Engineering Commons^™

Unsteady-Flow Modeling For Emergency Shutdown Of The Cap Canal, Bert Clemmens, Brian Wahlin, Marcus Shapiro, Patrick Dent

International Symposium on Hydraulic Structures

The Central Arizona Project (CAP) is designed to bring about 1.9 ML of Colorado River water per year to Maricopa, Pima, and Pinal counties in Arizona. CAP carries water from the Colorado River at Lake Havasu toTucson. The CAP canal system is a 540 km long system of conveyance system aqueducts, tunnels, pumping plants,pipelines and a large reservoir (just north of Phoenix, AZ). Water is pumped uphill from the Colorado River. This study was conducted for the Hayden-Rhodes Aqueduct of the Central Arizona Project (CAP), which starts at the after bay of the Bouse Hill Pumping Plant and extends to …

Managing Dam Safety Risks Related To Hydraulic Structures, W. R. Fiedler

International Symposium on Hydraulic Structures

The Bureau of Reclamation’s Dam Safety Program manages risk for over 300 high and significant hazard dams.When risk estimates for potential failure modes indicate increasing justification to take action to reduce risk, dam safety recommendations are typically made. The dam safety recommendations can focus on collecting additional data/performing studies to better quantify risk or on initiating corrective actions to address well defined risks. Dam safety recommendations within Reclamation’s inventory address a number of different issues, such as those related to internal erosion, flood overtopping of dams and seismic stability of dams. Dam safety recommendations related to hydraulic structure potential failure …

Decision-Making Through Sustainability, F. Pardo-Bosch, A. Aguado

International Symposium on Hydraulic Structures

From immemorial time, dams have contributed significantly for the progress of civilizations. For this reason, nowadays, there is a vast engineering heritage. Over the years, these infrastructures can present some ordinary maintenance issues associated with their normal operation or with ageing processes.

Normally, these problems do not represent an important risk for the structure, but they have to be attended. To do it, owners of dams have to finance many ordinary interventions. As it is impossible to carry out all of them at the same time, managers have to make a decision and select the most “important” ones. However, it …

Water System Operator Training For The Central Arizona Project, Brian Wahlin, Bert Clemmens

International Symposium on Hydraulic Structures

The Central Arizona Project (CAP) is designed to bring about 1.85 billion cubic meters (1.5 million acre-feet) of Colorado River water per year to Maricopa, Pima, and Pinal counties in Arizona. The CAP canal system is a 540-km (336-mile) long system of conveyance aqueducts, tunnels, pumping plants, and pipelines that is monitored and remotely controlled using Supervisory Control and Data Acquisition (SCADA) software from CAP headquarters in Phoenix, AZ. Because the CAP is crucial to the renewable water supply in Arizona, operating the canal effectively is of utmost importance. Typical day-to-day operations for Water System Operators on the CAP involve …

Junction Chamber At Vortex Drop Shaft: Case Study Of Cossonay, G. Crispino, D. Dorthe, T. Fuchsmann, C. Gisonni, M. Pfister

International Symposium on Hydraulic Structures

The drainage network of the city of Cossonay (Switzerland) is currently being adapted for future needs. In particular, it is required to drain increased storm discharges due to a population augmentation, and to provide an adequate concept to overcome unfavorable geotechnical conditions.

Vortex drop shafts are sewer manholes commonly applied in steep urbanized topographies to connect conduits across large elevation differences. In Cossonay, the existing 48 m high vortex drop shaft, with a diameter of 1.5 m, allowed the storm discharge to flow from the city to a watercourse issued at half of the valley height. The discharge capacity was …

Experimental Study Of Head Loss Over Laser Scanned Rock Tunnel, L. R. Andersson, I. A.S. Larsson, J. G.I. Hellstrom, P. Andreasson, A. G. Andersson

International Symposium on Hydraulic Structures

Flow in hydropower tunnels is characterized by high Reynolds number and often very rough rock walls. Due to the roughness of the walls, the flow in the tunnel is highly disturbed, resulting in large fluctuations of velocity and pressure in both time and space. Erosion problems and even partial collapse of tunnel walls are in some cases believed to be caused by hydraulic jacking from large flow induced pressure fluctuations. The objective of this work is to investigate the effects of the rough walls on the pressure variations in time and space over the rock surfaces. Pressure measurement experiments were …

