rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: In-flight receptivity experiments on a 30-degree swept-wing using micron-sized discrete roughness elements
  name:
    name part: Carpenter, Andrew L.
    role:
      role term: creator
  name:
    name part: Saric, W. S.
    role:
      role term: thesis advisor.
  type of resource: text
  genre: bibliography
  origin info:
    place:
      place term: txu
    date issued: 2010
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: electronic
    form: remote
    extent: 1 online resource.
  abstract: One of the last remaining challenges preventing the laminarization of sweptwings is the control of unstable crossflow vortices. In low-disturbance environments the transition from laminar to turbulent flow on the swept-wing initially takes the path of receptivity, where surface roughness or disturbances in the environment introduce shortwavelength disturbances into the boundary layer. This is followed by development and linear growth of stationary crossflow vortices that modify the mean flow, changing the stability characteristics of the boundary layer. Finally, breakdown to turbulence occurs over a short length scale due to the high-frequency secondary instability. The receptivity mechanism is the least understood, yet holds the most promise for providing a laminar flow control strategy. Results of a 3-year flight test program focused on receptivity measurements and laminar flow control on a 30-degree swept-wing are presented. A swept-wing test article was mounted on the port wing of a Cessna O-2A aircraft and operated at a chord Reynolds number of 6.5 to 7.5 million. Spanwise-periodic, micronsized discrete roughness elements were applied at the leading edge of the swept-wing in order to excite the most unstable crossflow wavelength and promote early boundary layer transition. An infrared camera was used to detect boundary-layer transition due to changes in leading-edge roughness. Combined with the IR camera, a new technique of calibrating surface-mounted hotfilms was developed for making disturbance-amplitude measurements downstream of modulated roughness heights. This technique proved to be effective at measuring disturbance amplitudes and can be applied in future tests where instrumentation is limited. Furthermore, laminar flow control was performed with subcritically-spaced roughness. A 100% increase in the region of laminar flow was achieved for some of the conditions tested here.
  note: by Andrew L. Carpenter.
  note: "Major Subject: Aerospace Engineering"
  note: Title from author supplied metadata (automated record created 2010-03-12 12:08:51).
  note: Electronic resource.
  note: Doctor of Philosophy Texas A&M University 2009 http://hdl.handle.net/1969.1/ETD-TAMU-2009-05-728
  note: Includes bibliographical references.
  note: Text (Dissertation)
  subject:
    topic: Major Aerospace Engineering
  subject:
    topic: Infrared Thermography
  subject:
    topic: Roughness
  subject:
    topic: Laminar Flow
  subject:
    topic: Swept-Wing
  subject:
    topic: Receptivity
  subject:
    topic: Flight Test
  subject:
    topic: Boundary Layer
  subject:
    topic: Hotfilms
  identifier: http://hdl.handle.net/1969.1/ETD-TAMU-2009-05-728
  record info:
    record content source: TXA
    record creation date: 100428
    record change date: 20151201150128.0
    record identifier: in00002574587