Sökning: "Acoustic analogies"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Acoustic analogies.

  1. 1. Computational Aeroacoustics Based on Large Eddy Simulation and Acoustic Analogies

    Författare :Mihai Mihaescu; Laszlo Fuchs; Strömningsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mechanical engineering; hydraulics; plasma; Technological sciences; Teknik; fluiddynamik; plasmas; Gaser; fluid dynamics; Gases; Inhomogeneous Wave Equation; Acoustic Boundary Conditions; Acoustic Source Terms; LES; Computational Aeroacoustics; Turbulent Flows; vacuum technology; vibration and acoustic engineering; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik; Computational Aeroacoustics;

    Sammanfattning : The thesis presents a numerical method developed by the author and its applications for computing the generated sound by an unsteady flow field and its propagation. The full equations of motion for compressible and unsteady flows describe both flow field and sound generation and propagation. LÄS MER

  3. 2. Turbomachinery Aeroacoustic Calculations using Nonlinear Methods

    Författare :Martin Olausson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nonlinear; CFD; Time Spectral; CAA; Ffowcs-Williams Hawkings; Broadband; Time lag; Computational Aeroacoustics; Fan-Noise; Rotor-Stator interaction; Buffer layer; Oscillating sphere; Newton-GMRES; Computational Fluid Dynamics; Acoustic analogies; Sponge; Counter-Rotating Propfan; Harmonic Balance Technique; Tone; FWH; Chorochronic periodicity; Hybrid RANS LES;

    Sammanfattning : Noise regulations for aircraft that fly over populated areas are becoming continuously stricter. This in combination with increasing computational capabilities has boosted interest in aeroacoustic computations in the aerospace industry. LÄS MER

  4. 3. Aerodynamic and Aeroacoustic Analysis of a Multi-Element Airfoil using Hybrid RANS/LES Modeling Approaches

    Författare :Bastian Nebenführ; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ffowcs-Williams and Hawkings; HYB0; noise; hybrid RANS LES; multi-element airfoil; CAA; Kirchhoff; Curle; high-lift;

    Sammanfattning : Global hybrid RANS/LES simulations were used for computing the turbulent flow around a three-element airfoil. Based on the results of the flow computations, a comprehensive analysis of the flow properties was performed. LÄS MER

  5. 4. Modelling the Production and Propagation of Sound in Individual Human Vocal Tracts

    Författare :Lukas Schickhofer; Mihai Mihaescu; Anders Dahlkild; Manfred Kaltenbacher; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Biomechanics; Vocal Tract Acoustics; Numerical Flow Simulation; Fluid-Structure Interaction;

    Sammanfattning : Voice generation and the expression through speech are of vital importance for communication. The human upper airways are the origin of the process of speech production, which involves a modulation of the periodically pulsed pressure from the lungs by the vocal tract volume. LÄS MER

  7. 5. Microstructure of spray dried particles at different scales of drying

    Författare :Marine Nuzzo; Livsmedelsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; microstructure; morphology; confocal Raman microscopy; phase segregation; spray drying;

    Sammanfattning : Spray drying is a preferred method to produce dry powder of thermally sensitive materials such as food and pharmaceuticals. Drying conditions and formulation determine primary properties such as morphology and composition that finally provide functionality such as dissolution, encapsulation and flowability. LÄS MER