Effects Of Hydraulic Jump Motion On Air Entrainment In Closed Conduits, J. D. Mortensen, J P. Kubitschek

International Symposium on Hydraulic Structures

Air vent systems are designed to protect hydropower penstocks and reservoir outlets under various operating conditions. During an emergency closure of an upstream gate the hydraulic jump that forms downstream of the gate is not stationary and may advance downstream potentially increasing the total air demand. A lab-scale physical model of a general outlet works piping configuration was constructed at Reclamation’s Hydraulics Laboratory in Denver, CO to observe hydraulic jump behavior during emergency gate closures. Parameters including gate discharge, gate closure rate, air vent size, and downstream pipe pressure were tested at two different pipe slopes. Results indicate that the …

Numerical Investigation Of The Flow Field Inside A Manhole-Pipe Drainage System, Md Nazmul Azim Beg, Rita Carvalho, Pedro Lopes, Jorge Leandro, Nuno Melo

International Symposium on Hydraulic Structures

Urban drainage networks contain a large number of structures. Manhole is the most common and the most important as it connects pieces of sewer pipes to form sewer networks. Understanding the hydraulics of a manhole-pipe drainage system is either important as this may sometimes become the bottlenecks of the sewer systems. In this study, the flow structure and flow hydraulics of a specific manhole-pipe sewer system was analysed numerically in view of further research to investigate sediment/ suspended solid transport in the system. The numerical model was compared with discharge and water pressure/depth data from experimental model. Different discharges and …

Determining Optimal Discharge And Optimal Penstock Diameter In Water Turbines, Arturo S. Leon

International Symposium on Hydraulic Structures

Minimizing water consumption for producing hydropower is critical given that overuse of flows for energy production may result in a shortage of flows for other purposes such as irrigation and navigation. This paper presents a dimensional analysis for finding optimal flow discharge and optimal penstock diameter when designing impulse and reaction water turbines for hydropower systems. The objective of this analysis is to provide general insights for minimizing water consumption when producing hydropower. This analysis is based on the geometric and hydraulic characteristics of the penstock, the total hydraulic head and the desired power production. As part of this analysis, …

Predicting Velocity At Limit Of Deposition In Storm Channels Using Two Data Mining Techniques, H. Bonakdari, I. Ebtehaj

International Symposium on Hydraulic Structures

In storm channel system design, the system should have the ability to transfer the entire input flow to the system as well as prevent sediment settling. Existing methods of determining the velocity at limit of deposition are minimum velocity or regression-based equations. Because minimum velocity methods fail to consider the effective flow and sediment transfer parameters, while regression-based equations are not flexible in terms of various hydraulic conditions and they do not perform well. Thus, using such equations leads to a lack of designs with optimum, confident coefficients. In this study, Extreme Learning Machines (ELM) are employed to predict velocity …

Stepped Chute Training Wall Height Requirements, S. L. Hunt, K. C. Kadavy

International Symposium on Hydraulic Structures

Stepped chutes are commonly used for overtopping protection for embankment dams. Aerated flow is commonly associated with stepped chutes if the chute has sufficient length. The aeration and turbulence of the flow can create a significant amount of splash over the training wall if not appropriately accounted for in the design of the structure. According to the United States Department of Agriculture (USDA)-Natural Resources Conservation Service (NRCS) Technical Release 60 Earth Dams and Reservoirs, a structural spillway should be designed to pass the freeboard hydrograph such that it does not cause serious damage to the embankment or the structure itself. …

Cabinet Gorge Dam Spillway Modifications For Tdg Abatement - Design Evolution And Field Performance, S. L. Dunlop, I. A. Willig, G. E. Paul

