Sökning: "numerical model"

Visar resultat 21 - 25 av 1991 avhandlingar innehållade orden numerical model.

  1. 21. Numerical Investigations of Turbulent Flow in Water Turbines

    Författare :Håkan Nilsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multiblock; Parallel; Visualization; Validation; Verification; Turbine; CFD; Francis; Numerical; Kaplan;

    Sammanfattning : This thesis investigates turbulent flow in water turbines, focusing onthe flow in the vicinity of reaction water turbine runners such as theKaplan runner and the Francis runner. The method of investigationis principally numerical although some experimental observations andmeasurements made in the present work and elsewhere are included. LÄS MER

  3. 22. Efficiency factors for space heating system in buildings

    Författare :Christian Brembilla; Thomas Olofsson; Ronny Östin; Mohsen Soleimani-Mohseni; Bjørn Reidar Sørensen; Umeå universitet; []
    Nyckelord :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

  4. 23. Numerical modelling of geomaterials at failure

    Författare :Alex Spetz; Byggnadsmekanik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; soil-structure interaction; soil plasticity; phase-field fracture model; compression driven fractures; artificial rock; porous rock; finite element analysis; isogeometric analysis; NURBS; numerical methods;

    Sammanfattning : Geotechnical engineering is the science dealing with mechanics of soils and rocks and its engineering applications. Geotechnical engineering projects vary in a wide range, from evaluation of the stability of natural slopes and man-made soil deposits, to the design of earthworks and foundations. LÄS MER

  5. 24. Terrain Modelling with GIS for Tectonic Geomorphology : Numerical Methods and Applications

    Författare :Gyözö Jordan; Ulf Qvarfort; Tsehaie Woldai; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Environmental technology; digital elevation model; digital terrain modelling; GIS; morphometry; tectonic geomorphology; Miljöteknik; Environmental engineering; Miljöteknik;

    Sammanfattning : Analysis of digital elevation models (DEMs) by means of geomorphometry provides means of recognising fractures and characterising the morphotectonics of an area in a quantitative way. The objective of the thesis is to develop numerical methods and a consistent GIS methodology for tectonic geomorphology and apply it to test sites. LÄS MER

  7. 25. Model Order Reduction Based on Semidefinite Programming

    Författare :Aivar Sootla; Institutionen för reglerteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; model reduction; parameterized model reduction; nu-gap metric; semidefinite programming; frequency response matching.;

    Sammanfattning : The main topic of this PhD thesis is complexity reduction of linear time-invariant models. The complexity in such systems is measured by the number of differential equations forming the dynamical system. This number is called the order of the system. LÄS MER