Sökning: "sound radiation"

Visar resultat 6 - 10 av 46 avhandlingar innehållade orden sound radiation.

  1. 6. Active Junction Control and Piezoelectric Hybrid Damping for Improving the Acoustic Performance of Lightweight Structures

    Författare :Jonas Svensson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hybrid passive-active control; Piezoelectric shunt damping; Sound radiation; Active junction control;

    Sammanfattning : Weight reduction is a key factor in lowering the fuel consumption and thereby the greenhouse emissions from vehicles. However, reducing the weight normally results in a deterioration of the acoustic performance. Thus, the purpose of this thesis is to investigate damping treatments for lightweight vehicle panels. LÄS MER

  3. 7. The influence of modelling parameters on the simulation of car tyre rolling losses and rolling noise

    Författare :Carsten Hoever; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rolling resistance; modelling parameters; parameter study; radiation; tyre road noise; tyres; tyre road interaction; waveguide finite element;

    Sammanfattning : Due to legislative changes within the EU there is an increased demand for improvement in car tyre rolling resistance and noise generation. Yet, apart from empirical data based on measurements, there is little information concerning the relationship between rolling resistance and rolling noise generation. LÄS MER

  4. 8. Sound Field Design for Transducer Array-Based Acoustic Levitation

    Författare :Carl Andersson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nonlinear Acoustics; Sound Field Design; Transducer Arrays; Acoustic Levitation; Numerical Optimization;

    Sammanfattning : Acoustic levitation is a technique where sound waves are used to hold an object at a designated position, suspending it against other external forces and keeping it stable in the desired position. Transducer arrays are an arrangement of many loudspeaker elements, tuned such that the array creates a sound field that is too complicated for the individual elements to produce on their own. LÄS MER

  5. 9. Prediction of sound radiation from vibration slender bodies by efficient integral methods

    Författare :Fredrik Grönberg; KTH; []
    Nyckelord :;

    Sammanfattning : .... LÄS MER

  7. 10. Sound and vibrations in structures with air enclosures

    Författare :Anna Runnemalm; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Experimentell mekanik; Experimental Mechanics;

    Sammanfattning : Vibrations in thin shell structures and sound fields in enclosures are investigated as well as the interaction between such structures and the enclosed sound field. Optical, non-contacting methods as TV holography, shearography and laser scanning vibrometry are used to investigate vibrations of thin shell structures with air enclosures. LÄS MER