Sökning: "heat equation"

Visar resultat 1 - 5 av 156 avhandlingar innehållade orden heat equation.

  1. 1. Efficiency factors for space heating system in buildings

    Författare :Christian Brembilla; Thomas Olofsson; Ronny Östin; Mohsen Soleimani-Mohseni; Bjørn Reidar Sørensen; Umeå universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Efficiency factors of space heating; hydronic panel radiator; hydronic floor heating; multilayer wall; numerical modelling; room control volume; decrement factor; time delay; heat conduction; heat convection; heat radiation; heat storage; thermal inertia; Euler solver; Newton-Raphson method; synthetic weather file; feedback and feed-forward control strategies; adaptive control; validation methodology; uncertainty bands; robustness of model predictions; thermostatic booth simulator; differential sensitivity analysis; transient model of panel radiator with multiple storage elements; active thermal mass; benchmark performance indicator; linear regression model; calibration through uncertainty bands; hybrid model of low-energy building: law driven data driven; outdoor temperature compensation heating curve; solar radiation model; finite difference method; heat equation;

    Sammanfattning : The thesis focuses on the efficiency of the space heating system. In particular, the efficiency factors measure the efficiency of thermal zone. The efficiency factors measures how the energy is used in a space heating. LÄS MER

  2. 2. Quantum-Dot Heat Engines

    Författare :Martin Josefsson; NanoLund: Center for Nanoscience; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; quantum dot; heat engine; thermoelectric; quantum thermodynamics; quantum transport; Fysicumarkivet A:2020:Josefsson;

    Sammanfattning : This thesis explores the possibilities of using quantum dots (QDs) in nanoscale energy har- vesters converting heat into electrical energy, i.e. heat engines. From a theory perspective, these possibilities have been investigated for almost two decades, and interest in them seem to continuously increase over time. LÄS MER

  3. 3. Clothing Evaporative Resistance: Its Measurements and Application in Prediction of Heat Strain

    Författare :Faming Wang; Ergonomi och aerosolteknologi; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; thermal manikin; clothing ensemble; evaporative resistance; localised evaporative resistance; thermophysiological response; heat stress; heat strain; the Predicted Heat Strain PHS model;

    Sammanfattning : Clothing evaporative resistance is one of the most important inputs for both the modelling and for standards dealing with thermal comfort and heat stress. It might be determined on guarded hotplates, on sweating manikins or even on human subjects. LÄS MER

  4. 4. A weak space-time formulation for the linear stochastic heat equation

    Författare :Matteo Molteni; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Inf-sup theory; Stochastic heat equation; Petrov-Galerkin; Finite element; Crank-Nicolson; Quasi-optimality;

    Sammanfattning : The topic covered in this thesis is the introduction of a new formulation for the linear stochastic heat equation driven by additive noise, based on the space-time variational formulation for its deterministic counterpart. Having a variational formulation allows the use of the so called inf-sup theory in order to obtain results of existence and uniqueness in a relatively simple way. LÄS MER

  5. 5. Heat and Mass Transfer in Built Structures - Numerical Analyses

    Författare :Jinkai Wang; Chalmers University of Technology; []
    Nyckelord :air convection; heat; numerical procedure; air and moisture transport; long-term thermal performance; numerical stability; gas-filled foam; thermal aging; simulation;

    Sammanfattning : Heat and mass transport processes are often present simultaneously in built structures in building applications. The emphasis of this thesis is to contribute to knowledge about predicting the effects of combined heat and mass transport in built structures. LÄS MER