Browsing by Author "Fu, Alec"

Now showing 1 - 4 of 4
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    Collector Well Study For The Cooling Water Intake System Of The James H. Campbell Electric Power Generating Plant, Unit No. 3
    (Saint Anthony Falls Laboratory, 1978-11) Stefan, Heinz; Fu, Alec
    A 1:24 scale model of the collector well, the central structure of the projected cooling water intake for the James H. Campbell Power Generating Plant, Unit No. 3, on the eastshore of Lake Michigan was built and operated to determine the hydraulic characteristics of the structure. Piezometric pressure distributions and total energy headlosses were measured. Flow patterns and air evacuation characteristics were observed. The total headloss in the 22 ft diameter collector well was determined to be on the order of 4.5 in. for the design flow of 824 cfs. The height of the collector well cover above tbe header axis had to exceed 6 ft in order to avoid formation of a strong vortex in the well. At a height of 11 ft the well performed satisfactorily. Flow rates in the four headers feeding into the collector well deviated by less than 2 per cent from the average. Air entrapped in the dome was evacuated by the £low. Flow from only two headers through the collector was also investigated.
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    Headloss Characteristics of Six Profile-Wire Screen Panels
    (St. Anthony Falls Laboratory, 1978-09) Stefan, Heinz G.; Fu, Alec
    Headloss coefficients for six screen panels manufactured by the Johnson Division UOP, Inc., Minnesota were determined experimentally. The screens are considered for use at the cooling water intake of Consumers Power Company's James H. Campbell Unit No.3. The plant is located on the east shore of Lake Michigan near Grand Rapids, Michigan. The flat screen panels, 24 x 15 inches in size and of differing wire and rod assembly, were tested in a laboratory flume at approach velocities ranging from 0.9 to 2.6 ft/sec. The angle of approach relative to the screen surface was varied from 900 to 450 in intervals of 150 • In the range of velocities and angles tested the headlosses were found to be less than 0.3 ft of water. Headloss coefficients (using approa04 velocity head as a reference) ranged from 0.5 to 2.8 at 900 angle of: ·approach., The experimental data led to the conclusion that the screens tested. would not produce an appreciable'headloss when used in low veloci.ty surface water intakes.
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    Ice Formation On Minnesota Lakes: Use Of Landsat Imagery And Weather Data, To Predict Freeze-Over Dates
    (Saint Anthony Falls Laboratory, 1979-07) Stefan, Heinz; Fu, Alec
    LANDSAT images taken in the fall of 1972, 1973, 1974 and 1975 were analyzed to estimate dates of ice formation on Minnesota lakes. Lakes located in the northern, central and southern parts of Minnesota were studied. Lake surface areas and depths were identified from a lake inventory. The observations derived from the satellite images were compared to theoretical prediction of freeze-over dates based on seasonal heat budget cycles and water temperature cycles. The theory was then applied to all of Minnesota to provide an estimate of average annual freeze-over dates of lakes located in different parts of the state and having different depths. LANDSAT images taken in the Spring of 1976 were analyzed to determine ice break-up dates.
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    Water Temperature Dynamics In Experimental Field Channels: Analysis And Modeling
    (Saint Anthony Falls Laboratory, 1980-06) Stefan, Heinz; Gulliver, John S.; Hahn, Michael G.; Fu, Alec
    This report summarizes some of the morphological, hydraulic, thermal and meteorological characteristics of the experimental field channels at the USEPA Monticello Ecological Research Station. It contains an ,overview of measurements and parameters which characterized the physical operation, conditions of the channels from December 1975 through December 1977. Reported herein are measured values of hydraulic channel roughness, permeability and porosity of rock sections, and thermal diffusivity of bed materials. Recorded water temperatures have been statistically analyzed to . give local diel, longitudinal, and vertical water temperature variations. A data bank of 3-hour water temperature data was established. Mean, standard deviation, skewness, and water temperature values at 5 per cent and 95 per cent probability of occurrence have been calculated on sliding, weekly samples of these 3-hour data. Various aspects of the water temperature regime of the experimental field channels of the USEPA Monticello Ecological Research Station (MERS) were studied theoretically. Longitudinal dispersion and heat transfer relationships which were included in a dynamic water temperature model had to be established. Water temperatures at various channel locations and meteorological parameters were continuously recorded. A convective water surface heat transfer relationship (wind function) was determined from the recorded longitudinal temperature profile and meteorological parameters during quasi-steady state periods. Progressive heat fronts were used with tracer theory to determine longitudinal dispersion coefficients for the field channels. The wind function and the longitudinal dispersion coefficient were incorporated in an implicit finite difference computer model, MNSTREM, for the highly dynamic water temperature prediction in the very shallow field channels. The water temperature model results were verified against 3-hour water temperature measurements over four time periods of up to one month.