Search for dissertations about: "Reduced-Order Modelling"

Showing result 1 - 5 of 12 swedish dissertations containing the words Reduced-Order Modelling.

  2. 1. Unsteady Numerical Simulations and Reduced-Order Modelling of Flows around Vehicles

    Author : Jan Östh; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Reduced-Order Modelling; Numerical Simulations; Large Eddy Simulation; Vehicle Aerodynamics;

    Abstract : In this thesis several simulations have been carried out aimed at improving the knowledge of vehicle aerodynamics and improving the flow around vehicles with respect to theaerodynamic drag. Five flows around different simplified vehicle models have been considered in five appended publications. READ MORE

  4. 2. Predicting Xenon Oscillations in PWRs using Intrusive Reduced Order Modelling

    Author : Kristoffer Pedersen; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Reduced Order Modeling; Modal Decomposition; Multi-Group Diffusion Theory; Xenon Oscillations;

    Abstract : The increasing presence of intermittent energy sources in the Swedish electricity grid necessitates a transition of Swedish nuclear reactors from constant base load operation to load-following mode. However, such changes in power can induce xenon oscillations, a phenomenon that poses operational challenges and the risk of fuel damage. READ MORE

  5. 3. Flow control and reduced-order modelling of transition in shear flows

    Author : Reza Dadfar; Dan Henningson; Vasssilis Theofilis; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Flow control; plasma actuator; wing; leading edge; flat plate; wind turbine; optimal controller; model reduction; proper orthogonal decomposition; dynamic mode decomposition.;

    Abstract : In this thesis direct numerical simulation is used to investigate the possibility to delay the transition from a laminar to a turbulent flow in boundary layer flows. Furthermore, modal analysis techniques are used to identify the coherent structures in wind turbine wake. READ MORE

  6. 4. Modelling and control of turbulent and transitional flows

    Author : Pierluigi Morra; Dan S. Henningson; Ardeshir Hanifi; André V. G. Cavalieri; Shervin Bagheri; Aimee S. Morgans; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; reduced order modeling; flow control; resolvent analysis; transi- tional boundary layer; turbulent boundary layer; drag reduction; high-fidelity wall-turbulence modelling; modellreduktion; strömningskontroll; resolvent analys; laminär- turbulent omslag; turbulent gränsskikt; motståndsminskning; väggturbulens modellering; Engineering Mechanics; Teknisk mekanik;

    Abstract : The dynamics of fluid motion can accurately be described by the Navier– Stokes equations. Manipulating these equations to reduce their complexity but preserving their main characteristics has always been a key research activity in the field of fluid mechanics. READ MORE

  7. 5. System-Wide Impacts of Distributed Generation on Power System Operation : Data-Driven Approaches to Addressing the Challenges of Integrating Distributed Generation

    Author : Tin Rabuzin; Lars Nordström; Marjan Popov; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; data-driven modelling; distributed generation; dynamic equivalencing; islanding detection; reduced order modelling; datadriven modellering; detektion av ödrift; distribuerad generation; dynamisk modellering; reducerad ordningsmodellering; Electrical Engineering; Elektro- och systemteknik;

    Abstract : Deployment of distributed generation (DG) is happening at an increasing rate driven by both the need for the reduction of humanity's carbon footprint and economic opportunities. The trend of increasing penetration levels of DG has also introduced interdependence between the responsibilities of system operators and the owners of the generating units. READ MORE