International Symposium on Hydraulic Structures

Avista is implementing spillway modifications to reduce TDG supersaturation downstream of Cabinet Gorge Dam.The key feature of the modifications is the addition of roughness elements, similar to supercavitating baffle blocks,to break up the spillway jet thereby reducing the depth of plunge and TDG supersaturation. The work is progressing in a step-wise manner. A single bay was modified in 2012 and field tested in 2013. Following the initial field tests, aCFD model was developed to aid in design refinements for the prototype and to improve the design prior to modification of subsequent spillway bays. The prototype demonstrated that spillway modifications are …

Turbulence And Energy Dissipation In The Developing Non-Aerated And The Fully-Developed Aerated Flows On A Stepped Spillway, G. Zhang, H. Chanson

International Symposium on Hydraulic Structures

Stepped spillways are characterised by highly turbulent air-water flows and a large rate of energy dissipation compared to smooth chutes. Herein detailed measurements were performed in both the developing non-aerated and fully-developed air-water flow regions on a large 1V:1H stepped spillway model. In the developing flow region, large total pressure fluctuations and turbulence intensities were recorded next to the pseudo-bottom. Downstream of the inception point, large total pressure fluctuations were recorded which were mainly induced by density fluctuations. The water turbulence intensities in the air-water flow region did not differ significantly from those in the developing flow region. The steps …

Free-Surface Aeration In A Steep Stepped Spillway, G. Zhang, H. Chanson

International Symposium on Hydraulic Structures

Self-aeration has important civil and environmental applications in stepped chutes, ranging from cavitation protection to enhanced air-water mass transfer. Air bubble entrainment occurs when the turbulent stresses in the boundary layer exceed the combined effects of surface tension and buoyancy. The governing equations for air diffusion in the rapidly-varied region next to, and in the gradually-varied region away from the inception point of aeration are introduced. New and existing solutions to these equations are discussed and compared with new experimental data. An analytical model for flow bulking is introduced. The concept of negative diffusivity is discussed.

Physical Modeling Of An Aerating Stepped Spillway, S. Erpicum, M. Lodomez, J. Savatier, P. Archambeau, B. J. Dewals, M. Pirotton

International Symposium on Hydraulic Structures

To mitigate the negative effects on the water quality in the downstream river of a projected large dam, and in particular to increase the dissolved oxygen concentration during low flow periods within the first 10 years of dam operation, an aerating weir has been designed and tested on a physical model at the Laboratory of Engineering Hydraulics (HECE) of the Liege University. The design of the structure has been done considering data from the literature. The selected solution is a 3 m high stepped spillway designed to operate in nappe flow conditions within the range of design discharges (25 – …

Effect Of Deflector Aerator On Stepped Spillway Flow, Stéphane Terrier, Michael Pfister, Anton J. Schleiss

International Symposium on Hydraulic Structures

Systematic physical model tests are performed on a stepped spillway equipped with a bottom aerator at the beginning of the stepped part. A deflector is used to issue a jet in order to initiate air entrainment into the flow. A horizontal slot located in the vertical face of the first step allows for air supply underneath the flow. The cavity subpressure was measured to ensure optimal aerator performance, namely atmospheric pressure conditions. The air discharge entrained below the jet is measured to derive the aerator air entrainment coefficient. The local air concentrations are spatially measured downstream of the aerator at …

Tsallis Entropy Theory For Hydraulic Modeling, Vijay P. Singh

International Symposium on Hydraulic Structures

Hydraulic structures serve a multitude of human needs. They are needed for water supply, water transfer, water diversion, irrigation, land reclamation, drainage, flood control, hydropower generation, river training, navigation, coastal protection, pollution abatement, and transportation. Many of the structures, such as channels, culverts, and impoundments, have been with us since the birth of human civilization; some, such as spillways, dams, and levees, are more than two centuries old; and some are of more recent origin. In the beginning, structures were designed more or less empirically. Then, engineering and economics constituted the sole foundation of design. Nearly fifty years ago, planning …

Columbia River Treaty And System Reservoir Operations, Pete Dickerson

International Symposium on Hydraulic Structures

The river headwaters of the Columbia River originate in British Columbia and ultimately enter the Pacific Ocean near Astoria, Oregon (1,214 miles). About 15% of the basin is in Canada, and 35% of the average annual flow comes from Canada (as measured at The Dalles, Oregon). Historically, the largest flood run-offs occur in the spring, primarily driven by snowmelt. The basin has the most hydropower capacity, ~37 GW, in North America. U.S. federal projects are authorized to meet multiple purposes: flood risk, hydropower, fish and wildlife, navigation, irrigation, recreation, and municipal and water supply.

