Sökning: "non-uniform channel"

Visar resultat 1 - 5 av 13 avhandlingar innehållade orden non-uniform channel.

  1. 1. Modeling and Simulations of Multiphysics Phenomena ad Performance in Proton Exchange Membrane Fuel Cells

    Författare :Shian Li; Värmeöverföring; []
    Nyckelord :PEMFC; agglomerate model; interdigitated flow field; GDL deformation; flow field design; metal foam; cooling plate; non-uniform channel; wavy channel; modeling and simulation.;

    Sammanfattning : Proton exchange membrane fuel cells (PEMFCs) are considered as the mostpromising alternative power sources with a wide variety of applications owing to their attractive advantages compared to other conventional power sources. During the past decades, the cell performance has been gradually improved. LÄS MER

  3. 2. Flow Maldistribution in Exhaust Aftertreatment Systems - Numerical Simulations

    Författare :Pratheeba Chanda Nagarajan; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Catalyst; Flow maldistribution; Transient; CFD Simulations; Reactive flows; Uniformity Index; Exhaust AfterTreatment Systems;

    Sammanfattning : To comply with the stringent emission norms under every driving condition, including the coldstart conditions and Real Driving Emissions (RDE) tests, accurate models that capture the spatial and temporal variation of flow distribution information in Exhaust AfterTreatment Systems (EATS) are required. This study is aimed at characterizing and quantifying flow distribution in EATS under transient conditions with realistic geometry that illustrates the complex nature of the flow conditions. LÄS MER

  4. 3. Mathematical Analysis of Forced Convective Flow Due to Stretching Sheet and Instabilities of Natural Convective Flow

    Författare :Prashant G Metri; Sergei Silvestrov; Rebei Bel-Fdhila; Mälardalens högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Boundary layer theory; Heat and Mass transfer; Partial differential equations; Stretching sheet; Mathematics Applied Mathematics; matematik tillämpad matematik;

    Sammanfattning : The investigations presented in the thesis are theoretical studies of magnetohydrodynamic flows, heat and mass transfer in Newtonian/non-Newtonian cooling liquids, due to horizontal/vertical stretching sheet. The theoretical studies include the effect of magnetic field, uniform and non-uniform heat source/sink (flow and temperature dependent heat source/sink) effects. LÄS MER

  5. 4. Coarse Graining Monte Carlo Methods for Wireless Channels and Stochastic Differential Equations

    Författare :Håkon Hoel; Anders Szepessy; Ola Hössjer; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Coarse graining; Monte Carlo Methods; Stochastic processes; Numerical analysis; Numerisk analys;

    Sammanfattning : This thesis consists of two papers considering different aspects of stochastic process modelling and the minimisation of computational cost. In the first paper, we analyse statistical signal properties and develop a Gaussian pro- cess model for scenarios with a moving receiver in a scattering environment, as in Clarke’s model, with the generalisation that noise is introduced through scatterers randomly flip- ping on and off as a function of time. LÄS MER

  7. 5. User Effect Mitigation in MIMO Terminal Antennas

    Författare :Ivaylo Vasilev; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : The rapid growth of cellular technology over the past decade transformed our lives, enabling billions of people to enjoy interactive multimedia content and ubiquitous connectivity through a device that can fit into the palm of a hand. In part the explosive growth of the smartphone market is enabled by innovative antenna system technologies, such as multiple-input multiple-output (MIMO) systems, facilitating high data rates and reliable connections. LÄS MER