Physical models are used to optimize and validate complex hydraulic designs. CFD modeling provides a flexible modeling alternative, saving time and money. The rehabilitation design of Boiling Springs Floodwater Retarding Structure No. 1 (Site No. 1) in Wilburton, Oklahoma, shows how physical modeling can be applied to add confidence to CFD modeling when your spillway rehabilitation requires a specialized design approach.
Boiling Springs Site No. 1 is one of more than 2,100 dams designed and constructed decades ago by the USDA-Natural Resources Conservation Service (NRCS) in Oklahoma that now require upgrades due to downstream development increasing its hazard potential. Boiling Springs Site No. 1 posed the challenge of a constricted site. NRCS-OK and Freese and Nichols, Inc. (FNI) determined that roller-compacted concrete and a cast-in-place box culvert spillway system could be integrated for a specialized solution in a tight space. The cast-in-place box culverts serve as the replacement roadway providing access across the dam for residents. FNI performed computational fluid dynamics (CFD) modeling to design the culvert openings and evaluate the hydraulic effects on the spillway discharge capacity as well as any impacts to computational assumptions and processes for the hydraulics of the stepped spillway. Given the unique box culvert design at the spillway weir crest, it warranted a physical model study to confirm the CFD results. NRCS-OK requested scientists with the USDA-Agricultural Research Service Agroclimate and Hydraulic Engineering Research Unit in Stillwater, OK to evaluate the design with physical modeling. The 1:20 scaled physical model provided visual insight to the spillway performance and verified the CFD modeling results. Flow depth, discharge, and velocity data were recorded at several sections and profiles for the design flow condition. There is good agreement between the physical and numerical models. This presentation will show how the CFD and physical model results in this project align and reinforce each other.
