Sökning: "Arnoldi"

Visar resultat 6 - 10 av 20 avhandlingar innehållade ordet Arnoldi.

  1. 6. Analysis and control of transitional shear flows using global modes

    Författare :Shervin Bagheri; Dan Henningson; Alessandro Bottaro; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fluid mechanics; flow control; hydrodynamic stability; global modes; jet in crossflow; flat-plate boundary layer; laminar-turbulent transition; Arnoldi method; Koopman modes; balanced truncation; direct numerical simulations.; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : In this thesis direct numerical simulations are used to investigate two phenomenain shear flows: laminar-turbulent transition over a flat plate and periodicvortex shedding induced by a jet in cross flow. The emphasis is on understanding and controlling the flow dynamics using tools from dynamical systems and control theory. LÄS MER

  3. 7. Model Order Reduction with Rational Krylov Methods

    Författare :K. Henrik A. Olsson; Axel Ruhe; Volker Mehrmann; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Model order reduction; dual rational Arnoldi; rational Krylov; moment matching; eigenvalue computation; stability analysis; heat exchanger model; Numerical analysis; Numerisk analys;

    Sammanfattning : Rational Krylov methods for model order reduction are studied. A dual rational Arnoldi method for model order reduction and a rational Krylov method for model order reduction and eigenvalue computation have been implemented. It is shown how to deflate redundant or unwanted vectors and how to obtain moment matching. LÄS MER

  4. 8. Speciminis literarii, de meritis et fatis Johannis et Arnoldi, Messeniorum, pars prior, quam consent. ampl. fac. phil. acad. Ups. Olavus Celsius, fil. ... et Johannes Tillman, Ostro-Gothus, publico bonorum examini modeste submittunt; in auditor. Carol. maj. d. 25. Apr. ann. MDCCXLI. Horis ante meridiem solitis

    Författare :Olof Celsius; Johan Tillman; Olof Celsius; Uppsala universitet; []
    Nyckelord :HUMANIORA; HUMANITIES;

    Sammanfattning : .... LÄS MER

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

    Författare :Guillaume Jourdain; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : 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. LÄS MER

  7. 10. Developing Computational Tools for Modern Aeroacoustic Research

    Författare :Mirela Caraeni; Strömningsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Thermal engineering; unstructured mesh; termoacoustic; acoustic; cfd; applied thermodynamics; Termisk teknik; termodynamik;

    Sammanfattning : The thesis presents the author s research on numerical methods for Com-putational Aeroacoustics and the development of computational tools with direct applicability in industry. The designers in the gas-turbine industry, require accurate methods for predicting the onset and the frequencies of dangerous (pressure) oscillations, like the ones which typically occur in Lean Premixed Pre-vaporized (LPP) combustors. LÄS MER