Sökning: "fractional step methods"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden fractional step methods.

1. 1. Adaptive finite element methods for multiphysics problems

   Författare :Fredrik Bengzon; Mats Larson; Harald van Brummelen; Umeå universitet; []
   Nyckelord :finite element methods; multiphysics; a posteriori error estimation; duality; adaptivity; discontinuous Galerkin; fractional step methods;

   Sammanfattning : In this thesis we develop and analyze the performance ofadaptive finite element methods for multiphysics problems. Inparticular, we propose a methodology for deriving computable errorestimates when solving unidirectionally coupled multiphysics problemsusing segregated finite element solvers. LÄS MER

3. 2. Simulation of Chemical Reactors

   Författare :Tommy Hertzberg; Avdelningen för kemiteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluid flow; chemical reactors; formox; fractional step; catalytic combustion; Spectral methods; self-adjoint operator; Chemical technology and engineering; Kemiteknik och kemisk teknologi;

   Sammanfattning : This thesis consists basically of two parts. They are, however, interrelated by the fact that both parts concerns modelling of catalytic reaction systems and also by the fact that in both parts, spectral methods are used for simulation. The first part describes the numerical treatment of the dispersion model. LÄS MER

4. 3. Nonlinear optimization approaches to H2-norm based LPV modelling and control

   Författare :Daniel Petersson; Lennart Ljung; Johan Löfberg; Henrik Sandberg; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Automatic control; Reglerteknik;

   Sammanfattning : To be able to analyze certain classes of non-linear systems, it is necessary to try to represent them as linear parameter varying systems or even as linear fractional representations. For linear parameter varying systems and linear fractional representations of systems there exists many advanced analysis methods such as IQC-analysis and μ-analysis. LÄS MER

5. 4. Development and Application of Uncertainty Analysis Approaches for MELCOR Simulations of Severe Accidents

   Författare :Wanhong Wang; Weimin Ma; Florian Fichot; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Severe accident; MELCOR; uncertainty analysis; Wilks’ method; Bootstrapped artificial neural network; deterministic sampling method; 95 95 tolerance limit.; Svåra haverier; MELCOR; osäkerhetsanalys; Wilks’ metod; artificiella neuronnät; deterministiska urvalsmetoder; 95 95-toleransgränser.;

   Sammanfattning : The contemporary needs in advancing safety analysis methods and the increasing stringency in light water reactor (LWR) safety in the post-Fukushima era require more advanced and systematical approaches for severe accident analyses. The best estimate plus uncertainty (BEPU) methods are among such approaches and have been widely used for deterministic safety analysis (DSA) of design basis accidents (DBAs). LÄS MER

7. 5. Domestic Heating with Solar Thermal : Studies of Technology in a Social Context and Social Components in Technical Studies

   Författare :Magdalena Lundh; Ewa Wäckelgård; Jan-Erik Nielsen; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; solar heating; solar energy; heating system; social components; market actors; interdisciplinary; heat storage; system solution; energy system; hot water; load profiles; socio-technical; Engineering physics; Teknisk fysik; teknisk fysik med inriktningen mikrosystemteknik; engineering science with specialization in microsystems technology;

   Sammanfattning : Research in solar heating has traditionally focused solely on increasing the system efficiency by improving the technical components. In this thesis the technical methodology and system boundaries are widened to connect the technical aspects with market actors that are highly influential on the implementation of solar technology. LÄS MER