Mini-spoilers for afterbody base drag reduction

D. S. Bulathsinghala, Z. Wang, I. Gursul

Research output: Contribution to conferencePaper

1 Citation (Scopus)

Abstract

Wind tunnel experiments have been carried out in order to study the effect of full-span mini-spoilers on the afterbody vortex drag of a slanted base cylinder. Two different protrusion heights (h/D = 2.5% and 5%) were examined at various chordwise locations along the upsweep. The tests were performed on a slanted base cylindrical model with an afterbody upsweep angle Φ = 28° at a test Reynolds number of 200,000 based on model diameter. Drag measurements, surface pressure measurements and 2D Particle Image Velocimetry measurements were the main experimental tools utilized within this investigation. Placing the spoilers closer to the leading edge of the upsweep caused an increased drag due to the separation induced by the spoiler itself, leading to a more diffused vortex, but with a larger circulation at the trailing-edge. Drag reductions were observed when placing the spoiler closer to the trailing-edge, with the optimum location being x′s /c = 87.5% resulting in drag reductions of 4.5% and 4.8% for h/D = 2.5% and 5% heights respectively. This reduction is due to an increase in surface pressure upstream of the spoiler. For the drag reducing spoiler location, the vortex was found to be displaced away from the surface, with the streamlines of the model trailing-edge deflected downwards into the wake of the spoiler, altering the trailing-edge flow. Unsteady aspects are discussed and underlying flow mechanisms are presented using the Proper Orthogonal Decomposition. Further results are also presented for a vortex generator configuration that was examined which may present a useful starting point for future studies. A co-rotating half delta wing type vortex generator placed at an incidence of β = 20° at x/c = 20% with a leading edge sweep of Λ = 70° was found to show the most promising results.

Conference

Conference47th AIAA Fluid Dynamics Conference, 2017
CountryUSA United States
CityDenver
Period5/06/179/06/17

Fingerprint

Drag reduction
Vortex flow
Drag
Surface measurement
Pressure measurement
Velocity measurement
Wind tunnels
Reynolds number
Decomposition
Experiments

ASJC Scopus subject areas

  • Aerospace Engineering
  • Engineering (miscellaneous)

Cite this

Bulathsinghala, D. S., Wang, Z., & Gursul, I. (2017). Mini-spoilers for afterbody base drag reduction. Paper presented at 47th AIAA Fluid Dynamics Conference, 2017, Denver, USA United States.

Mini-spoilers for afterbody base drag reduction. / Bulathsinghala, D. S.; Wang, Z.; Gursul, I.

2017. Paper presented at 47th AIAA Fluid Dynamics Conference, 2017, Denver, USA United States.

Research output: Contribution to conferencePaper

Bulathsinghala, DS, Wang, Z & Gursul, I 2017, 'Mini-spoilers for afterbody base drag reduction' Paper presented at 47th AIAA Fluid Dynamics Conference, 2017, Denver, USA United States, 5/06/17 - 9/06/17, .
Bulathsinghala DS, Wang Z, Gursul I. Mini-spoilers for afterbody base drag reduction. 2017. Paper presented at 47th AIAA Fluid Dynamics Conference, 2017, Denver, USA United States.
Bulathsinghala, D. S. ; Wang, Z. ; Gursul, I. / Mini-spoilers for afterbody base drag reduction. Paper presented at 47th AIAA Fluid Dynamics Conference, 2017, Denver, USA United States.
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