Search for dissertations about: "Jan Lundquist"

Found 4 swedish dissertations containing the words Jan Lundquist.

  2. 1. High order summation-by-parts methods in time and space

    Author : Tomas Lundquist; Jan Nordström; Peter Eliasson; David A. Kopriva; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; summation-by-parts; time integration; stiff problems; weak initial conditions; high order methods; simultaneous-approximation-term; finite difference; discontinuous Galerkin; spectral methods; conservation; energy stability; complex geometries; non-conforming grid interfaces; interpolation;

    Abstract : This thesis develops the methodology for solving initial boundary value problems with the use of summation-by-parts discretizations. The combination of high orders of accuracy and a systematic approach to construct provably stable boundary and interface procedures makes this methodology especially suitable for scientific computations with high demands on efficiency and robustness. READ MORE

  4. 2. Managing uncertainties through efficient calculation of transients and harmonic propagation in power systems

    Author : Oscar Lennerhag; Math Bollen; Jan Lundquist; David Thomas; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Overvoltages; harmonics; uncertainties; stochastic methods; Electric Power Engineering; Elkraftteknik;

    Abstract : The electric power system is undergoing changes including large-scale introduction of renewable energy sources together with HVDC/FACTS, changes in the network such as increased amount of high voltage cables, industrial electrification, and changes in the load composition. These changes will impact the system in different ways and lead to challenges that must be addressed to facilitate planning, dimensioning, and operation of the system in a secure and economical way. READ MORE

  5. 3. Till stratigraphy and ice recession in the Bothnian Bay

    Author : Thomas Andrén; Jan Lundquist; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Morän;

    Abstract : .... READ MORE

  6. 4. Pressure driven instabilities in the reversed-field pinch : numerical and theoretical studies

    Author : Ahmed Akram Mirza; Jan Scheffel; Roberto Paccagnella; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Fusion plasma; thermonuclear; Reversed-field pinch; resistive MHD; resistive g modes; thermal conduction; the boundary value theory;

    Abstract : According to classical linearized resistive magnetohydrodynamics theory, pressuredriven modes are unstable in the reversed-field pinch (RFP) due to unfavorable magnetic field line curvature. The result is based on the assumption of an adiabatic energy equation where anisotropic thermal conduction effects are ignored as compared to convection and compression. READ MORE