Sökning: "steady state"

Visar resultat 11 - 15 av 706 avhandlingar innehållade orden steady state.

1. 11. Synchrophasor based Steady State Model Synthesis of Active Distribution Networks

   Författare :Farhan Mahmood; Luigi Vanfretti; Francisco Gonzalez-Longatt; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Active distribution networks; phasor measurement units; model synthesis; real-time simulation; hardware-in-the-loop.; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : With the increased penetration of distributed energy resources (DERs) at lower voltage levels, distribution networks (DNs) are being transformed into active grids. This has led to a paradigm shift in the operation, planning and control of DNs. LÄS MER

3. 12. Realistic simulations of delta wing aerodynamics using novel CFD methods

   Författare :Stefan Görtz; Arthur Rizzi; Miguel Visbal; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space and plasma physics; CFD; aerodynamics; flow physics; steady; unsteady; delta wing; vortical flow; Rymd- och plasmafysik; Space physics; Rymdfysik;

   Sammanfattning : The overall goal of the research presented in this thesis is to extend the physical understanding of the unsteady external aerodynamics associated with highly maneuverable delta-wing aircraft by using and developing novel, more efficient computational fluid dynamics (CFD) tools. More specific, the main purpose is to simulate and better understand the basic fluid phenomena, such as vortex breakdown, that limit the performance of delta-wing aircraft. LÄS MER

4. 13. FLOW FIELD IN A HIGH HEAD FRANCIS TURBINE DRAFT TUBE DURING TRANSIENT OPERATIONS

   Författare :Rahul Goyal; Michel J. Cervantes; Bhupendra K. Gandhi; Gabriel Ciocan; Lisa Prahl; Ramis Orlu; Gunilla Andree; Andrea Toffolo; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Francis turbine; Steady state; Transient; Particle Image Velocimetry; Vortex Rope; Strömningslära; Fluid Mechanics;

   Sammanfattning : Hydroelectricity plays an important role to balance the stability of grid network.  In order to improve the stability of presently high loaded grids, hydropower plants are being operated over a wide range of operations and experiencing frequent start-stop, load rejection, and load acceptance. LÄS MER

5. 14. Firm dynamics and competition in the electricity market

   Författare :Aili Tang; Lars Hultkrantz; Magnus Lodefalk; Niklas Jakobsson; Robert Lundmark; Örebro universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Firm growth; profitability; steady-state; market power; competition; Boone indicator;

   Sammanfattning : This thesis consists of four independent essays that deal with the firm dynamics and competition in the electricity market. Specifically, it addresses two important facets of firm dynamics, namely, firm performance (growth and profitability) and the change in competition intensity that Swedish electricity firms face, brought by the process of deregulation in Swedish electricity market. LÄS MER

7. 15. Simplifying complex models : Application of modeling tools in exposure assessment of organic pollutants

   Författare :Emma Undeman; Michael McLachlan; Kathrin Fenner; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mass balance model; environmental modeling; exposure modeling; bioaccumulation; organic contaminants; emission estimate; plant model; steady state; poly parameter linear free energy relationship; PPLFER; ecosystem susceptibility; Environmental chemistry; Miljökemi; Persistent organic compounds; Persistenta organiska föreningar; Applied Environmental Science; tillämpad miljövetenskap;

   Sammanfattning : Thousands of chemicals are used in society, but the exposure to humans and other organisms has been measured only for a small number of compounds. Modeling tools constitute low-cost and effective alternatives to measurements for the assessment of exposure. LÄS MER