A coupled 1D and 2D hydrodynamic model for small rivers and streams on a large background area using an immersed boundary method (IBM) was developed and implemented for a simple flooding case in a previously published study. In this study, the IBM model was applied for simulations on a real geographical area, the Calcasieu Lake and its surrounding area in Southwest Louisiana. The simulation area ranges from the city of Lake Charles on the north to Gulf of Mexico on the south, and two National Wildlife Refuges (NWR) on the east and west side of Calcasieu Lake. A small change in the natural state of Calcasieu Lake, i.e. the change in the water surface elevation or flooding, can have a drastic impact on the ecosystem of its surrounding wetlands. The flooding to the wetlands is mainly through small rivers connected to the lake. In order to study the effects of coastal flooding to the wetlands, the IBM 1D-2D coupled model was implemented in the simulation package. The main purposes of this study are to: 1) determine the appropriate number of immersed boundary points to be used for this simulation, 2) test the applicability and validate the IBM model for an actual geographical region. Due to the lack of measurement data for the small rivers, the validation was conducted by comparing simulated results from IBM to the results from a non-IBM approach (i.e., manually carved rivers). Data from NOAA and USGS were used for the boundary conditions for the 2D model.

In this study, a hydrodynamic and a salinity transport models were developed for simulations of Sabine Lake water system located on the Texas-Louisiana border. The target simulation area includes several major water bodies, such as Sabine Lake, Sabine River, Sabine Pass, Sabine Neches Canal (Ship Channel), and part of Gulf Intracoastal Waterway (GIWW) and Sabine River Diversion Canal (SRDC). The SRDC supplies fresh water to the area industry, mainly petrochemical. High salinity in SRDC could significantly affect the daily production of the industry. Two-dimensional (2D) depth-averaged shallow water equation set and 2D depth-averaged salinity transport equation were used for developing the hydrodynamic and salinity transport numerical models in order to carry out the simulation. The major purposes of this study are to calibrate and validate hydrodynamic and salinity transport models in order to assess and predict the salinity in SRDC under severe weather conditions such as hurricane storm surges in future study. Measurement data from National Oceanic and Atmospheric Administration (NOAA) and United States Geological Survey (USGS) were used to calibrate the boundary conditions as well as to validate the model. Boundary conditions were calibrated at locations in Sabine Pass and in the north edge of the lake by using water–surface elevation data. Hydrodynamic model was validated at the USGS location using water–surface elevation data. Then, the simulation estimations of water surface level and salinity were compared at three locations, and the results show the accuracy of the validated model. Parallel computing was conducted in this study as well, and computational efficiency was compared.

The world is facing an imminent energy crisis. In order to sustain our energy supply, it is necessary to advance renewable technologies. Despite this urgency, however, it is paramount to consider the larger environmental effects associated with using renewable resources. Hydropower, in the past, has been seen as a viable resource to examine, given that its basics of mechanical to electrical energy conversion seem to have little effect on the environment. Discrete analysis of dams and in-stream diversion set-ups, although, has shown otherwise. Modifications to river flows and changes in temperature (from increased and decreased flows) cause adverse effects to fish and other marine life because of changes in their adaptive habitat. Recent research has focused on kinetic energy extraction in river flows, which may prove to be more sustainable, as this type of extraction does not involve a large reservoir or large flow modification. The field of hydrokinetic energy extraction is immature; little is known about the devices’ performance in the river environment and their risk of impingement, fouling, and suspension of sediments. The governing principles of hydrokinetic energy extraction are presented, along with a two-dimensional computational fluid dynamics (CFD) model of the system. Power extraction methods are compared and CFD model validation is presented. It is clear that more research is required in hydrokinetic energy extraction with an emphasis toward lower environmental and ecological impacts.

Quenched and tempered plate steel is capable of modified cup-and-cone fractures involving one or more longitudinal cracks “parallel” to the flat plate surfaces. The occurrence was verified by tensile testing of three steels at a variety of temperatures. Electron fractography revealed that quasi-cleavage, shear lips, tearing, and normal rupture were active, being identified by modified river patterns and by elongated and equiaxed dimples resulting from the coalescence of microvoids. The brittle longitudinal cracks are formed shortly before final rupture. Application of the Bridgman plasticity solution for necked tensile specimens shows that the split, layered, fracture occurs under unique stress conditions.

The author shows that even in steady uniform turbulent channel flow there exist on the average mean accelerations and forces acting on fluid particles. These are computed from the flow equations and Laufer’s data. There exist both normal and axial mean accelerations, the latter highly negative (15g and more) in the dissipative “transition” layer near the wall, elsewhere constant. There most river bed-load and dune sand movement occurs. Mixing and sediment transportation are explained dynamically. Mean shear is shown to exist mainly in the dissipative layer. Mean turbulent trajectories are defined.

This paper describes the new adjustable blade, single-speed, vertical, single-runner reversible pump-turbine units recently developed and placed into service at Ontario Hydro’s forebay storage pumping-generating station at the S.A.B. Power Project on the Niagara River. The units operate under unusual variations in head. In the pumping sequence the limits are 59 and 90 ft and in the turbine cycle from 45 to 85 ft. Tailwater depression is not required on start-up. Change-over from turbine to pumping sequence is accomplished in a matter of minutes and occurs several times each day. Data are given on the performance requirements for capacity and efficiency versus hydraulic operating conditions of head, tail water, and forebay reservoir levels. Information in the paper includes unusual features of mechanical design.