Sökning: "Gas porosity"

Visar resultat 1 - 5 av 65 avhandlingar innehållade orden Gas porosity.

  1. 1. Factors Related to the Formation of Gas Porosity in Grey Cast Iron: Investigation of Core Gas Evolution and Gas Concentrations in Molten Iron

    Författare :Jessica Orlenius; [2008]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; core binders; Gas porosity; hydrogen; grey iron; gas absorption; nitrogen; oxygen; gas evolution rate; green sand; mould filling; gas volume; gas solubility;

    Sammanfattning : Since gas porosity is a major casting problem, it is of greatest importance to increase the knowledge about the foundry process in order to minimise the presence of gas porosity and thereby improving the casting quality. Gas porosity is generally considered to originate from gases precipitated during solidification of iron and from entrained gas picked up by the metal during the mould filling. LÄS MER

  2. 2. On Diffusion Transport Properties in Fuel Cell Gas Diffusion Layers Using the Lattice Boltzmann Method

    Detta är en avhandling från Department of Energy Sciences, Lund University

    Författare :Mayken Espinoza Andaluz; [2017]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; PEFC; lattice Boltzmann method; gas diffusion layers; porosity; Gas-phase tortuosity; permeability; inertial coefficient; diffusibility; pore-scale modeling;

    Sammanfattning : The polymer electrolyte fuel cell (PEFC) is considered as one of the most promising devices for providing efficient, clean and noiseless conversion of chemical energy to electrical energy. This device can provide electrical and thermal energy for transport, mobile and stationary applications ranging in a wide range of power requirements. LÄS MER

  3. 3. On Microstructural Analysis of Porous Media Existing in Fuel Cells Using the Lattice Boltzmann Method

    Detta är en avhandling från Department of Energy Sciences, Lund University

    Författare :Mayken Espinoza Andaluz; [2015]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Porous media; lattice Boltzmann method; microscale; Gas-phase tortuosity; Porosity; Fuel Cell;

    Sammanfattning : This Licentiate thesis aims to gain understanding related to the fluid behavior in porous media existent in fuel cells (FCs) at microscale. In order to achieve this; the widely used methodology for solving problems in porous media has been applied, the Lattice Boltzmann Method (LBM). LÄS MER

  4. 4. Analysis of Deformation of Gas Diffusion Layers and the Impact on Performance of PEM Fuel Cells

    Detta är en avhandling från Department of Energy Sciences, Lund University

    Författare :Jiatang Wang; [2017-07]
    Nyckelord :PEM fuel cell; compression ratio; assembly pressure; porosity; deformed GDL; electric resistance; transport phenomena; model; performance; analysis; OpenFOAM;

    Sammanfattning : Proton exchange membrane (PEM) fuel cells have been promoted due to significant breakthroughs in various aspects and increasing public interests. The porous features of the gas diffusion layer (GDL) and the necessary assembly processes generate localized pressure forces on the channel/shoulder structure of the bi-polar plates (BPP). LÄS MER

  5. 5. Open porosity fission gas release model applied to nuclear fuels

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Antoine Claisse; Pär Olsson; Arndt Schubert; [2015]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Nitride fuels have gained a new interest in the last few years as both a candidate for GEN IV reactors and as accident tolerant fuels for current light water reactors. They however are decades behind oxide fuels when it comes to qualication and development of tools to assess their performances. In this thesis, such a tool is developed. LÄS MER