Sökning: "discrete ordinates method"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden discrete ordinates method.

  1. 1. A neutron noise solver based on a discrete ordinates method

    Författare :Huaiqian Yi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; diffusion synthetic acceleration; nuclear reactor modelling; deterministic neutron transport methods; neutron noise; convergence analysis; discrete ordinates;

    Sammanfattning : A neutron noise transport modelling tool is presented in this thesis. The simulator allows to determine the static solution of a critical system and the neutron noise induced by a prescribed perturbation of the critical system. The simulator is based on the neutron balance equations in the frequency domain and for two-dimensional systems. LÄS MER

  3. 2. Investigation of a discrete ordinates method for neutron noise simulations in the frequency domain

    Författare :Huaiqian Yi; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Deterministic neutron transport; Neutron noise; Ray effects; Numerical acceleration; Discrete ordinates method;

    Sammanfattning : During normal operations of a nuclear reactor, neutron flux measurements show small fluctuations around mean values, the so-called neutron noise. These fluctuations may be driven by a variety of perturbations, e.g., mechanical vibrations of core components. LÄS MER

  4. 3. Testing for Periodicity and Trend in Long-Memory Processes

    Författare :Abdullah Almasri; Statistiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Statistics; temperature data.; sunspots data; wind speed data; varve data; Siegel’s test; Fisher’s test; periodogram; Fractional difference process; Discrete wavelet transform; operations research; programming; actuarial mathematics; Statistik; operationsanalys; programmering; aktuariematematik; Wavelets; Statistik;

    Sammanfattning : This thesis presents methods of testing the periodicity and trend for the time series, which exhibit dependence over long periods of time. Many such processes can be modeled by a class of models called fractionally differenced processes. LÄS MER

  5. 4. On Radiative Heat Transfer Modeling with Relevance for Combustor and Biomass Furnaces

    Författare :Mehdi Bahador; Värmeöverföring; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; termodynamik; fluiddynamik; plasma; Thermal engineering; applied thermodynamics; Termisk teknik; plasmas; Gaser; Thermal Radiation; Scattering; Heat load; Gases; fluid dynamics; Biomass Furnaces; framdrivningssystem; Motorer; Motors and propulsion systems;

    Sammanfattning : Thermal radiation sometimes is the dominating heat transfer mode in combustion chambers and furnaces and therefore in the design of many relevant industrial facilities prediction of it is necessary. During previous years many research efforts in the radiative heat transfer field have originated and many methods and models from simple to complex have been developed. LÄS MER

  7. 5. Experimental and numerical studies of thermal radiation in gas, coal and co-fired pilot test facilities

    Författare :Adrian Gunnarsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rotary kiln; soot volume fraction; Radiative heat transfer; co-firing;

    Sammanfattning : Throughout the industrialized era, fossil fuels have been used extensively in combustion processes to generate heat and electricity. However, the combustion of such fuels creates emissions of greenhouse gases, mainly carbon dioxide, and other hazardous products. LÄS MER