ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • 2005-2009  (3)
Sammlung
Erscheinungszeitraum
Jahr
  • 1
    Publikationsdatum: 2005-06-23
    Beschreibung: The aerodynamic performance of the National Renewable Energy Laboratory (NREL) Phase VI horizontal axis wind turbine (HAWT) under yawed flow conditions is studied using a three-dimensional unsteady viscous flow analysis. Simulations have been performed for upwind cases at several wind speeds and yaw angles. Results presented include radial distribution of the normal and tangential forces, shaft torque, root flap moment, and surface pressure distributions at selected radial locations. The results are compared with the experimental data for the NREL Phase VI rotor. At low wind speeds (∼7m∕s) where the flow is fully attached, even an algebraic turbulence model based simulation gives good agreement with measurements. When the flow is massively separated (wind speed of 20m∕s or above), many of the computed quantities become insensitive to turbulence and transition model effects, and the calculations show overall agreement with experiments. When the flow is partially separated at wind speed above 15m∕s, encouraging results were obtained with a combination of the Spalart-Allmaras turbulence model and Eppler’s transition model only at high enough wind speeds.
    Print ISSN: 0199-6231
    Digitale ISSN: 1528-8986
    Thema: Energietechnik
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Publikationsdatum: 2006-07-16
    Beschreibung: The aerodynamic performance of a wind turbine rotor equipped with circulation enhancement technology (trailing-edge blowing or Gurney flaps) is investigated using a three-dimensional unsteady viscous flow analysis. The National Renewable Energy Laboratory Phase VI horizontal axis wind turbine is chosen as the baseline configuration. Experimental data for the baseline case is used to validate the flow solver, prior to its use in exploring these concepts. Calculations have been performed for axial and yawed flow at several wind conditions. Results presented include radial distribution of the normal and tangential forces, shaft torque, root flap moment, and surface pressure distributions at selected radial locations. At low wind speed (7m∕s) where the flow is fully attached, it is shown that a Coanda jet at the trailing edge of the rotor blade is effective at increasing circulation resulting in an increase of lift and the chordwise thrust force. This leads to an increased amount of net power generation compared to the baseline configuration for moderate blowing coefficients (Cμ⩽0.075). A passive Gurney flap was found to increase the bound circulation and produce increased power in a manner similar to Coanda jet. At high wind speed (15m∕s) where the flow is separated, both the Coanda jet and Gurney flap become ineffective. The effects of these two concepts on the root bending moments have also been studied.
    Print ISSN: 0199-6231
    Digitale ISSN: 1528-8986
    Thema: Energietechnik
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Publikationsdatum: 2019-07-11
    Beschreibung: Circulation Control technology is a very effective way of achieving high lift forces required by aircraft during take-off and landing. This technology can also directly control the flow field over the wing. Compared to a conventional high-lift system, a Circulation Control Wing (CCW) can generate comparable or higher lift forces during take-off/landing with fewer or no moving parts and much less complexity. In this work, an unsteady three-dimensional Navier-Stokes analysis procedure has been developed and applied to Circulation Control Wing configurations. The effects of 2-D steady jets and 2-D pulsed jets on the aerodynamic performance of CCW airfoils have been investigated. It is found that a steady jet can generate very high lift at zero angle of attack without stall, and that a small amount of blowing can eliminate vortex shedding at the trailing edge, a potential noise source. It is also found that a pulsed jet can achieve the same high lift as a steady jet at lower mass flow rates, especially at a high frequency, and that the Strouhal number has a more dominant effect on the pulsed jet performance than just the frequency or the free-stream velocity.
    Schlagwort(e): Fluid Mechanics and Thermodynamics
    Materialart: Proceedings of the 2004 NASA/ONR Circulation Control Workshop, Part 1; 295-321; NASA/CP-2005-213509/PT1
    Format: application/pdf
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...