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Visar resultat 1 - 5 av 72 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Multiphysics Characterization of SiC Power Modules

   Författare :Yafan Zhang; Hans-Peter Nee Nee; Mietek Bakowski; Ilja Belov; Alberto Castellazzi; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Silicon carbide; power electronics; power electronics packaging; experiment; modeling and simulation; computational fluid dynamics; finite element analysis; multiphysics; Kiselkarbid; effektelektronik; effektelektronisk kapsling; experiment; modellering och simulering; flödesdynamisk numerisk modellering; finit-element-analys; multifysik; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : This thesis proposes several novel silicon carbide power module design concepts. The goal has been to address the problems with the present designs. The electrical, thermal, and thermomechanical performances of the demonstrators have been evaluated along with presentations of methodologies of experimental and numerical characterizations. LÄS MER

3. 2. 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

4. 3. Finite element methods for multiscale/multiphysics problems

   Författare :Robert Söderlund; Mats Larson; Victor Ginting; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; finite element methods; variational multiscale methods; Galerkin; convergence analysis; multiphysics; a posteriori error estimation; duality; adaptivity; Mathematical statistics; Matematisk statistik; Mathematical Statistics; matematisk statistik;

   Sammanfattning : In this thesis we focus on multiscale and multiphysics problems. We derive a posteriori error estimates for a one way coupled multiphysics problem, using the dual weighted residual method. LÄS MER

5. 4. Macroscopic modelling of coupled multiphysics in swelling cellulose based materials

   Författare :Marcus Alexandersson; Hållfasthetslära; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; multiphysics; multiphase flow; mixture theory; porous media; cellulose based materials; paperboard;

   Sammanfattning : Paperboard has been the basis for packaging materials used to aseptically store and protect food and beverages for a long time. To ensure that there are no bacteria that can spoil the product, sterilizing treatments are made. LÄS MER

7. 5. Multiphysics modelling of PEM fuel cells - with reacting transport phenomena at micro and macroscales

   Författare :Munir Khan; Värmeöverföring; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; macroscale; PEM fuel cells; CFD; microscale; multiphysics; multiphase; anisotropy;

   Sammanfattning : This thesis presents numerical simulations of reacting transport phenomena in polymer electrolyte membrane (PEM) fuel cells. Broadly, the presented work is subdivided into macro and microscale simulations. LÄS MER