Civil and Environmental Engineering Commons^™

Estimation Of The Efficiency Of Hydraulic Pumps, A. Martin-Candilejo, D. Santillán, L. Garrote

International Junior Researcher and Engineer Workshop on Hydraulic Structures

A sustainable design of water supply systems needs to account operational costs. When pumping is required, the energy consumed by the pumps plays a major part in the operational costs, and the efficiency of the pumps can greatly affect the energy expenses. How to properly estimate the value of pump efficiency is hence of great importance. The aim of this study is to study in depth the efficiency of hydraulic pumps, in relation with the other design variables (flow rate, pumping head, power, etc.). For that, 400 hydraulic pumps were analysed. A strong relationship between the flow rate and the …

Streamflow Duration Curves: Focus On Low Flows, E. Carcano, M. Betasolo

International Junior Researcher and Engineer Workshop on Hydraulic Structures

Flow duration curves (FDCs) express the link between a selected streamflow and the percentage in time such value is exceeded. The curves provide a graphical insight into hydrological regimes, though, the absence of time-series data is a significant shortcoming. Conversely to what happens with hygrograms, flows in FDCs are represented without regard of sequence of occurrence. This paper explores FDCs of 19 catchments for which, at least, 10 years of daily discharges are available. FDCs can be built for any temporal scale (i.e. daily, weekly, monthly). In this study daily discharges have been adopted because daily scale better represents the …

Flow Distribution In Slotted Pipe Bottom Outlets, Felipe Azevedo Paulo, Eder Daniel Teixeira

International Junior Researcher and Engineer Workshop on Hydraulic Structures

Reservoir sedimentation is a major threat to dam operation. It can reduce water storage capacity, clog water intakes, and damage turbine components. Flushing operations by bottom outlets are a mitigation measure that allows removing sediment deposited near the dam. Unfortunately, the effect of such structures is localized if no water level draw down takes place; therefore, investigations of new designs that improve sediment removal have emerged recently. In this work, we present our current results on the investigation of the slotted pipe bottom outlet obtained through numerical modeling. The flow patterns were characterized for different water levels, showing that discharges …

Calibration Of A Hydraulic Model For Seasonal Flooding In A Lowland River With Natural Diversions And Bathymetric Uncertainty, For Dam Downstream Impact Assessment, Getachew E. Mamo, Davide Motta, Martin Crapper

International Junior Researcher and Engineer Workshop on Hydraulic Structures

A method is developed to generate bank-full river main channel geometry, to complement an open-source Digital Elevation Model (DEM) and produce a calibrated hydraulic model reproducing the extent of historically observed overbank flooding. This approach relies on limited surveyed cross section and flow rate information and is potentially suitable for projects in developing countries where the availability of measured data is limited. The method presented is applied to the case of the seasonal flooding of the Baro River in the Gambela floodplain in Ethiopia, modelled with a two-dimensional hydraulic model. The simulated flooding extent for the 1990 wet season is …

Particle Image Velocimetry (Piv) Investigation Of Local Scour Around Emergent And Submerged Circular Cylinders, P. Williams, R. Balachandar, V. Roussinova, R. Barron

International Junior Researcher and Engineer Workshop on Hydraulic Structures

Analysis of the velocity field surrounding a circular cylinder under equilibrium of local scour has been restricted due to practical limitations of commonly used measurement techniques. This investigation summarizes select cases in the literature which have attempted to circumvent such limitations and presents flow field measurements using Particle Image Velocimetry (PIV). Scour tests were conducted in a horizontal flume fitted with a sediment recess containing erodible bed material. Tests were conducted with both emergent and submerged circular cylinders for a period of 24 hours, after which equilibrium was achieved and planar PIV measurements were obtained in the streamwise-vertical symmetry plane. …

Comparison Of Pressure Distribution In 2d And 3d Jet-Driven Scour Processes, Simone Pagliara, Deep Roy

International Junior Researcher and Engineer Workshop on Hydraulic Structures

Water jets impacting on a non-cohesive granular bed cause a dynamic pressure distribution on the surface of the scour hole. Such distribution greatly differs from the hydrostatic one, especially in proximity of the impact zone, where the kinetic energy of the jet is dissipates due to the shear stresses acting on the scour surface. Here, the excess of shear stress causes the erosion of the bed material and can lead to the failure of hydraulic structures. Therefore, a detailed analysis of the forces acting on the scour surface is fundamental to understand the erosion mechanisms. Experimental tests were conducted under …

Modelling Velocity Profiles Of Aerated Flows Down Grassed Spillways, H. Cui, S. Felder, M. Kramer

International Junior Researcher and Engineer Workshop on Hydraulic Structures

The ecological and environmental benefits of grassed spillways present a green solution to the construction of low head conveyance structures. On a grassed spillway, the aggregate of the grass canopy and root structure may alter flow resistance, velocity distribution and other flow properties. While subcritical flows in vegetated open channels have been extensively researched, only little is known about flow properties in supercritical high-velocity flows, which are typically characterized by self-aeration. The current study explores the application of a velocity superposition to supercritical aerated flows on a spillway with artificial grass. Velocity measurements were conducted with a Pitot tube and …

