The flow field inside an orifice flowmeter with a beta ratio of 0.50 operating at a Reynolds number of 91,100 has been studied using a three-color,

No abstract

A recently developed version of a swirl-flow finite difference computer code was improved and employed in predicting the compressible flow of air through generic labyrinth seals. The cavity-by-cavity flow field development from the seal inlet is computed, and the distribution of various field variables is examined. Results are given for straight-through seals of corresponding teeth-on-stator and teeth-on-rotor types. The teeth-on-rotor seal gives greater leakage resistance than the equivalent teeth-on-stator design. Also, it exhibits a greater swirl velocity development. These previously unavailable predictions of swirl velocity development are provided for the refinement of simpler models, as investigators have asked for these results.

The southern reach of Biscayne Bay (South Bay) is formed by Card Sound, Barnes Sound, and adjacent waters, which experience direct tidal exchange with the Florida Straits through a series of natural inlets into Card Sound. These inlets include Angelfish Creek, Broad Creek, and Caesar Creek (known as the ABC's). Barnes Sound is isolated from direct ocean tidal influence. This southern portion of the bay exhibits a complicated pattern of tidal exchange and wind-driven cur¬ rents. Water can enter and leave this area through any of the several mentioned natural inlets exchanging with the Florida Straits to the east, to the Central Bay to the north, or through Jewfish Creek to Florida Bay to the south. Several small connections from Manatee Bay to Long Sound in Florida Bay also exist through culverts under U.S. Highway 1. The present day salinity of Biscayne Bay is governed by the addition of small volumes, compared to the tidal prism, of fresh water from various sources (pri¬ marily canals, rainfall, and groundwater) combined with the influence of tidal exchange with the Florida Straits through various inlets and channels and winddriven circulation. In general, the isohalines tend to align themselves in a northsouth direction, with the fresher water remaining closer to the western shoreline. The north-south alignment changes with inflow patterns, usually seasonally, with the isohalines shifting seaward or landward, depending on the amount of fresh 2 Chapter 1 Introduction 4 Chapter 1 Introduction Features of present effort Although each of the models previously discussed has merit, there are several features unique to the model presented in this report that make it suitable for the evaluation of freshwater impacts on Biscayne Bay. These include: a. The inclusion of South Bay and North Bay in the model domain. b. The extension of the ocean boundaiy eastward from the Safety Valve to a point several miles offshore, thereby minimizing the impact of boundary effects on the model results (especially salinity results). c. High grid resolution, especially in the nearshore. d. The simultaneous inclusion of groundwater inflow, rainfall/evaporation, and wind in the boundaiy forcing.

The one-dimensional HEC-RAS multi-purpose open channel flow modeling software was successfully used, with ArcMap and HEC-GeoRAS, to simulate flow over the Wappapello Dam limited-use Ogee spillway (Wappapello, Missouri). Initial computational hydraulic modeling results predicted a lake elevation of 132.9 m (405.0 ft) [NAVD 1988] would be required for the resulting floodwaters overtopping the spillway to reach the nearby Wappapello Lake Management Office. An intense rainfall event during 2011 led to the spillway being overtopped for the first time since 1945. Spillway performance during the 2011 event was analyzed afterwards. Results indicated that the spillway crest was not submerged by backwater. A technique was employed which successfully estimated the design energy head of 7.160 m (23.49 ft) for the spillway. Hydraulic modeling developed after the 2011 event incorporated this estimated design energy head, allowing the spillway discharge coefficient to vary with discharge in the course of an unsteady modeling run. Results indicated that, while the spillway did perform as designed, the performance is limited by the shallow approach depth.