Search for dissertations about: "Acoustic solvers"

Showing result 1 - 5 of 8 swedish dissertations containing the words Acoustic solvers.

  2. 1. Numerics of Elastic and Acoustic Wave Motion

    Author : Kristoffer Virta; Gunilla Kreiss; Anders Petersson; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; finite differences; stability; high order accuracy; elastic wave equation; acoustic wave equation; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Abstract : The elastic wave equation describes the propagation of elastic disturbances produced by seismic events in the Earth or vibrations in plates and beams. The acoustic wave equation governs the propagation of sound. READ MORE

  4. 2. Thermo-Acoustic Properties in Combustion Chambers

    Author : Guillaume Jourdain; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mode Stability Analysis; Computational Aeroacoustics; Screech mode; Arnoldi s Method; Buzz mode; Afterburner; Gas turbine combustor; Combustion instabilities;

    Abstract : Design and analysis methods for gas turbine combustors or afterburners have to be improved in particular regarding the prediction of combustion instabilites. A methodology, which combines the use of a linearized flow solver and an Arnoldi algorithm performing the eigenmode extraction procedure, resolves eigenmodes which are candidates to these instabilities. READ MORE

  5. 3. Prediction of Thermo-Acoustic Properties in Combustion Chambers

    Author : Guillaume Jourdain; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : Design and analysis methods for gas turbine combustors or afterburners need to be improved in particular regarding the prediction of combustion instabilities. A methodology, which combines the use of a linearized flow solver and the Arnoldi algorithm for eigenmode extraction, resolves eigenmodes which are candidates to these instabilities. READ MORE

  6. 4. Numerical Modelling of Fuel Sprays

    Author : Christer Bergström; Strömningsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; vibration and acoustic engineering; vacuum technology; hydraulics; Mechanical engineering; Gas turbine.; Temperature fluctuations. Diesel engine; Counter rotating Vortex Pair; CVP; Large Eddy Simulation; Droplet Evaporation; Turbulent flows; LES; Spray; Modelling; Break-up; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik; Carbochemistry; petrochemistry; fuels and explosives technology; Petrokemi; bränslen; sprängämnen;

    Abstract : The way the fuel is introduced into the combustion chamber is one of the most important parameters for the power output and the generation of emissions in the combustion of liquid fuels. The interaction beween the turbulent gas flow field and the liquid fuel droplets, the vaporisation of them and the mixing of the gaseous fuel with the ambient air that are vital parameters in the combustion process. READ MORE

  7. 5. Adaptive finite element/difference methods for time-dependent inverse scattering problems

    Author : Larisa Beilina; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : In this thesis we develop adaptive hybrid finite element/difference methods for inverse time-domain acoustic and elastic scattering, where we seek to find the location and form of a (small) unknown object inside a large homogeneous body from measured wave-reflection data. We formulate the inverse problem as an optimal control problem, where we seek to reconstruct unknown material coefficients with best least squares wave fit to data. READ MORE