Abstract
The mean flow topology for flows with three-dimensional separation can be highly complex and the unsteady fluid dynamics are largely unexplored. Water tunnel experiments and direct numerical simulations were carried out to obtain insight into the three-dimensional separation topology for submarine-like geometries. Particle image velocimetry was employed for obtaining quantitative mean flow data. A hemisphere-cylinder model and a model of the Virginia Tech “ellipsoid” geometry were developed for investigating three-dimensional separation. At 10 degrees angle of attack, a large laminar separation bubble developed on the nose of the hemisphere-cylinder model. The bubble was shedding intermittently. When the angle of attack was increased to 30 degrees two leeward vortices were generated and the bubble shedding was reduced. The “ellipsoid” model did not exhibit a laminar nose separation bubble at angle of attack. However, for combined roll and yaw angles or, alternatively, angle-of-attack/side-slip angle combinations highly asymmetric configurations of the leeward vortices were obtained. This asymmetry may explain the static roll-instability observed in earlier experiments at Virginia Tech for mixed roll/yaw maneuvers.
| Original language | English (US) |
|---|---|
| Title of host publication | 52nd Aerospace Sciences Meeting |
| Publisher | American Institute of Aeronautics and Astronautics Inc. |
| ISBN (Print) | 9781624102561 |
| State | Published - 2014 |
| Event | 52nd Aerospace Sciences Meeting 2014 - National Harbor, United States Duration: Jan 13 2014 → Jan 17 2014 |
Other
| Other | 52nd Aerospace Sciences Meeting 2014 |
|---|---|
| Country | United States |
| City | National Harbor |
| Period | 1/13/14 → 1/17/14 |
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ASJC Scopus subject areas
- Aerospace Engineering
Cite this
Experimental investigation of flows with three-dimensional separation. / Balthazar, Michael; Gross, Andreas; Fasel, Hermann F.
52nd Aerospace Sciences Meeting. American Institute of Aeronautics and Astronautics Inc., 2014.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Experimental investigation of flows with three-dimensional separation
AU - Balthazar, Michael
AU - Gross, Andreas
AU - Fasel, Hermann F
PY - 2014
Y1 - 2014
N2 - The mean flow topology for flows with three-dimensional separation can be highly complex and the unsteady fluid dynamics are largely unexplored. Water tunnel experiments and direct numerical simulations were carried out to obtain insight into the three-dimensional separation topology for submarine-like geometries. Particle image velocimetry was employed for obtaining quantitative mean flow data. A hemisphere-cylinder model and a model of the Virginia Tech “ellipsoid” geometry were developed for investigating three-dimensional separation. At 10 degrees angle of attack, a large laminar separation bubble developed on the nose of the hemisphere-cylinder model. The bubble was shedding intermittently. When the angle of attack was increased to 30 degrees two leeward vortices were generated and the bubble shedding was reduced. The “ellipsoid” model did not exhibit a laminar nose separation bubble at angle of attack. However, for combined roll and yaw angles or, alternatively, angle-of-attack/side-slip angle combinations highly asymmetric configurations of the leeward vortices were obtained. This asymmetry may explain the static roll-instability observed in earlier experiments at Virginia Tech for mixed roll/yaw maneuvers.
AB - The mean flow topology for flows with three-dimensional separation can be highly complex and the unsteady fluid dynamics are largely unexplored. Water tunnel experiments and direct numerical simulations were carried out to obtain insight into the three-dimensional separation topology for submarine-like geometries. Particle image velocimetry was employed for obtaining quantitative mean flow data. A hemisphere-cylinder model and a model of the Virginia Tech “ellipsoid” geometry were developed for investigating three-dimensional separation. At 10 degrees angle of attack, a large laminar separation bubble developed on the nose of the hemisphere-cylinder model. The bubble was shedding intermittently. When the angle of attack was increased to 30 degrees two leeward vortices were generated and the bubble shedding was reduced. The “ellipsoid” model did not exhibit a laminar nose separation bubble at angle of attack. However, for combined roll and yaw angles or, alternatively, angle-of-attack/side-slip angle combinations highly asymmetric configurations of the leeward vortices were obtained. This asymmetry may explain the static roll-instability observed in earlier experiments at Virginia Tech for mixed roll/yaw maneuvers.
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M3 - Conference contribution
AN - SCOPUS:84938243831
SN - 9781624102561
BT - 52nd Aerospace Sciences Meeting
PB - American Institute of Aeronautics and Astronautics Inc.
ER -