Abstract: Several practical refinements, extensions, additions, and improvements to the manufactured three-dimensional continuous convex-concave fairing with attached vortex generators are provided. The piecewise continuously varying slope and curvature fairings provide manufacturing cost reductions, as well as cost reductions by reducing the frequency and complexity of monitoring practices for bridges and elimination of temporary fixes that require costly annual or periodic engineering studies and construction to mitigate scour on at-risk bridges. The probability of bridge failure and its associated liability to the public is totally avoided since the root cause of local scour is prevented.

Abstract: Discussed are several practical cost-effective refinements, extensions, additions, and improvements to the manufactured three-dimensional convex-concave fairing with attached vortex generators that was disclosed by Simpson et al. (U.S. Pat. No. 8,348,553). Extensions are disclosed for bridge piers and abutments at larger angles of attack of up to 45°, for piers and abutments downstream of a bend in a river where there is large-scale swirling approach flow, and for piers in close proximity to an adjacent pier of abutment.

Abstract: An asymmetric tetrahedral vortex generator that provides for control of three-dimensional flow separation over an underlying surface by bringing high momentum outer region flow to the wall of the structure using the generated vortex. The energized near-wall flow remains attached to the structure surface significantly further downstream. The device produces a swirling flow with one stream-wise rotation direction which migrates span-wise. When optimized, the device produces very low base drag on structures by keeping flow attached on the leeside surface thereof. This device can: on hydraulic structures, prevent local scour, deflect debris, and reduce drag; improve heat transfer between a flow and an adjacent surface, i.e., heat exchanger or an air conditioner; reduce drag, flow separation, and associated acoustic noise on airfoils, hydrofoils, cars, boats, submarines, rotors, etc.

Abstract: Disclosed is a manufactured three-dimensional convex-concave fairing with attached vortex generators, for hydraulic structures such as bridge piers and abutments, whose shape prevents the local scour problem around such hydraulic structures. The device is a conventionally made concrete or fiber-reinforced composite, or combination of both, vortex generator equipped hydrodynamic fairing that is fit or cast over an existing or new hydraulic structure around the base of the structure and above the footing. The vortex generators are positioned so as to energize decelerating near wall flow with higher-momentum outer layer flow. The result is a more steady, compact separation and wake and substantially mitigated scour inducing vortical flow.