Design of Reflective-Type Muffler for Acoustic Noise Control in Space Missions: Numerical and Analytical Approach

Bahman Jahromi, Iman

doi:10.22034/jsst.2025.1523

Design of Reflective-Type Muffler for Acoustic Noise Control in Space Missions: Numerical and Analytical Approach

Document Type : Original Research Paper

Author

Iman Bahman Jahromi

Assistant Professor, Aerospace Research Institute, Ministry of Science, Research and Technology, Tehran, Iran

10.22034/jsst.2025.1523

Abstract

One of the most significant challenges in space missions is controlling the noise level within the cabin. Mufflers or silencers are employed to mitigate noise. In the present study, the performance of a basic reflective silencer is first investigated analytically and numerically in its simplest configuration. Based on the analytical evaluation of the base muffler, maximum performance occurs at odd multiples of π/2, while minimum performance is observed at integer multiples of π. Following the analytical analysis, extensions in the form of expanded tubes, designed based on the analytical findings, are added to the muffler. The performance of the reflective muffler is calculated using the sound transmission loss parameter and transfer matrix method, and the results are compared with numerical simulations. The findings reveal that while the numerical results generally align with the analytical predictions, discrepancies exist. Specifically, at frequencies above 1370 Hz, non-ideal effects are observed in the numerical results. As frequency increases, the acoustic wavefront inside the chamber deviates from a planar state, leading to reduced muffler efficiency at higher frequencies. Non-planar waves between the two extended tubes (with lengths L/2 and L/4) form at resonant frequencies of 1026 Hz and 1371 Hz. Although the emergence of non-planar waves disrupts muffler performance, the muffler with a single L/2 extension still outperforms the base muffler. Moreover, the configuration with two extended tubes (L/2 and L/4) exhibits the best performance among all tested mufflers.

Keywords

Reflective muffler

Extended-tube

Spacecraft acoustic

Transfer matrix

Acoustic isosurface

Subjects

Aerospace Engineering

Article Title Persian

طراحی مافلر انعکاسی جهت کنترل نوفه‌‌‌ی آکوستیک در مأموریت‌های فضایی: رویکرد تحلیلی-عددی

Author Persian

بهمن جهرمی

استادیار، پژوهشگاه هوافضا، وزارت علوم، تحقیقات و فناوری، تهران، ایران

Abstract Persian

یکی از مهم‌ترین چالش‌ها در مأموریت‌های فضایی کنترل سطح صوت درون محفظه می‌باشد. جهت کنترل نویز از مافلرها یا صدا خفه‌کن‌ها استفاده می‌شود. در پژوهش حاضر، در ابتدا کارایی یک صداخفه‌کن انعکاسی در ساده ترین حالت به صورت تحلیلی و عددی بررسی می‌شود. با توجه به بررسی تحلیلی مافلر پایه، بیشینه عملکرد در ضرائب فرد π/2 و کمینه عملکرد در ضرائب صحیح عدد π اتفاق می‌افتد. با توجه به تحلیل‌های انجام شده افزونه‌هایی از نوع لوله‌های گسترش یافته با طراحی به دست آمده در قسمت تحلیلی به آن افزوده می‌شود. کارایی مافلر انعکاسی با توجه به پارامتر اتلاف عبوری صوت و به کارگیری ماتریس انتقال محاسبه و با حل عددی مقایسه شده است. نتایج نشان می‌دهند که عملکرد به دست آمده از حل عددی، علیرغم تطابق کلی با نتایج تحلیلی، تفاوت‌هایی با آن دارد. به طور مشخص در فرکانس‌های بیشتر از 1370 هرتز، اثرات غیر اید‌ه‌آل در نتایج عددی دیده می‌شوند. با افزایش فرکانس، جبهه موج آکوستیک درون محفظه از حالت صفحه‌ای خارج می‌شود و این موضوع باعث اختلال در عملکرد مافلر با افزایش فرکانس‌ می‌شود. امواج غیر صفحه‌ای مابین دو لوله مافلر با دو لوله افزایشی به طول L/2 و L/4 در فرکانس تشدید 1026 هرتز و 1371 تشکیل شده‌اند. هرچند تشکیل امواج غیر صفحه‌ای در عملکرد مافلر اختلال ایجاد می‌کند، ولی با این وجود کماکان مافلر با یک لوله توسعه یافته L/2، عملکرد بهتری از مافلر پایه و مافلر با دو لوله توسعه یافته L/2 و L/4، بهترین عملکرد از بین مافلرهای بررسی شده را دارد.

Keywords Persian

مافلر انعکاسی

لوله‌ی گسترش یافته

آکوستیک فضاپیما

ماتریس انتقال

سطح هم‌فشار آکوستیک

[1] I. Dandaroy, S. R. Chu, J. Dornak, and C. S. Allen, "Development of acoustic mufflers for cabin noise reduction in Orion spacecraft," in INTER-NOISE and NOISE-CON Congress and Conference Proceedings, Washington, D.C., USA, 2021, pp. 568–576, https://doi.org/10.3397/IN-2021-1568.