Colorado River System - Planning And Operations During Extended Drought, Daniel Bunk

International Symposium on Hydraulic Structures

Today, between 35 and 40 million people rely on the Colorado River and its tributaries for some, if not all, of their municipal water needs. These same water sources irrigate nearly 4.5 million acres (1.8 million hectares) of land within the basin and adjacent areas that receive Colorado River water. The Colorado River and its tributaries also provide essential cultural and economic resources to 22 federally recognized tribes, as well as recreational opportunities and environmental benefits to 11 National Park Service units and seven national wildlife refuges. Additionally, the Colorado River is a vital resource to the United Mexican States …

Management Of River System Flows, Keil Neff

International Symposium on Hydraulic Structures

The Tennessee Valley Authority (TVA) operates a system of 49 dams and reservoirs in the Tennessee River and Cumberland River watersheds of the southeastern United States. TVA operates this system for the purposes of navigation, flood control and power production; management of water supply, water quality and aquatic habitat; and recreation and other public benefits. TVA, created by the U.S. Congress under the TVA Act of 1933, is the largest public power supplier in the U.S. and is fully self-financed with no federal appropriations. The Tennessee River is the only basin in the U.S. that is operated by a single …

Reconfiguring, Replumbing, And Repurposing Hydraulic Structures - Responding To New Realities, P. H. Burgi

International Symposium on Hydraulic Structures

We look into an ever-changing future filled with challenges to continue developing new water resources but with an increased emphasis on water conservation and preserving our natural environment. This is a different approach to that of the 20^th century, where the emphasis was generally on development of water resources. As water engineers and managers facing an increasingly limited water supply, our challenge is to build, and in some cases change, infrastructure for a resilient future. The built infrastructure for water systems must protect life and provide a safe living environment, including an adequate supply and quality of fresh water. …

Model For Computing Kinetics Of The Graphene Edge Epitaxial Growth On Copper, Mikhail Khenner

Mathematics Faculty Publications

A basic kinetic model that incorporates a coupled dynamics of the carbon atoms and dimers ona copper surface is used to compute growth of a single-layer graphene island. The speed of theisland's edge advancement on Cu[111] and Cu[100] surfaces is computed as a function of the growthtemperature and pressure. Spatially resolved concentration pro les of the atoms and dimers aredetermined, and the contributions provided by these species to the growth speed are discussed.Island growth in the conditions of a thermal cycling is studied.

Oversampling Methods For Imbalanced Dataset Classification And Their Application To Gynecological Disorder Diagnosis, Iman Nekooeimehr

USF Tampa Graduate Theses and Dissertations

In many applications, the dataset for classification may be highly imbalanced where most of the instances in the training set may belong to some of the classes (majority classes), while only a few instances are from the other classes (minority classes). Conventional classifiers will strongly favor the majority class and ignore the minority instances. The imbalance problem can occur in both binary data classification and also in ordinal regression. Ordinal regression is a supervised approach for learning the ordinal relationship between classes. Extensive research has been performed for addressing imbalanced datasets for binary classification; however, current methods do not address …

Enforcing Security Policies On Gpu Computing Through The Use Of Aspect-Oriented Programming Techniques, Bader Albassam

USF Tampa Graduate Theses and Dissertations

This thesis presents a new security policy enforcer designed for securing parallel computation on CUDA GPUs. We show how the very features that make a GPGPU desirable have already been utilized in existing exploits, fortifying the need for security protections on a GPGPU. An aspect weaver was designed for CUDA with the goal of utilizing aspect-oriented programming for security policy enforcement. Empirical testing verified the ability of our aspect weaver to enforce various policies. Furthermore, a performance analysis was performed to demonstrate that using this policy enforcer provides no significant performance impact over manual insertion of policy code. Finally, future …

