This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Catalyst and DPF Acoustic Transmission Loss Benchmark Study
Technical Paper
2017-01-1798
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
The ability to accurately predict exhaust system acoustics, including transmission loss (TL) and tailpipe noise, based on CAD geometry has long been a requirement of most OEM’s and Tier 1 exhaust suppliers. Correlation to measurement data has been problematic under various operating conditions, including flow. This study was undertaken to develop robust modelling technique, ensuring sensible correlation between the 1-D models and test data. Ford use Ricardo WAVE as one of their 1-D NVH tools, which was chosen for the purpose of this benchmark study. The most commonly used metrics for evaluating the acoustical performance of mufflers are insertion loss (IL), TL, and noise reduction (NR). TL is often the first step of analysis, since it represents the inherent capability of the muffler to attenuate sound if both the source and termination are assumed to be anechoic. It can also be reliably measured and numerically simulated without having to connect to an engine. For the purpose of software validation, TL benchmarking should be the first step. This study focused around two key exhaust components: Catalysts and Diesel Particulate Filter (DPF), with TL measurements collected for validation purposes. These measurements were compared to simulation data to validate Ricardo WAVE models that directly reflected the test set up. Differences were identified, and model sensitivities studies conducted resulting in revised modeling recommendations for CAT’s and DPF’s. This resulted in more accurate modelling of TL before any hardware is procured.
Recommended Content
Authors
Citation
Navratil, J., Seeley, W., Wang, P., and Siravara, S., "Catalyst and DPF Acoustic Transmission Loss Benchmark Study," SAE Technical Paper 2017-01-1798, 2017, https://doi.org/10.4271/2017-01-1798.Also In
References
- "Regulation (EU) No 540/2014 of the European Parliament and of the Council of 16 April 2014 on the Sound Level of Motor Vehicles, " Official Journal of the European Union, 27 May 2014.
- Kim, U., Maunder, M., Grant, P., and Mawdsley, D., "Developing a Car to Meet New Pass-By Noise Requirements using Simulation and Testing," SAE Technical Paper 2015-01-2319, 2015, doi:10.4271/2015-01-2319.
- Mori, T., Takaoka, A., and Maunder, M., "Achieving a Vehicle Level Sound Quality Target by a Cascade to System Level Noise and Vibration Targets," SAE Technical Paper 2005-01-2394, 2005, doi:10.4271/2005-01-2394.
- Meduri, S., Sundaram, V., and Kumar S, S., "A Novel Approach to Optimize the Resonators for Air Induction System," SAE Technical Paper 2016-01-1320, 2016, doi:10.4271/2016-01-1320.
- Elnerm, Y, "Acoustic Modeling and Testing of Exhaust and Intake System Components," KTH Thesis in Technical Acoustics Stockholm, Sweden, 2011, ISSN 1651-7660
- Zhang, Y. and Herrin, D., "A Comparison of the Transfer and Scattering Matrix Approaches for Determining Muffler Transmission Loss using the Two Load Method," SAE Technical Paper 2015-01-2308, 2015, doi:10.4271/2015-01-2308.