Experimental investigation of flows with three-dimensional separation

Michael Balthazar, Andreas Gross, Hermann F. Fasel

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


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 languageEnglish (US)
Title of host publication52nd Aerospace Sciences Meeting
PublisherAmerican Institute of Aeronautics and Astronautics Inc.
ISBN (Electronic)9781624102561
StatePublished - 2014
Event52nd Aerospace Sciences Meeting 2014 - National Harbor, United States
Duration: Jan 13 2014Jan 17 2014

Publication series

Name52nd Aerospace Sciences Meeting


Other52nd Aerospace Sciences Meeting 2014
Country/TerritoryUnited States
CityNational Harbor

ASJC Scopus subject areas

  • Aerospace Engineering


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