Sökning: "Method of Moments"

Visar resultat 21 - 25 av 175 avhandlingar innehållade orden Method of Moments.

  1. 21. Zero and Multi-Dimensional Modeling of Internal Combustion Engines with respect to Ion Current and Soot Formation

    Författare :Abdelhadi Ahmedi; Institutioner vid LTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; engine knock; pollutant emissions; detailed chemical kinetics; thermal ionization.; ion current sensor; method of moments; ionization; soot formation oxidation; modeling; auto-ignition; Spark ignition engine; diesel engine;

    Sammanfattning : The work presented in this thesis can be divided into the three following fields of investigation: First of all the ionization model developed in this thesis is meant to simulate the thermal ionization process or the so-called second peak. Equilibrium assumptions have been adopted for the modeling of the thermal ionization, in which Saha’s equation was derived for singly ionized molecules. LÄS MER

  3. 22. A parallel, iterative method of moments and physical optics hybrid solver for arbitrary surfaces

    Författare :Johan Edlund; Per Lötstedt; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Numerical Analysis; Numerisk analys;

    Sammanfattning : We have developed an MM–PO hybrid solver designed to deliver reasonable accuracy inexpensively in terms of both CPU-time and memory demands. The solver is based on an iterative block Gauss–Seidel process to avoid unnecessary storage and matrix computations, and can be used to solve the radiation and scattering problems for both disjunct and connected regions. LÄS MER

  4. 23. Effect of Hyporheic Exchange on Conservative and Reactive Solute Transport in Streams : Model Assessments Based on Tracer Tests

    Författare :Karin Jonsson; Anders Wörman; Bernhard H. Schmid; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; conservative; hyporheic exchange; model; reactive; retention; solute; sorption kinetics; stream transport; temporal moments; tracer experiment; Geovetenskap; Earth sciences; Geovetenskap; Sedimentology; sedimentologi;

    Sammanfattning : Understanding of the processes affecting solute transport in flowing water is important for the possibility to predict the evolution with time of polluted stream systems. This thesis presents tracer experiment methodology and model developments for solute transport in streams, with special focus on retention processes and their effect on solute stream transport. LÄS MER

  5. 24. Rapid Aerodynamic Method for Interacting Sails

    Författare :Karolina Malmek; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lifting line method; wind-assisted propulsion; sail–sail interaction; wingsail; wind propulsion system;

    Sammanfattning : Rapid performance prediction tools are required for the evaluation, optimization, and comparison of different wind propulsion systems (WPSs). These tools should capture viscous aerodynamic flow effects in 3D, especially the maximum propulsion force, stall angles and interaction effects between the lift-generating units. LÄS MER

  7. 25. Toughness of short fiber composites : an approach based on crack-bridging

    Författare :Patrik Fernberg; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Polymera konstruktionsmaterial; Polymeric Composite Materials;

    Sammanfattning : The presented work considers how to properly characterize fracture properties of short fiber composites (SFC). Associated with fracture of SFC is the creation of a comparably widespread fracture process zone. This zone develops since a number of inelastic failure mechanisms (e.g. LÄS MER