Sökning: "Cut-off frequency"

Visar resultat 1 - 5 av 58 avhandlingar innehållade orden Cut-off frequency.

  1. 1. Control and Optimization of Fuel Cell Based Powertrain for Automotive Applications

    Författare :Qian Xun; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power distribution; Cut-off frequency; Fuel cell; Chance-constraint co-design optimization; Supercapacitors; Convex programming; Electric vehicles; Load disturbance compensator; DC-link voltage; Robust co-design optimization; Batteries;

    Sammanfattning : Fuel cell powered electric vehicles, with fast-refueling time, high energy density, and zero CO2 emissions, are becoming a promising solution for future fossil-free transportation. However, the relatively slow dynamic response and the inability of recovering the regenerative energy make vehicles solely powered by fuel cells not an immediately attractive solution. LÄS MER

  3. 2. Contribution to Numerical and Experimental Studies of Flutter in Space Turbines. Aerodynamic Analysis of Subsonic or Supersonic Flows in Response to a Prescribed Vibratory Mode of the Structure

    Författare :Hakim Ferria; Pascal Ferrand; Torsten Fransson; François Moyroud; France Ecole Centrale de Lyon Laboratoire de Mécanique des Fluides et d'Acoustique; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flutter; space turbine; LRANS computation; flutter measurement; shock wave boundary layer interaction; blisk; cut-on cut-off condition; interblade phase angle; combined modes;

    Sammanfattning : Modern turbomachines are designed towards thinner, lighter and highly loaded blades. This gives rise to increased sensitivity to flow induced vibrations such as flutter, which leads to structure failure in a short period of time if not sufficiently damped. LÄS MER

  4. 3. InAs/AlSb HEMTs for Cryogenic Low-Noise Applications

    Författare :Giuseppe Moschetti; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cryogenic; metamorphic; high frequency; high electron mobility transistor HEMT ; low power; low noise.; InAs AlSb;

    Sammanfattning : The InAs/AlSb high electron mobility transistor (HEMT) is an emerging microwave device technology. The high electron mobility and high peak electron velocity of the InAs channel makes this device technology a potential candidate for low-noise applications operating at very low power dissipation. LÄS MER

  5. 4. Ultra-Low Power InAs/AlSb HEMTs for Cryogenic Low-Noise Applications

    Författare :Giuseppe Moschetti; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; low noise; InAs AlSb; metamorphic; low power; high frequency; high electron mobility transistor HEMT ; cryogenic; ion implantation;

    Sammanfattning : The InAs/AlSb high electron mobility transistor (HEMT) is an emerging microwave device technology for ultra-low power and low noise applications. Due to the low bandgap (0. LÄS MER

  7. 5. The Radio Frequency Single-Electron Transistor and the Horizon Picture for Tunneling

    Författare :Peter Wahlgren; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The main part of this thesis concerns the development of a new type of single electron transistor (SET) called the radio frequency single electron transistor (RF-SET). The RF-SET is the most sensitive electrometer demonstrated. LÄS MER