This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Prediction of Muffler Radiated Noise for a Diesel Engine
Technical Paper
2011-26-0065
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Event:
SIAT 2011
Language:
English
Abstract
Exhaust noise is the major noise source for the automotive vehicle contributing to its interior as well as exterior noise. The Transmission Loss (TL), noise reduction, Insertion Loss (IL) and radiated noise are the major characteristics used to describe the performance of a muffler in an automotive exhaust system. Out of these characteristics, Insertion loss and exhaust radiated sound pressure levels plays a significant role in muffler design as it is a measure of true performance of muffler along with engine/vehicle and very much useful for the designers to compare different silencer configurations. In present work, the sound source is modelled by acoustic impedance and volume velocity of the engine. Since it is difficult to estimate the sound source impedance of the exhaust by measurements either with direct or indirect methods as both are prone to errors and difficult to implement, the empirical equations are used to define exhaust source, to have reasonable accuracy. In present study, the sound pressure at the exhaust opening is measured for different acoustic loads. The volume velocity is calculated backwards using the above measurement result and the numerical model of acoustic loads used. Estimation of Sound Pressure Level (SPL) at the exhaust opening has become possible by using source acoustic impedance and volume velocity, as the boundary conditions of the exhaust system model. Comparison of predicted and measured SPL is also presented for different engine speeds under full load condition.
Recommended Content
| Technical Paper | Dynamic Comprehensive Performance of Mufflers under Different Vehicle Running Conditions |
| Technical Paper | A Time-Domain Approach for Multi-Pass Perforated Tube Silencers |
| Technical Paper | A Unique Dual-Mode Muffler |
Authors
Citation
Yadav, P., Gaikwad, A., Kunde, S., and Karanth, N., "Prediction of Muffler Radiated Noise for a Diesel Engine," SAE Technical Paper 2011-26-0065, 2011, https://doi.org/10.4271/2011-26-0065.Also In
References
- Munjal, M L “Acoustics of Ducts and Mufflers” John Wiley 1987
- Sathyanarayana, Y Munjal, M L “A Hybrid Approach for Aero Acoustic Analysis of the Engine Exhaust System” Applied Acoustics 60 425 450 2000
- Prasad, M G Crocker, M J “On the Measurement of the Internal Source Impedance of a Multi Cylinder Engine Exhaust System” Journal of Sound and Vibration 90 491 508 1983
- Prasad, M G “A Four Load Method for Evaluation of Acoustical Source Impedance in a Duct” Journal of Sound and Vibration 114 347 356 1987
- Boden, H “The Multiple Load Method for Measuring the Source Characteristics of the Time Variant Sources” 148 437 453 1991
- Harrison, M F Davies, P O A L “Rapid Prediction of vehicle intake exhaust Radiated Noise” IMech E C487/019/94 183 190 1994
- Callow, G D Peat, K S “Insertion Loss of Engine Inflow and Exhaust Silencers” I Mech. E C19/88 1988
- Fairbrother, R Boden, H Glav, R “Linear Acoustic Exhaust System Simulation Using Source Data from Linear Simulation” SAE Paper No. 2005-01-2358 2005
- Boden, H Tonsa, M Fairbrother, R 2004 “On Extraction of IC-Engine Linear Acoustic Source Data from Non-linear Simulations” Proceedings of the 11th International Congress on Sound and Vibration 2004
- Hota, R N Munjal, M L “Approximate Empirical Expressions for the Aero Acoustics Source Strength Level of the Exhaust System of the Compression Ignition Engines” Aeroacoustics 7 3&4 2008
- Kido, Hideki et al. “Modeling the Source of Intake and Predicting Intake Sound Pressure Levels for a Motorcycle” SAE Paper No. 2003-32-0058 2003
- LMS VIRTUAL LAB Help Manual
- Munjal, M L Doige, A G “Theory of Two Source Location Method for Direct Experimental Evaluation of Four Pole Parameters of Aero Acoustic Element,” J. Sound and Vibration . 141 2 323 333 1990