AN ANALYTICAL MODEL FOR EXHAUST SYSTEM DESIGN

An analytical model has been developed that provides a valuable addition to the design and evaluation of practical exhaust systems. Exhaust system elements may be considered as reactive, resistive, or combination units. Reactive elements reduce energy transmission through a change in impedance that results in acoustic energy being reflected back to the source. Resistive or dissipative elements reduce energy transmission through actual energy dissipation in the element, typically accomplished using fibrous materials such as fiberglass or steel wool. The analytical model's focus is on reactive element design, although many of the ideas can be applied to resistive elements. The method developed by Alfredson and Davies assumes insentropic area contractions and adiabatic area expansions. Their approach has been modified for ease of use and to include conditions not originally considered. The revised model analyzes each element on a section-by-section basis to increase flexibility in analysis and to include a different temperature for each section. More complex elements like plug sections, pass sections, and reversing chambers are also modeled. Effects of higher-order modes can be calculated with the model, and source impedance effects can be simulated to produce insertion loss calculations. Model application provides insight into obtaining additional insertion loss without a corresponding increase in muffler volume. The model can be used for specific design problems and in general parameter studies to maximize exhaust system attenuation within a given volume.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/01487191
• Supplemental Notes:
  • Presented at SAE Earthmoving Industry Conference, Peoria, Illinois, 10-12 April 1978.
• Corporate Authors:

  Society of Automotive Engineers (SAE)

  400 Commonwealth Drive
  Warrendale, PA  United States  15096
• Authors:
  • Eriksson, L J
• Publication Date: 1978

Media Info

• Features: References;
• Pagination: 14 p.
• Serial:
  • SAE Technical Paper
  • Publisher: Society of Automotive Engineers (SAE)
  • ISSN: 0148-7191
  • EISSN: 2688-3627
  • Serial URL: http://papers.sae.org/

Subject/Index Terms

• TRT Terms: Design; Emission control systems; Exhaust gases; Mathematical models; Mufflers
• Subject Areas: Design; Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 00395893
• Record Type: Publication
• Source Agency: National Highway Traffic Safety Administration
• Report/Paper Numbers: SAE 780472, HS-025 507U
• Files: HSL, USDOT
• Created Date: Jul 31 1985 12:00AM