Sökning: "transient techniques"

Visar resultat 1 - 5 av 187 avhandlingar innehållade orden transient techniques.

  1. 1. Transient elastohydrodynamic lubrication : Effects of geometry, surface roughness, temperature, and plastic deformation

    Författare :Tobias Hultqvist; Roland Larsson; Pär Marklund; Wassim Habchi; Luleå tekniska universitet; []

    Sammanfattning : The urgent need to reduce greenhouse gas emissions in combination with an increased use of sustainable energy resources have led to immense efforts on improving energy efficiency of mechanical systems. Consequently, modern machine elements are typically lubricated with low viscosity oils and designed to endure an increasingly high power density. LÄS MER

  2. 2. Electrochemical characterisation of porous cathodes in the polymer electrolyte fuel cell

    Författare :Frédéric Jaouen; KTH; []
    Nyckelord :polymer electrolyte fuel cell; cathode; mass transport; porous electrode; modelling; agglomerate model; electrochemical impedance spectroscopy; current interrupt; transient techniques; non-noble catalysts;

    Sammanfattning : Polymer electrolyte fuel cells (PEFC) convert chemicalenergy into electrical energy with higher efficiency thaninternal combustion engines. They are particularly suited fortransportation applications or portable devices owing to theirhigh power density and low operating temperature. LÄS MER

  3. 3. Modeling Complex Engines as Dynamic Powertrain Members

    Författare :Sixten Berglund; Chalmers University of Technology; []
    Nyckelord :vehicle; diesel engine; simulation; supercharging; drivability; toolbox; fuel economy; transient; modeling; turbocharging; control system; powertrain; emissions; performance; dynamic; system;

    Sammanfattning : Engine modeling and simulation have been necessary tools for efficient product development in the automotive industry for some time. The scope of this work is novel engine models, tools, and methods for powertrain research and development. LÄS MER

  4. 4. Experimental and Numerical Investigation of the Quenching Process on Rotary Hollow Cylinder by Multiple Impinging Jets

    Författare :Mohammad Jahedi; Bahram Moshfegh; Fredrik Berntsson; Joakim Wren; Rahmatollah Khodabandeh; Högskolan i Gävle; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multiple jet arrays; Transient boiling; Moving surface; Rotating surface; Inverse heat conduction problem; Quenching; Water impinging jet; Experimental study; Matriser av jetstrålar; Direktverkande jetstrålar; Transient kokning; Roterande yta; Icke-stationär invers värmeledning; Släckning; Experimentell studie; Intelligent industri; Intelligent Industry;

    Sammanfattning : The worldwide competitive market on metal products with higher quality in industry has increased the need to implement more advanced and controllable quenching techniques in the hardening stage of the heat treatment process. Moreover, sustainability and energy efficiency are key factors to consider in the development of advanced quenching techniques. LÄS MER

  5. 5. Simplified models for emission formation in diesel engines during transient operation

    Författare :Anders Westlund; Hans-Erik Ångström; Martti Larmi; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Diesel engine; emission modeling; transient operation; NOx; Soot; Mechanical energy engineering; Mekanisk energiteknik;

    Sammanfattning : The work presented in this thesis is the result of the KTH CICERO project “Dynamic Engine Performance” in which the main objective was to develop simple models foremission formation. The demand for such models is increasing, mainly due to the tightening emission legislation for diesel engines which has lead to more complex engines and thereby more laborious development and calibration processes. LÄS MER