A Critical Analysis Of Jet-Induced Scour Formulas, J. Di Nardi, M. Palermo, S. Pagliara

International Junior Researcher and Engineer Workshop on Hydraulic Structures

Many studies investigate erosive processes occurring in non-cohesive granular materials downstream of grade-control structures, dam spillways, headcuts, and other hydraulic structures. Because of the complexity of the scour mechanism, the analysis of the scour phenomenon caused by plunging jets is generally conducted by using physical models and particularly for specific structure geometries. In this regard, many researchers proposed empirical approaches to estimate the main scour lengths, but their contributions are limited to tested conditions and cannot be generalized. This lack of generality has been (partially) overcome by other, more recent, approaches, that are either semitheoretical or fully theoretical. Previous works …

Numerical Simulation Of Fish Passage Over A Weir, Linus Kaminski, C. Thorenz, R. Weichert

International Junior Researcher and Engineer Workshop on Hydraulic Structures

Downstream migration over weir structures has been a mostly neglected element of ecological continuity in the last decades. The guidelines currently applied in Germany to prevent damage to fish do not sufficiently consider the conditions present at weirs. To improve knowledge of the risks of fish passage over a weir due to physical strike, pressure changes and shear stress, a numerical method using the three-dimensional computational fluid dynamics package OpenFOAM® was developed to simulate fish passage over a weir by tracking passively transported particles. In this study, the method is tested on an overshot and an undershot weir and the …

Effect Of Boundary-Layer Development On The Water-Surface Fluctuations Of Supercritical Flow Below A Sluice Gate, Ryugen Satoh, M. Takahashi, I. Ohtsu

International Junior Researcher and Engineer Workshop on Hydraulic Structures

Hydraulic structures with a sluice gate are commonly used for control of the flow. In supercritical flow below a sluice gate, an accurate estimation of the water depth and boundary layer thickness is important for the hydraulic design of a horizontal apron. The relation between water-surface fluctuations and boundary-layer development has not been clarified. The aim of this paper is to experimentally demonstrate the effect of boundary-layer development on water-surface fluctuations of supercritical flow below a sluice gate. It is shown that water surface begins to fluctuate slightly upstream of the critical point. The water-surface fluctuations and turbulence intensities downstream …

Cfd Simulation Of Supercritical Flow In Narrow Channels Including Sediment Bypass Tunnels, Subhojit Kadia, Elena Pummer, Nils RüTher

International Junior Researcher and Engineer Workshop on Hydraulic Structures

Secondary currents, turbulence characteristics and bed shear stress distribution are the crucial parameters for specifying sediment transport. Hence, to understand the sediment transport in sediment bypass tunnels (SBTs), we performed computational fluid dynamics (CFD) simulation of supercritical flow in a narrow straight channel. The results of the steady state simulation (Froude number ≈ 1.8) were compared with experimental results. The commonly used two-equations linear eddy-viscosity models are limited to isotropic turbulence closure and hence could not replicate the desired secondary currents. Therefore, the LRR Reynolds Stress Model was used, and predicted the flow features and the secondary currents (three kinds …

Probability Of Woody Debris Passage At Rock Weirs, Kathryn A. Margetts, B. M. Crookston

International Junior Researcher and Engineer Workshop on Hydraulic Structures

Often, large woody debris (LWD) at hydraulic structures is considered hazardous from a performance and public safety perspective. However, the sustainable management of rivers requires the consideration of ecological impacts of LWD such as cover for aquatics and the natural movement of LWD through a catchment. Therefore, this study explores the interaction of natural (nonuniform) LWD with rock weirs through field observations in the Blacksmith Fork River in Utah, USA and laboratory testing at the Utah Water Research Laboratory. The passage probability of individual LWD at rock weirs is observed and tested in an effort to describe the balance between …

Laboratory Experiments On Long Waves Interacting With Rigid Vertical Cylinders, R. Basile, F. De Serio, D. Raffaele

International Junior Researcher and Engineer Workshop on Hydraulic Structures

The impact of waves caused by storm surges or floods could lead to significant damage to marine and fluvial structures. Hydraulic forces add significant hydrodynamic loads on bridges built in coastal and fluvial environments; therefore, the effect of the wave impact on bridge substructures must be properly considered for the safe and cost-effective design of the piers. The use of laboratory-scale models is a direct approach to investigate the effects of long waves on simple structures, mimicking bridge piers. The present study describes a laboratory-scale model, where the propagation of two different long waves in a flume, in the presence …

Approach Flow Depth Influence On Nonlinear Weir Discharge Capacity, Benane Redha, Sebastien Erpicum, Michel Pirotton

International Junior Researcher and Engineer Workshop on Hydraulic Structures

The high hydraulic efficiency and the compactness of nonlinear weirs favor their use in several rehabilitation or new dams projects. Main types of nonlinear weirs are labyrinth and piano key weirs.The purpose of this paper is to provide indications on the influence of the approach flow depth on the discharge capacity of these nonlinear weirs. To do so, a series of experimental tests have been carried out in the laboratory of Engineering Hydraulics of the Liege University. A labyrinth and a piano key weir have been tested in channel configuration (upstream flow width equal to the weir width) considering various …

