Sökning: "air cavity resonances"

Hittade 4 avhandlingar innehållade orden air cavity resonances.

  1. 1. The influence of tyre air cavities on vehicle acoustics

    Författare :Èric Torra i Fernàndez; Anders Nilsson; Wim Desmet; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; acoustics; tyre-road noise; tyre; air cavity resonances; interior noise; aluminium foams; Acoustics; Akustik;

    Sammanfattning : The tonal character of the low frequency internal noise in cars is often due to energy transmission through the tyre at the first few eigenfrequencies of the air cavity of the tyre. The first acoustic mode in the air cavity of a typical stationary car tyre is approximately 224 Hz. LÄS MER

  3. 2. Continuous-filtering Vernier spectroscopy

    Författare :Chuang Lu; Aleksandra Foltynowicz; Ove Axner; Wei Ren; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spectroscopy; spectrometer; laser; optical frequency comb; optical cavity; NIR; MIR; flame; robust; time resolution; spectrum; fysik; Physics;

    Sammanfattning : Continuous-filtering Vernier spectroscopy (CF-VS) is a laser-based detection technique that combines the broad spectral coverage of an optical frequency comb (OFC) with the enhanced interaction length provided by an optical cavity. The resonances of the cavity filter the OFC to a small group of comb modes that probe the transitions of the species present in the cavity. LÄS MER

  4. 3. Dispersion Engineering : Negative Refraction and Designed Surface Plasmons in Periodic Structures

    Författare :Zhichao Ruan; Min Qiu; Henri Benisty; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; photonic crystal; dispersion property; negative refraction; surface plasmon polariton; designed surface plasmon; negative index material; layer-KKR method; finite-difference time-domain method; plane wave method; subwavelength imaging; open cavity; enhanced transmission; slowing light; Photonics; Fotonik;

    Sammanfattning : The dispersion property of periodic structures is a hot research topic in the last decade. By exploiting dispersion properties, one can manipulate the propagation of electromagnetic waves, and produce effects that do not exist in conventional materials. LÄS MER

  5. 4. On the improvement of low frequency sound insulation in wooden buildings

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

    Sammanfattning : Wooden multi-family residential houses continue to gain in popularity. Compared to concrete, wooden constructions have low mass and are subject to relatively poor sound insulation at low frequencies. LÄS MER