Civil Engineering Papers
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Item Open Access Behavior of LNG vapor clouds: tests to define the size, shape and structure of LNG vapor clouds(Colorado State University. Libraries, 1980-07) Meroney, Robert, N., author; Neff, D. E., author; Kothari, K. M., author; Fluid Mechanics and Wind Engineering Program, Department of Civil Engineering, Colorado State University, publisherA terraced 1:240 scale model of the China Lake Naval Weapons Center was constructed to a resolution of one foot vertical increments and placed in the wind tunnel to determine the distances of lower flammability limit (LFL) for 1980, 40 cubic meter spills of Liquefied Natural Gas (LNG) under 4 wind speeds, 5 wind directions, and neutral flow conditions. A set of 8 aspirated hot-wire katharometer probes were made to determine the transient concentration at various downwind locations. Measurements of mean velocities, turbulence intensities, velocity spectra and correlations were performed over the model in the wind tunnel capable of simulating atmospheric phenomena. Data analysis has produced peak concentrations, contours of LFL, and time progressions of the plume ground level LFL. The wind tunnel test should determine the locations of meteorological or concentration instruments set up for field tests. In addition, the expected distances to LFL are determined by wind tunnel tests, thus the field program has the prior knowledge of the distances up to which the measurements should be performed.Item Open Access Evapotranspiration in the tropics(Colorado State University. Libraries, 1970) Schulz, E. F., author; Hossain, Aolad, author; Colorado State University, publisherA study was made of monthly rainfall and runoff over a 105,000 square kilometer watershed in northern Thailand. The function of the watershed in producing the runoff hydrograph was simulated using a type of Stanford Watershed Model adapted for operation with an IBM 1130 digital computer. The evapotranspirational losses from the watershed were computed by using the Thornthwaite, Penman, Blaney-Criddle and Blaney-Morin methods of computing the evapotranspiration. By comparing the computed runoff with the observed runoff from the watershed, it is shown that the model most nearly predicted the observed runoff when the Penman or Blaney-Morin methods were used to estimate the evapotranspirational losses. It was concluded that for a tropical environment, evapotranspirational estimates must include a term measuring the relative humidity of the atmosphere. The evaporation of water is often limited by the ability of the atmosphere to carry away the water vapor produced. Those methods of estimating evapotranspiration based only on temperature and radiation or sunshine data consistently over-estimate the evapotranspiration from a tropical watershed.Item Open Access Dimensionless unit hydrographs from tropical watersheds(Colorado State University. Libraries, 1969?) Schulz, E. F., author; Colorado State University, publisherThe problem of estimating flood peaks from small watersheds is involved in the design of storm sewers highway drainage, diversion works, bridges and culverts. The majority of such hydraulic structures are constructed on small watersheds, since small streams have not been gaged in the past as extensively as in the case of large streams, more of the designs have to be prepared without the benefit of stream flow records. In the design of many hydraulic structures the engineer is concerned not only with the maximum discharge but also with the total volume of runoff and its distribution with respect to time, i. e., the entire runoff hydrograph.