate of Scientific Research and Technological Development (DGRSDT) under grant number PRFU: B00L02UN440120200001, Algeria. R eferences R éférences R eferencias 1. Day, G. S., Drake, H. F., Zhou, H. C., & Kitagawa, S. (2021). Evolution of porous materials from ancient remedies to modern frameworks. Communications Chemistry, 4(1), 114. 2. Khanafer, K., & Vafai, K. (2006). The role of porous media in biomedical engineering as related to magnetic resonance imaging and drug delivery. Heat and Mass Transfer, 42, 939-953. 3. Rashidi, S., Abolfazli Esfahani, J., & Karimi, N. (2018). Porous materials in building energy technologies—A review of the applications, modeling, and experiments. Renewable and Sustainable Energy Reviews, 91, 229-247. 4. Teruna, C., Rego, L., Avallone, F., Ragni, D., & Casalino, D. (2021). Applications of the Multilayer Porous Medium Modeling Approach for Noise Mitigation. Journal of Aerospace Engineering, 34(6), 04021022. 5. Johnson, D. L., Koplik, J., & Daschen, R. (1987). Theory of dynamic permeability and tortuosity in fluid-saturated porous media. Journal of Fluid Mechanics, 176, 379. 6. Melon, M., Lafarge, D., Castagnède, B., & Brown, N. (1995). Measurement of tortuosity of anisotropic acoustic materials. Journal of Applied Physics, 78, 4929. 7. Allard, J. F. (1993). Propagation of sound in porous media. Elsevier Applied Science Publishers LTD. 8. Lafarge, D., Lemarinier, P., Allard, J. F., & Tarnow, V. (1997). Dynamic compressibility of air in porous structures at audible frequencies. Journal of the Acoustical Society of America, 102(4), 1995-1997. 9. Mahiou, A., Sellami, I., & Sadouki, M. (2021). Sensitivity of transmitted low-frequency ultrasound physical parameters describing a rigid porous material. Proceedings of Meetings on Acoustics, 45, 045004. 10. Sadouki, M., Mahiou, A., & Souna, N. (2022). Effect of acoustic low-frequency ultrasound parameters on the reflected signal from a rigid porous medium. Proceedings of Meetings on Acoustics, 50(1), 045002. 11. Sadouki, M. (2018). Experimental measurement of tortuosity, viscous and thermal characteristic lengths of rigid porous material via ultrasonic Global Journal of Researches in Engineering Volume XxXIII Issue I Version I 42 Year 2023 © 2023 Global Journals ( ) I Investigating the Effects of Physical Parameters on First and Second Reflected Waves in Air-Saturated Porous Media under Low-Frequency Ultrasound Excitation Table 2: Classification of the sensitivity of each parameter on the 1st and 2nd reflected signal Parameters ϕ α ∞ Λ ξ Λ ’ ξ ’ Influence on the 1st reflected signal +++ ++ + ~ ~~ ~~~ Influence on the 2nd reflected signal +++ + ++ + ~ ~~ +: Considerable ~: Weak