SCOPE FOR ACTIVE NOISE ABATEMENT IN VEHICLE DIESEL ENGINES

MOEGLICHKEITEN AKTIVER LAERMBEKAEMPFUNG AN FAHRZEUG-DIESELMOTOREN

The author describes recent research carried out by the Sauser company to meet the 1974 Swiss regulations that require compliance with an accelerated passing test; comparative measurements, made by the subtractive method show that 90 per cent of the sound energy is emitted by the engine exhaust system and the cooling fan. Exhaust systems can be improved by a more effective silencer and by better damping of the surface vibrations of the silencer and pipelines involved. Fan noise can be reduced by using it only when a full cooling output is required. Engine noise starts at the combustion point and is then mainly a solid-borne transmission leading to free damped vibrations of the engine compartment causing the perceived air-borne noise. Engine casing, oil sump, air charge line or suction pump, flywheel and clutch casing accounts for 98 per cent of the engine noise. Measures investigated which had to be suitable for mass production, included the fitting of cross bearing rib stiffness on the side walls and a partly double walled and partly ribbed clutch housing. An elastic sump mounting and special cover for the air suction pipe were included in the package which reduced total engine noise by 3.5 to 4 bd.(Author/TRRL) 3.5 to 4 bd. (Author/TRRL)

• Supplemental Notes:
  • This report was originally published in German in the Proceedings of the 17th International Congress, Budapest 4-10 June 1978, Volume 3, Federation Internationale des Societes d'Ingenieurs des Techniques de l'Automobile, Paris.
• Corporate Authors:

  Transport and Road Research Laboratory (TRRL)

  Wokingham, Berkshire  United Kingdom 
• Authors:
  • Summerauer, I
  • Boesch, N
• Publication Date: 0

Media Info

• Features: Figures; Photos; References;
• Pagination: 20 p.
• Serial:
  • TRRL LABORATORY REPORT
  • Issue Number: 3133
  • Publisher: Transport and Road Research Laboratory (TRRL)

Subject/Index Terms

• TRT Terms: Conferences; Cooling; Damping (Physics); Diesel engines; Emission control systems; Engines; Equipment; Exhaust gases; Exhaust pipes; Fans; Mechanical acceleration; Mufflers; Noise; Noise control; Sound; Translations; Vibration
• Uncontrolled Terms: Noise reduction; Reduction (Decrease)
• Geographic Terms: Hungary
• Old TRIS Terms: Engine noise
• ITRD Terms: 5405: Acceleration; 8525: Conference; 6711: Cooling (mater); 5559: Damping; 9009: Decrease; 1314: Diesel engine; 3674: Equipment; 1384: Exhaust pipe; 8043: Hungary; 1395: Silencer; 6748: Sound; 8538: Translation; 5558: Vibration
• Subject Areas: Environment; Highways; Vehicles and Equipment; I91: Vehicle Design and Safety;

Filing Info

• Accession Number: 00451057
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Aug 27 2004 9:57PM