AN EXPERIMENTAL STUDY OF FLOW AROUND SURFACE-MOUNTED PYRAMIDS

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AN EXPERIMENTAL STUDY OF FLOW AROUND
SURFACE-MOUNTED PYRAMIDS
Background
Flow around surface-mounted pyramids is of great
engineering and fundamental importance. It
represents the flow around mountains, hills,
buildings and electronic components.
Objective
Different experimental methods were used to
measure velocity and pressure fields, as well as
to visualize the flow, in order to characterize
the flow field.
Vortex shedding from a pyramid (top). Formation
of the horseshoe vortex upstream of the pyramid
(lower).
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Research Carried Out

• Velocity Field from
• PIV (Particle Imaging Velocimetry)
• LDV (Laser Doppler Velocimetry)
• HWA (Hot Wire Anemometry)
• Pressure Field
• Oil-Film Visualization
• Smoke In Laser Sheet
• LIF (Laser Induced Fluorescence)
• in Water

Oil-film image and pressure contours (left), PIV
velocity field (right) around pyramid (apex
angle, ? 60, angle of attack 0)
Key Findings
Periodicity in the wake of slender pyramids
(15lt?lt75), due to regular vortex shedding. Wind
loading on the pyramid is independent of the
orientation. A new length scale for the ground
pressure profiles around pyramids and other bluff
bodies.
3-D presentation of the vortical structures
around a pyramid