Sökning: "noise emissions"

Visar resultat 21 - 25 av 86 avhandlingar innehållade orden noise emissions.

  1. 21. Numerical Methods for Aeroacoustic Analysis of Turbomachinery

    Författare :Daniel Lindblad; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Convective Ffowcs Williams - Hawkings Equation; Computational Aeroacoustics; Acoustic Analogy; Von Neumann Stability Analysis; Tonal Noise; CAA; Harmonic Balance Method; Counter Rotating Open Rotor;

    Sammanfattning : Air transportation is today an integral part of many peoples life and it continuously grow to serve more of us in new and ingenious ways. There are however negative sides to this growth as well, such as increased noise around airports and more CO2 emissions, which must be addressed if aviation is to be part of a sustainable future. LÄS MER

  3. 22. Electric Machine Control for Energy Efficient Electric Drive Systems

    Författare :Andreas Andersson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; modulation techniques; permanent magnet synchronous machine PMSM ; Energy efficiency; inverter control.; noise assessment;

    Sammanfattning : Over the past decade, electric vehicles has increasingly become an area of attention for both academia and industry, much due to challenges such as emissions legislation and the environmental impact of the transportation sector. The absence of the broadband noise from the internal combustion engine brings new acoustic challenges for electric propulsion applications. LÄS MER

  4. 23. Gasoline Partially Premixed Combustion - An Advanced Internal Combustion Engine Concept Aimed to High Efficiency, Low Emissions and Low Acoustic Noise in the Whole Load Range

    Författare :Vittorio Manente; Förbränningsmotorer; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Environmental concerns such as global warming, the surge of crude oil prices and more stringent emission regulations are demanding the development of internal combustion engines that are highly efficient and low polluting. With classical internal combustion engine concepts such as diesel compression ignition and gasoline spark ignition engines, a trade-off exists between local and global emissions i. LÄS MER

  5. 24. Modular Battery Systems for Electric Vehicles based on Multilevel Inverter Topologies - Opportunities and Challenges

    Författare :Anton Kersten; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamic reconfiguration; Energy storage; Energy efficiency; Drive cycle efficiency; Power MOSFET; vehicles; H-bridge; Multilevel systems; Electromagnetic compatibility; Modular battery systems; Battery system performance; Modular multilevel converters; Conduction losses; Electric vehicles; Batteries; Dual battery pack; Cascaded converters; DC-AC power converters; BMS; Common mode noise; Battery modeling; vehicle electrification;

    Sammanfattning : Modular battery systems based on multilevel inverter (MLI) topologies can possibly overcome some shortcomings of two-level inverters when used for vehicle propulsion. The results presented in this thesis aim to point out the advantages and disadvantages, as well as the technical challenges, of modular vehicle battery systems based on MLIs in comparison to a conventional, two-level IGBT inverter drivetrain. LÄS MER

  7. 25. Railway Open System Tribology

    Författare :Yezhe Lyu; Ulf Olofsson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wheel; Rail; Brake; Environmental conditions; Tribology; Noise; Particle; Hjul; Räl; Broms; Miljöförhållanden; Tribologi; Ljud; Partiklar; Machine Design; Maskinkonstruktion;

    Sammanfattning : Tribology in the railway system is of increasing interest in the new railway era due to the demand for higher speed and load capacity. Since railway vehicles operate in an open environment, their performance depends greatly on temperature, humidity and natural and artificial contaminants. LÄS MER