Search for dissertations about: "Drag reduction"

Showing result 21 - 25 of 56 swedish dissertations containing the words Drag reduction.

  2. 21. District Heating Substations. Performance, Operation and Design

    Author : Janusz Wollerstrand; Energihushållning; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; extreme value; heater; sizing; domestic hot water; drag reducing additives; microbial fouling; heat exchanger fouling; simulation; design; performance; District heating; substation; Energy research; Energiforskning;

    Abstract : This thesis work is concerned with the efficient layout and operation of substations, i.e. those district heating (DH) system units which connect the network and internal building heating systems, such as radiator heating systems and domestic hot water distribution networks. READ MORE

  4. 22. Limiting processes in anion-exchange membrane fuel cells

    Author : Henrik Grimler; Göran Lindbergh; Rakel Wreland Lindström; Carina Lagergren; Marc Secanell; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; anion-exchange membrane fuel cell; hydrogen oxidation reaction; oxygen reduction reaction; water transport; physics-based modelling; Chemical Engineering; Kemiteknik;

    Abstract : Fuel cells allow for converting chemical energy stored in hydrogen into electrical energy, with only heat and water as by-products. In a sustainable energy society, hydrogen may play an important role due to its ability to act both as an energy carrier and as a valuable chemical in the process industry. READ MORE

  5. 23. Modeling of aerodynamic particle interaction

    Author : Asim Jadoon; Strömningsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : The purpose of the current study is to investigate the effect of particle-pair interaction for various separation distances and angular positions. The results obtained are used in a particle-laden turbulent jet flows in order to improve the existing Lagrangian Particle Tracking (LPT) models. READ MORE

  6. 24. Numerical study of non-spherical/spherical particles in laminar and turbulent flows

    Author : Mehdi Niazi Ardekani; Luca Brandt; Alfredo Pinelli; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : The presence of solid rigid particles alters the global transport and rheological properties of the mixture in complex (and often unpredictable) ways. In recent years a few studies have been devoted to investigating the behavior of dense suspensions in the turbulent/inertial regime with the majority of theses analyses limited to mono-disperse rigid neutrally-buoyant spheres. READ MORE

  7. 25. Adjoint-based aerodynamic shape optimization

    Author : Olivier Amoignon; Martin Berggren; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Numerical Analysis; Numerisk analys;

    Abstract : An adjoint system of the Euler equations of gas dynamics is derived in order to solve aerodynamic shape optimization problems with gradient-based methods. The derivation is based on the fully discrete flow model and involves differentiation and transposition of the system of equations obtained by an unstructured and node-centered finite-volume discretization. READ MORE