Pressure measurements and flow field visualization ob a delta wing with periodic blowing and suction

Yair Guy, Julie A. Morrow, Thomas E. McLaughlin, Israel J Wygnanski

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Scopus citations

Abstract

A promising technique to delay. Vortex breakdown over a 70°-sweep delta wing is experimentally investigated in "a water tunnel and in a low-speed wind tunnel at the USAF Academy. Periodic blowing and suction with zero net mass flux is applied at the leading edge of the wing. The: location of the. vortex breakdown is visualized in. the' water tunnel at a. freestream velocity of 0.122 m/s, corresponding to a chord Reynolds number of 033 ×105. The pressure distribution over the upper surface of the wing is measured in the wind tunnel at freestream velocity of 4.3 m/s, corresponding to chord Reynolds number of 2.1×105. A parametric.study is first conducted in the water tunnel at.angles of attack -from. 20° to 46°, to establish the effect of the frequency of the periodic flow excitation on the vortex breakdown location. The effect of four frequencies is. investigated, 0.42, 0.6, 0.83- and 1.25 Hz. It is found that the effect of the periodic flow, excitation varies - with the frequency. It is maximized at an excitation frequency of 0.6 Hz, corresponding to a nondimensional frequency of 1.5. At this frequency the vortex, breakdown, location is delayed by up to 0.2 chordlengfhs. Pressure distribution on the 'upper surface of.the wing is measured in the low speed wind tunnel, at angles, of attack of 20° to 40°. The flow excitation frequency in these tests is 10 Hz, corresponding to a nondimensional frequency of 1.7. The momentum coefficient is 0.004. It is found that the flow excitation delays wing, stall from an angle of attack of 28° approximately to 40° approximately -and greatly increases the normal force at high angles of attack. A maximum increase of 38% in the normal force is obtained at an angle of attack of 40°, relative to the unforced case. Based on the results obtained in this investigation, it is concluded that periodic, blowing and suction, applied at the leading edge of a delta wing, delays vortex breakdown, delays stall and greatly increases normal force: at high angles of attack. The operational range of the wing can be thus extended to higher angles of attack.

Original languageEnglish (US)
Title of host publication24th Atmospheric Flight Mechanics Conference
PublisherAmerican Institute of Aeronautics and Astronautics Inc, AIAA
ISBN (Print)9780000000002
StatePublished - 1999
Event24th Atmospheric Flight Mechanics Conference, 1999 - Portland, United States
Duration: Aug 9 1999Aug 11 1999

Other

Other24th Atmospheric Flight Mechanics Conference, 1999
CountryUnited States
CityPortland
Period8/9/998/11/99

ASJC Scopus subject areas

  • Aerospace Engineering
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Pressure measurements and flow field visualization ob a delta wing with periodic blowing and suction'. Together they form a unique fingerprint.

  • Cite this

    Guy, Y., Morrow, J. A., McLaughlin, T. E., & Wygnanski, I. J. (1999). Pressure measurements and flow field visualization ob a delta wing with periodic blowing and suction. In 24th Atmospheric Flight Mechanics Conference American Institute of Aeronautics and Astronautics Inc, AIAA.