Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4993113 | International Journal of Heat and Fluid Flow | 2017 | 20 Pages |
Abstract
The flow around surface-mounted, finite-height square prisms at a Reynolds number of Reâ=â4.2âÃâ104 was investigated experimentally in a low-speed wind tunnel using particle image velocimetry. The thickness of the boundary layer on the ground plane relative to the width of the prism was δ/Dâ=â1.5. Four prism aspect ratios were tested, AR =â9, 7, 5, and 3, to study how the aspect ratio influences the flow field close to the prism. Upstream of the prism, lowering the aspect ratio from AR =â9 to AR =â3 causes the stagnation point on the upstream face to move closer to the free end, but there is no influence on the location and strength of the horseshoe vortex. Lowering the aspect ratio from AR =â9 to ARâ=â3 causes the cross-stream vortices in the upper and lower halves of the wake to move downstream and upstream, respectively; the latter vortex is absent for ARâ=â3, suggesting this prism sits below the critical aspect ratio. Above the free end of the prism, within the region of separated flow, lowering the aspect ratio from ARâ=â9 to ARâ=â3 shifts the location of the cross-stream vortex farther downstream. For the prism of ARâ=â3, reverse flow above the free end is stronger yet more unsteady compared to the more slender prisms, while the streamwise edge vortices are smaller and weaker.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Fluid Flow and Transfer Processes
Authors
D. Sumner, N. Rostamy, D.J. Bergstrom, J.D. Bugg,