Sowby R.,Allen and Luce Inc. |
Sowby R.,SALt Inc |
Sowby R.,Massachusetts Institute of Technology
Journal of New England Water Environment Association | Year: 2015
Culverts have been installed at countless stream crossings in the U.S. as the country's transportation networks have expanded. Unfortunately, many crossings have become barriers to aquatic organism mobility, a function essential to healthy ecosystems. Excessive velocity, outlet drops, and insufficient water depths impede mobility and constrict or sever habitats. Opportunities to reverse this trend continue to arise as aged culverts need to be replaced. Cooperation of public and private partners has led to successful local projects, many of which overlapped with planned infrastructure improvements and community priorities. Four examples from New England demonstrate how culverts can be effectively retrofitted or redesigned to reconnect aquatic habitats while maintaining human uses at each crossing.
Christensen R.T.,Allen and Luce Inc. |
Spall R.E.,Utah State University |
Barfuss S.L.,Utah State University
Journal of Hydraulic Engineering | Year: 2010
The Reynolds-averaged Navier-Stokes (RANS) equations were solved to model flow through two aged pipes at Reynolds numbers ranging from 6,700 to 31,000. Turbulence models employed include the v2-f, realizable k-ε, and k-ω models. The v2-f turbulence model was found to more accurately reproduce available experimental results compared to the k-ε and k-ω turbulence models for flows at R=13,000 and R=31,000, while the realizable k-ε model was most accurate at R=6,700. Much of the error is likely attributable to deficiencies in modeling complex flow structures with flow separation and wall roughness elements smaller than the grid scale. © 2011 ASCE.
Jones S.C.,Allen and Luce Inc. |
Lindhardt P.W.,Oversaw the Implementation of the Logan City Projects |
Sowby R.B.,Allen and Luce Inc.
Journal - American Water Works Association | Year: 2015
Logan City, Utah, experienced first-hand the water-energy nexus when it undertook a comprehensive water and energy audit to determine its best path forward. The city experienced summer water shortages that were attributed to a lack of source capacity. High pressures were also a problem. The proposed solution to solving the fundamental problems was a combination of operational changes and capital projects. The strategy was to split the city into two major pressure zones, which involved installing pressure-reducing valves between zones and reconfiguring two well pump stations. The zone split would alleviate high pressures in the lower zone, which would then reduce water loss and breaks to which crews must respond. The consultant also developed a plan to better use equalization storage. With proper operation, the tanks could fill overnight, using a more affordable off-peak electricity rate. Like giant batteries, the tanks would use low-cost energy to store excess water and then supply it, by gravity, during peak demand.