The force and pressure behavior of a generic diffuser in ground effect were investigated. The diffuser model is a bluff body with a rear diffuser at 17 deg to the horizontal, and side-plates. Measurements were conducted in a low speed wind tunnel equipped with a moving ground facility. Techniques employed were force balance, pressure taps, and surface flow visualization. The diffuser flow in ground effect was characterized by vortex flow and three-dimensional flow separation. Four types of force behavior were observed: (a) down-force enhancement at high ride heights characterized by an attached symmetric diffuser flow, (b) maximum down-force at moderate ride heights characterized by a symmetric diffuser flow and separation on the diffuser ramp surface, (c) down-force reduction at low ride heights characterized by an asymmetric diffuser flow and flow separation, and (d) low down-force at very low ride heights, also characterized by an asymmetric diffuser flow and flow separation. The down-force reduction near the ground is attributed to flow separation at the diffuser inlet and subsequent loss of suction in the first half of the diffuser.
The Force and Pressure of a Diffuser-Equipped Bluff Body in Ground Effect
Contributed by the Fluids Engineering Division for publication in the JOURNAL OF FLUIDS ENGINEERING. Manuscript received by the Fluids Engineering Division April 27, 2000; revised manuscript received October 3, 2000. Associate Editor: K. Zaman.
- Views Icon Views
- Share Icon Share
- Search Site
Senior, A. E., and Zhang, X. (October 3, 2000). "The Force and Pressure of a Diffuser-Equipped Bluff Body in Ground Effect ." ASME. J. Fluids Eng. March 2001; 123(1): 105–111. https://doi.org/10.1115/1.1340637
Download citation file: