The forces and pressures on a generic bluff body in ground effect were investigated. The bluff-body model was equipped with interchangeable underbody diffuser ramps and side plates. Five different diffuser angles were tested: 5, 10, 15, 17, and 20 deg to the horizontal. The experiments were undertaken in a low-speed wind tunnel equipped with a moving ground. Load cells, pressure taps, and surface flow visualization were the techniques used to evaluate the flow field. The flow field is characterized by vortex flow and three-dimensional flow separation. A region of hysteresis was found for the 15, 17, and 20 deg diffusers. As the ride height is varied, five different flow types can be identified with three subtypes within the region of hysteresis. The force reduction phenomenon was found to be caused by both vortex breakdown and flow separation.
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March 2003
Technical Papers
Influence of Diffuser Angle on a Bluff Body in Ground Effect
Andreas Ruhrmann,
Andreas Ruhrmann
Aeronautics and Astronautics, School of Engineering Sciences, University of Southampton, Southampton SO17 1BJ, UK
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Xin Zhang
Xin Zhang
Aeronautics and Astronautics, School of Engineering Sciences, University of Southampton, Southampton SO17 1BJ, UK
Search for other works by this author on:
Andreas Ruhrmann
Aeronautics and Astronautics, School of Engineering Sciences, University of Southampton, Southampton SO17 1BJ, UK
Xin Zhang
Aeronautics and Astronautics, School of Engineering Sciences, University of Southampton, Southampton SO17 1BJ, UK
Contributed by the Fluids Engineering Division for publication in the JOURNAL OF FLUIDS ENGINEERING. Manuscript received by the Fluids Engineering Division July 16, 2001; revised manuscript received October 7, 2002. Associate Editors: J. Bridges and J. Katz.
J. Fluids Eng. Mar 2003, 125(2): 332-338 (7 pages)
Published Online: March 27, 2003
Article history
Received:
July 16, 2001
Revised:
October 7, 2002
Online:
March 27, 2003
Citation
Ruhrmann , A., and Zhang, X. (March 27, 2003). "Influence of Diffuser Angle on a Bluff Body in Ground Effect ." ASME. J. Fluids Eng. March 2003; 125(2): 332–338. https://doi.org/10.1115/1.1537252
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