Quantum Random Number Generation Using A Quanta Image Sensor, Emna Amri, Yacine Felk, Damien Stucki, Jiaju Ma, Eric Fossum

Dartmouth Scholarship

A new quantum random number generation method is proposed. The method is based on the randomness of the photon emission process and the single photon counting capability of the Quanta Image Sensor (QIS). It has the potential to generate high-quality random numbers with remarkable data output rate. In this paper, the principle of photon statistics and theory of entropy are discussed. Sample data were collected with QIS jot device, and its randomness quality was analyzed. The randomness assessment method and results are discussed.

A New Application Of Machine Learning In Health Care, Kaj Mikael Björk, Yoan Miche, Emil Eirola, Amaury Lendasse

Engineering Management and Systems Engineering Faculty Research & Creative Works

In Our Ever More Complex World, the Field of Analytics Has Dramatically Increased its Importance. Gut Feeling is No Longer Sufficient in Decision Making, But Intuition Has to Be Combined with Support from the Huge Amount of Data Available Today. Even If the Amount of Data is Enormous, the Quality of the Data is Not Always Good. Problems Arise in at Least Two Situations: I) the Data is Imprecise by Nature and Ii) the Data is Incomplete (Or There Are Missing Parts in the Data Set). Both Situations Are Problematic and Need to Be Addressed Appropriately. If These Problems Are …

Computational Code For Optimization Of Thermal Treatment Of Fine Grained Soils As A Method Of Expediting Their Load Induced Consolidation, Radhavi Abeysiridara Samarakoon

USF Tampa Graduate Theses and Dissertations

Construction in soft soils has been a challenging task for engineers due to the excessive time taken for dissipation of construction induced pore water pressure and the ensuing postconstruction settlement. Use of vertical drains has proven to be an effective and economical method for soft ground improvement and hence extensive research has been carried out to further improve its efficiency. Effect of temperature on radial consolidation is one aspect of such research among many others that have been pursued.

Elevated temperature certainly has a pronounced effect on the hydraulic conductivity due to the reduction it causes in the viscosity of …

Electrospinning Of Polymeric Solutions Using Opuntia Ficus-Indica Mucilage And Iron Oxide For Nanofiber Membranes For Treating Arsenic Contaminated Water, Venkatesh Eppili

USF Tampa Graduate Theses and Dissertations

Water is the essential part of every organism and it is also a vital constituent of healthy living and diet. Unfortunately water contamination over the past decade has increased dramatically leading to various diseases. As technology advances, we are detecting many pollutants at smaller levels of concentrations. Arsenic (As) is one of those major pollutants, and Arsenic poisoning is a condition caused due to excess levels of arsenic in the body. The main basis for Arsenic poisoning is from ground water which naturally contains high concentrations of arsenic. A case study from 2007 states that over 137 million people in …

A Life Cycle Assessment Of A Uranium Mine In Namibia, Janine Lambert

USF Tampa Graduate Theses and Dissertations

Uranium mining and nuclear power is a controversial topic as of late, especially in light of the recent Fukushima event. Although the actual use of nuclear fuel has minimal environmental impact, its issues come at the very beginning and end of the fuel’s life cycle in both the mining and fuel disposal process. This paper focuses on a life cycle analysis (LCA) of uranium mine in the desert nation of Namibia in Southern Africa. The goal of this LCA is to evaluate the environmental effects of uranium mining. The LCA focuses on water and energy embodiment such that they can …

Application And Analysis Of Asymmetrical Hot And Cold Stimuli, Ahmad Manasrah

USF Tampa Graduate Theses and Dissertations

The human body has a unique mechanism for perceiving surrounding temperatures. When an object is in contact with the skin, we do not feel its temperature. Instead, we feel the temperature change that is caused on our skin by that object. The faster the heat is transferred, the more intense the thermal sensation is. In this dissertation, a new dynamic thermal display method, where different rates of warm and cold are applied on the skin to generate a unique sensation, is presented. The new method can be related in a wide range of applications including thermal haptics and virtual reality. …