Sökning: "akustik"

Visar resultat 36 - 40 av 1066 avhandlingar innehållade ordet akustik.

1. 36. Experimental and multivariate analysis methods for sound quality evaluation of diesel engines

   Författare :Örjan Johansson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknisk akustik; Engineering Acoustics;

   Sammanfattning : Noise control and sound quality analysis are important, since noise has been registered to be a predominant factor in stress and a source of great annoyance. Traffic noise is a problem and a major part of this noise comes from heavy vehicles. LÄS MER

3. 37. Crankshaft speed measurements and analysis for control and diagnostics of diesel engines

   Författare :Roger Johnsson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknisk akustik; Engineering Acoustics;

   Sammanfattning : The increasing demands from governments on the engine manufactures to lower the fuel consumption, lower the exhaust emissions and to reduce the noise have lead to an intensive research in the combustion process. Measurement of the combustion process inside the cylinder is only suitable in laboratory environment due to a number of limitations; the pressure transducer needed to measure the pressure is expensive, difficult to mount in the cylinder and has a limited lifetime that is much shorter than the engine's lifetime. LÄS MER

4. 38. Frequency Domain Linearized Navier-Stokes Equations Methods for Low Mach Number Internal Aeroacoustics

   Författare :Axel Kierkegaard; Gunill Efraimsson; Christophe Schram; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustics; Akustik;

   Sammanfattning : Traffic is a major source of environmental noise in modern day's society. As a result, the development of new vehicles are subject to heavy governmental legislations. The major noise sources on common road vehicles are engine noise, transmission noise, tire noise and, at high speeds, wind noise. LÄS MER

5. 39. Numerical Investigations of Generation and Propagation of Sound Waves in Low Mach Number Internal Flows

   Författare :Axel Kierkegaard; Gunilla Efraimsson; Mats Åbom; Wolfgang Polifke; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustics; Akustik;

   Sammanfattning : Traffic is a major source of environmental noise in modern day society. Subsequently, development of new vehicles are subject to heavy governmental legislations. The major noise sources on common road vehicles are engine noise, transmission noise, tire noise and, at high speeds, wind noise. LÄS MER

7. 40. IC-engine intake noise predictions based on linear acoustics

   Författare :Magnus Knutsson; Mats Åbom; Antonio Torregrosa; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustics; Akustik;

   Sammanfattning : Shorter product development cycles, densely packed engine compartments and intensified noise legislation increase the need for accurate predictions of IC-engine air intake noise at early stages. The urgent focus on the increasing CO2 emissions and the efficiency of IC-engines, as well as new techniques such as homogeneous charge compression ignition (HCCI) might worsen the noise situation. LÄS MER