Sökning: "Discharge coefficient"

Visar resultat 1 - 5 av 21 avhandlingar innehållade orden Discharge coefficient.

  1. 1. On Gas Dynamics of Exhaust Valves

    Författare :Marcus Winroth; P. Henrik Alfredsson; Ramis Örlü; Knud Erik Meyer; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Exhaust valve; poppet valve; dynamic valve; engine modeling; discharge coefficient; Avgasventil; rörlig ventil; motorsimulering; utsläppskoefficient; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : With increasing effects of global warming, efforts are made to make transportationin general more fuel efficient. When it comes to internal combustion engines,the most common way to improve fuel efficiency is through ‘downsizing’. Downsizingmeans that a smaller engine (with lower losses and less weight) performsthe task of a larger engine. LÄS MER

  3. 2. Numerical Studies of Flow and AssociatedLosses in the Exhaust Port of a Diesel Engine

    Författare :Yue Wang; Laszlo Fuchs; Mihai Mihaescu; Angelo Onorati; KTH; []
    Nyckelord :Internal Combustion Engine; Exhaust flow; Exhaust Valve; Exhaust Port; Large Eddy Simulation; Valve and Piston Motion; Total Pressure Losses; Energy Losses; Discharge coefficient; Flow Losses; Flow structures; Air Flow Bench; Engine-like Conditions; SRA - Energy; SRA - Energi;

    Sammanfattning : In the last decades, the focus of internal combustion engine development has moved towards more efficient and less pollutant engines. In a Diesel engine, approximately 30-40% of the energy provided by combustion is lost through the exhaust gases. The exhaust gases are hot and therefore rich of energy. LÄS MER

  4. 3. The Effective Convectivity Model for Simulation and Analysis of Melt Pool Heat Transfer in a Light Water Reactor Pressure Vessel Lower Head

    Författare :Chi Thanh Tran; Tomas Lefvert; Harri Tuomisto; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; light water reactor; hypothetical severe accident; accident progression; accident scenario; core melt pool; heat transfer; turbulent natural convection; heat transfer coefficient; phase change; mushy zone; crust; lower plenum; analytical model; effective convectivity model; CFD simulation; Thermal energy engineering; Termisk energiteknik;

    Sammanfattning : Severe accidents in a Light Water Reactor (LWR) have been a subject of intense research for the last three decades. The research in this area aims to reach understanding of the inherent physical phenomena and reduce the uncertainties in their quantification, with the ultimate goal of developing models that can be applied to safety analysis of nuclear reactors, and to evaluation of the proposed accident management schemes for mitigating the consequences of severe accidents. LÄS MER

  5. 4. Adhesion in the wheel-rail contact under contaminated conditions

    Författare :Yi Zhu; Ulf Olofsson; Ines Lopez Arteaga; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; adhesion; wheel-rail contact; contaminants; rough surfaces;

    Sammanfattning : Railway vehicles require a certain level of adhesion between wheel and rail to operate efficiently, reliably, and economically. Different levels of adhesion are needed depending on the vehicle running conditions. LÄS MER

  7. 5. Atomisation and Combustion Studies of Diesel Sprays

    Författare :Lionel Christopher Ganippa; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This thesis addresses two potential problems facing investigators involved in Diesel engine development: fuel atomisation and soot formation. A particular concern has been cavitation in nozzles and its influence on the spray and combustion, investigated through impingement studies, scaled-up transparent nozzle studies and evaluation of hydro grinding effects in a real-size nozzle. LÄS MER