Sökning: "discretized calculations"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden discretized calculations.

  1. 1. Estimation of Thermal and Hydraulic Characteristics of Compact Brazed Plate Heat Exchangers

    Författare :Vijaya Sekhar Gullapalli; Institutionen för energivetenskaper; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Brazed plate heat exchangers; CFD; heat transfer; pressure drop; heat exchanger selection software; transcritical-CO2 calculations; heat exchanger rating; evaporation; condensation; refrigerant properties; discretized calculations;

    Sammanfattning : This thesis work presents various performance estimation methods of compact brazed plate heat exchangers (BPHE) operating in single phase, condenser, evaporator, cascaded and transcritical applications. Such methods play a vital role in development of heat exchanger selection software and during geometry parameter estimation in the new product development process. LÄS MER

  3. 2. On Methods for Discrete Topology Optimization of Continuum Structures

    Författare :Mats Werme; Krister Svanberg; Wolfgang Achtziger; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Topology optimization; Stress constraints; Sensitivity calculations; Neighbourhood search methods; Sequential integer programming; Optimization; systems theory; Optimeringslära; systemteori;

    Sammanfattning : This thesis consists of an introduction and seven appended papers. The purpose of the introduction is to give an overview of the field of topology optimization of discretized load carrying continuum structures. LÄS MER

  4. 3. Uncertainty and sensitivity analysis applied to LWR neutronic and thermal-hydraulic calculations

    Författare :Augusto Hernandéz Solís; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sensitivity analysis; Nuclear best estimate codes; uncertainty analysis;

    Sammanfattning : The deterministic modeling of LWRs begins with the computation of energy‐collapsed and homogenizedmacroscopic cross‐sections by means of a lattice code. Once these parameters are functionalized as a functionof the reactor state variables and discretized in space, they are used as input variables by core simulators inorder to calculate the spatial distribution of the neutron flux and thus, the spatial distribution of the power. LÄS MER

  5. 4. Periodized Thermal Greens Functions and Applications

    Författare :Andro Sabashvili; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; condensed matter physics; Greens function; graphene; DMFT; RPA; GW;

    Sammanfattning : This work describes a new formalism for Fermionic thermal Greens functions that are discretized in imaginary time. The discretization makes the thermal Greens function periodic in imaginary (Matsubara) frequency space and requires a generalisation of the Dyson equation and Luttinger-Ward-Baym-Kadanoff functional. LÄS MER

  7. 5. Absorbing boundary techniques for the time-dependent Schrödinger equation

    Författare :Anna Nissen; Gunilla Kreiss; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : Chemical dissociation processes are important in quantum dynamics. Such processes can be investigated theoretically and numerically through the time-dependent Schrödinger equation, which gives a quantum mechanical description of molecular dynamics.This thesis discusses the numerical simulation of chemical reactions involving dissociation. LÄS MER