[2] C. S. Allen, "Internal acoustics of the ISS and other spacecraft," in The Annual Conference of the Australian Acoustical Society, Perth, Australia, 2017, Paper JSC-CN-40479.

[3] C. Allen, "Quiet spacecraft cabin ventilation fan development: Motivation and context," in INTER-NOISE and NOISE-CON Congress and Conference Proceedings, Grand Rapids, Michigan, 2023, pp. 426–434, https://doi.org/10.3397/NC_2023_0065.

[4] J. R. Goodman, "Acoustics inside the space shuttle orbiter and the International Space Station," SAE, Tech. Rep. 2009-01-2247, 2009, https://doi.org/10.4271/2009-01-2247.

[5] J. R. Goodman and F. W. Grosveld, "Acoustics and noise control in space crew compartments," NASA, Rep. SP-2015-624, 2015.

[6] Z. Hu, C. Zhang, and L. Chen, "Simulation analysis of flow and acoustic characteristics of exhaust muffler of rolling rotor compressor," in Journal of Physics: Conference Series, 6th World Conference on Mechanical Engineering and Intelligent Manufacturing, Wuhan, China, vol. 2862, 2024, Art. no. 12026, https://doi.org/10.1088/1742-6596/2862/1/012026.

[7] D. Suwandi, J. Middelberg, K. P. Byrne, and N. J. Kessissoglou, "Predicting the acoustic performance of mufflers using transmission line theory," in ACOUSTICS 2005, Busselton, Australia, 2005, pp. 181–187.

[8] Y. Bai, Y. Chen, and J. Zheng, "Experimental study and acoustic characteristics analysis of defective-state Helmholtz-ring phononic crystal muffler," PREPRINT (Version 1) available at Research Square, 2024, https://doi.org/10.21203/rs.3.rs-4963361/v1.

[9] U. Kalita and M. Singh, "Optimization of reactive muffler through pressure acoustic analysis and Taguchi approach," Journal of the Brazilian Society of Mechanical Sciences and Engineering, vol. 45, 2023, Art. no. 98, https://doi.org/10.1007/s40430-023-04023-1.

[10] M. L. Munjal, Acoustic of Ducts and Mufflers, 2nd Ed., Jhon wiley Sons, 2014.

[11] R. Amuaku, E. A. Asante, A. Edward, and G. B. Gyamfi, "Effects of chamber perforations, inlet and outlet pipe diameter variations on transmission loss characteristics of a muffler using Comsol multiphysics," Advances in Applied Sciences, vol. 4, no. 6, pp. 104-109, 2019, https://doi.org/10.11648/j.aas.20190406.11.

[12] R. Gavit and K. Wani, "Muffler transmission loss optimization for a vehicle using genetic algorithm," in Smart Sensors Measurement and Instrumentation: Select Proceedings of CISCON 2021, S. Chokkadi and R. Bandyopadhyay, Eds. Springer Singapore, 2023, pp. 1–17, https://doi.org/10.1007/978-981-19-6913-3_1.

[13] B. Mohamad, J. Karoly, A. Zelentsov, and S. Amroune, "Investigation of perforated tube configuration effect on the performance of exhaust mufflers with mean flow based on three-dimensional analysis," Archives of Acoustic, vol. 46, no. 3, pp. 561–566, 2021, https://doi.org/10.24425/aoa.2021.138148.

[14] K. S. Oh, H. Chung, and J. H. Oh, "Topology optimization using reinforcement learning for designing the inside layout of a muffler," Available at SSRN, 2024, Art. no. 4953398, http://dx.doi.org/10.2139/ssrn.4953398.

[15] Y. C. Chang, M. C. Chiu, and M. R. Wu, "Acoustical simulation of a muffler internally inserted with an extended tube using the FEM," Journal of Information and Optimization Sciences, vol. 40, no. 1, pp. 47–62, 2019, https://doi.org/10.1080/02522667.2017.1413042.

[16] F. Rafique, J. H. Wu, C. R. Liu, and F. Ma, "Transmission loss analysis of a simple expansion chamber muffler with extended inlet and outlet combined with inhomogeneous micro-perforated panel (iMPP)," Applied Acoustics, vol. 194, 2022, Art. no. 108808, https://doi.org/10.1016/j.apacoust.2022.108808.

[17] E. Dokumaci, "Effect of sheared grazing mean flow on acoustic transmission in perforated pipe mufflers," Journal of Sound and Vibration, vol. 283, no. 3–5, pp. 645–663, 2005, https://doi.org/10.1016/j.jsv.2004.05.018.

[18] N. K. Vijayasree and M. L. Munjal, "On an integrated transfer matrix method for multiply connected mufflers," Journal of Sound and Vibration, vol. 331, no. 8, pp. 1926–1938, 2012, https://doi.org/10.1016/j.jsv.2011.12.003.