Multi-Objective optimization of runner blades using a multi-fidelity algorithm

A robust multi-fidelity design optimization methodology has been developed to integrate advantages of high- and low-fidelity analyses and alleviate their weaknesses. The aim of this methodology is to reach more efficient turbine runners with respect to different constraints, in reasonable computational time and cost. In such a framework, an inexpensive low-fidelity (inviscid) solver handles most of the computational burden by providing data for the optimizer to evaluate objective functions and constraint values in the low-fidelity phase. An open-source derivative-free optimizer, NOMAD, explores the search space. Promising candidates are selected among all feasible solutions using a filtering process. The proposed filtering process accounts for Pareto optimal solutions and considers solutions which are different in the design variable space and are dominant in their local territories. A high-fidelity (viscous) solver is used outside the optimization loop to accurately evaluate filtered solutions. Accurate information achieved by high-fidelity analyses is also employed to recalibrate the low-fidelity optimization. The developed methodology demonstrated its ability to redesign a Francis turbine blade for a given best efficiency operating condition. The original and optimized cases were evaluated and compared for a complete range of operating conditions by calculating the efficiency curves and losses of different components. The optimal blade has provided an efficient runner for the given operating conditions considering the design constraints.</jats:p

Determination of Swimming Speeds and Energetic Demands of Upriver Migrating Fall Chinook Salmon (Oncorhynchus Tshawytscha) in the Klickitat River, Washington.

This report describes a study conducted by Pacific Northwest National Laboratory for the Bonneville Power Administration's Columbia Basin Fish and Wildlife Program during the fall of 2001. The objective was to study the migration and energy use of adult fall chinook salmon (Oncorhynchus tshawytscha) traveling up the Klickitat River to spawn. The salmon were tagged with either surgically implanted electromyogram (EMG) transmitters or gastrically implanted coded transmitters and were monitored with mobile and stationary receivers. Swim speed and aerobic and anaerobic energy use were determined for the fish as they attempted passage of three waterfalls on the lower Klickitat River and as they traversed free-flowing stretches between, below, and above the falls. Of the 35 EMG-tagged fish released near the mouth of the Klickitat River, 40% passed the first falls, 24% passed the second falls, and 20% made it to Lyle Falls. None of the EMG-tagged fish were able to pass Lyle Falls, either over the falls or via a fishway at Lyle Falls. Mean swimming speeds ranged from as low as 52.6 centimeters per second (cm s{sup -1}) between falls to as high as 189 (cm s{sup -1}) at falls passage. Fish swam above critical swimming speeds while passing the falls more often than while swimming between the falls (58.9% versus 1.7% of the transmitter signals). However, fish expended more energy swimming the stretches between the falls than during actual falls passage (100.7 to 128.2 kilocalories [kcals] to traverse areas between or below falls versus 0.3 to 1.0 kcals to pass falls). Relationships between sex, length, and time of day on the success of falls passage were also examined. Average swimming speeds were highest during the day in all areas except at some waterfalls. There was no apparent relationship between either fish condition or length and successful passage of waterfalls in the lower Klickitat River. Female fall chinook salmon, however, had a much lower likelihood of passing waterfalls than males. The study also examined energy costs and swimming speeds for fish released above Lyle Falls as they migrated to upstream spawning areas. This journey averaged 15.93 days to travel a mean maximum of 37.6 km upstream at a total energy cost of approx 3,971 kcals (34% anaerobic and 66% aerobic) for a sample of five fish. A bioenergetics example was run, which estimated that fall chinook salmon would expend an estimated 1,208 kcal to pass from the mouth of the Columbia River to Bonneville Dam and 874 kcals to pass Bonneville Dam and pool and the three falls on the Lower Klickitat River, plus an additional 2,770 kcals above the falls to reach the spawning grounds, leaving them with approximately 18% (1,089 kcals) of their original energy reserves for spawning. Results of the bioenergetics example suggest that a delay of 9 to 11 days along the lower Klickitat River may deplete their remaining energy reserves (at a rate of about 105 kcal d{sup -1}) resulting in death before spawning would occur

Ground-water quality for two areas in the Fort Peck Indian Reservation, northeastern Montana, 1993-2000 /

Shipping list no.: 2004-0076-P."December 2003."Includes bibliographical references (p. 15).Mode of access: Internet