Sökning: "vakuumteknik"

Visar resultat 11 - 15 av 45 avhandlingar innehållade ordet vakuumteknik.

  1. 11. Numerical Modelling of Dynamics of Light Porous Materials

    Författare :Peter Göransson; Teknisk akustik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mechanical engineering; glass fibre; foam; material characterisation; elasto-acoustic; fluid-structure interaction; finite element; Biot; porous material; hydraulics; vacuum technology; vibration and acoustic engineering; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik;

    Sammanfattning : Porous materials are among the most commonly used materials for noise and vibration reduction in modern transportation vehicles. To design, industrially relevant, weight and cost effective noise and vibration measures, there is a need for general prediction models capable of representing the elasto-acoustic behaviour of such materials. LÄS MER

  2. 12. Large Eddy Simulations of Separated Compressible Flows around Wing Sections

    Författare :Jörgen Held; Strömningsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbulence; subgrid-scale; shock-boundary layer interaction; wing section; transonic; subsonic; compressible; separated; Large eddy simulation; LES; PVM; Mechanical engineering; hydraulics; vacuum technology; vibration and acoustic engineering; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik;

    Sammanfattning : This thesis concerns numerical calculations of compressible separated flows, with and without shocks, around wing sections using Large Eddy Simulations (LES). The considered geometries are the NACA 0012 wing section and the ONERA AT15A wing section. LÄS MER

  3. 13. Acoustical properties of earplugs

    Författare :Per Hiselius; Teknisk akustik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik; vibration and acoustic engineering; vacuum technology; hydraulics; Mechanical engineering; acoustic modelling; objective measurement; insertion loss; earplugs; HPE; HPD; hearing protectors; Two-Port; Four-Pole; attenuation; electro acoustics; acoustics;

    Sammanfattning : In this study an experimental setup for measurements of high impedance objects in ducts, yielding the acoustical Two-Port properties of the object, is applied to earplugs. A frequently used experimental setup for measuring objective acoustical properties of earplugs is that of artificial ears. Great effort is spent on duplicating the human ear. LÄS MER

  4. 14. Characterization of the Homogeneous Charge Compression Ignition Combustion Process

    Författare :Anders Hultqvist; Förbränningsmotorer; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; akustik; Motors and propulsion systems; Motorer; framdrivningssystem; Termisk teknik; termodynamik; Thermal engineering; applied thermodynamics; vakuumteknik; hydraulik; Maskinteknik; vibration and acoustic engineering; hydraulics; vacuum technology; ATAC; Mechanical engineering; MK; CAI; TS; MULDIC; PREDIC; HCCI; fuel tracer; combustion; injection; direct; port; engine; LDV; LIF; PLIF; vibrationer;

    Sammanfattning : The main objective of this project was to characterize the HCCI combustion process. Central parts in the project were the progress of the HCCI combustion process, the influence of charge homogeneity on the combustion process and sources of UHC and CO emissions in HCCI combustion. LÄS MER

  5. 15. Modeling of coupled thermoplasticity at finite strains

    Författare :Paul Håkansson; Hållfasthetslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mechanical engineering; hydraulics; vacuum technology; vibration and acoustic engineering; Maskinteknik; Heat generation; Phase transformation; Void growth; Thermoplasticity; hydraulik; vakuumteknik; vibrationer; akustik; Crystal plasticity; Finite element;

    Sammanfattning : In this thesis, models for simulation of inelastic phenomena, such as plastic anisotropy, texture evolution, void growth and phase transformation are presented. Special emphasized is put on the modeling of heat generation due to plastic work. All models are formulated within a thermodynamic framework that allows large deformations. LÄS MER