Discharge Capacity Of A Piano Key Weir With Curvilinear Keys, R. K. Mishra, Z. Ahmad

International Junior Researcher and Engineer Workshop on Hydraulic Structures

The Piano Key Weir (PKW) has emerged as a cost effective and viable solution for dam rehabilitation and new projects with high level of space constraints. The geometrical dimensions of PKW are main factors affecting their discharging capacity. Since, it is a relatively new type of weir that has only been developed in recent years, the description of the effect of its geometrical parameters is still immature. The geometric designs of these weirs presented in the literatures incorporate only linear floor slope of the keys. For better understanding of the influence of curvilinear shapes of outlet key slopes on discharge …

Development Of A 1 Kw Gravitational Water Vortex Hydropower Plant Prototype, A. Sapkota, A. Gautam, A. B. Timilsina, S. Dhakal, S. R. Shakya, T. R. Bajracharya

International Junior Researcher and Engineer Workshop on Hydraulic Structures

A pilot testing of a Gravitational Water Vortex Hydropower Plant (GWVHP) has been done to evaluate the applicability in a real-world scenario and validate the results from the lab-scale model. A scaled-up model of a capacity of 1 kW was constructed for the evaluation purpose. The test provided data in good agreement with a lab-scale model and a proper visualization to install Gravitational Water Vortex in real-world scenarios. The project lasted for nearly four months and thus provided important information on the problems that might arise in scaling up the lab model to a micro-hydro system. The pilot testing shows …

Differing Effects Of Four Building Materials On Viable Bacterial Communities And Vocs, Gwynne Á. Mhuireach, Leslie Dietz, Willem Griffiths, Patrick Finn Horve, Aurélie Laguerre, Dale Northcutt, Roo Vandegrift, Elliott T. Gall, Kevin Van Den Wymelenberg

Mechanical and Materials Engineering Faculty Publications and Presentations

Indoor environmental quality is a paramount concern among architects. Exposure to VOCs and microorganisms impacts occupant health, yet the role of materials on these exposures remains poorly understood. In this study, we placed four material types in individual microcosms to test whether material type influences bacterial community structure and VOC emission. We used culture-independent methods to characterize bacterial communities and TD-GC-MS to measure VOC emission. We found that viable bacterial communities had different patterns of abundance, diversity, and composition, in comparison with total (viable plus dead cells) bacterial communities. Examining viable bacteria only, Earth had the highest abundance and diversity, …

Microscopic Traffic Simulation As A Decision Support System For Road Diet And Tactical Urbanism Strategies, Bernice Liu, Amirarsalan Mehrara Molan, Anurag Pande, Jonathan Howard, Serena Alexander, Zhiliang Lou

Faculty and Student Publications

Urban street networks in the United States have been primarily designed for automobile traffic with negligible considerations to non-motorized transportation users. Due to environmental issues and quality of life concerns, communities are reclaiming street spaces for active modes and slowing the speeds in their downtown. Moreover, tactical urbanism, i.e., the use of street space for innovative purposes other than moving automobile traffic, is becoming attractive due to reduced automobile travel demand and the need for outdoor activities in the age of the COVID-19 pandemic. This study provides details of the modeling of an urban downtown network (in the City of …

Using Cellular Automata Approach To Optimize The Hydropower Reservoir Operation Of Folsom Dam, Erfan Goharian, Mohammed Azizipour, Samuel Sandoval-Solis, Graham Fogg

Faculty Publications

While hydropower in California is one the main sources of renewable energy, population growth has continuously increased demand for energy. In addition, recent droughts reduced the amount of available water behind the hydropower dams to provide the water head needed to run the turbines in hydropower plants. A more sustainable alternative, instead of developing new infrastructure, is to enhance the daily operation of reservoirs to support hydropower generation. This study suggests a new optimal operation policy for Folsom Reservoir in California and hydropower plants, which maximizes hydropower generation and reduces flood risk. This study demonstrates the application of the cellular …

Biochar Amended Bioretention Systems For Nutrient And Fecal Indicator Bacteria Removal From Urban And Agricultural Runoffs, Md Yeasir Arif Rahman

USF Tampa Graduate Theses and Dissertations

Excessive nitrogen and fecal indicator bacteria (FIB) in stormwater runoff from urban areas or dairy farm operations impair water bodies resulting algal blooms, gastrointestinal illness, and economic losses. Recent advancements in stormwater management, including low impact development (LID) techniques, have provided engineers with a variety of tools to use in place of traditional catch basins and retention ponds. One promising LID technology for runoff management is bioretention, which consists of a shallow depression containing engineered porous media and vegetation. Prior studies have shown that modified bioretention systems that include an internal water storage zone (IWSZ) to promote denitrification can improve …

Review Of Expansive And Collapsible Soil Volume Change Models Within A Unified Elastoplastic Framework, Sandra L. Houston, Xiong Zhang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Numerous laboratory tests on unsaturated soils revealed complex volume-change response to reduction of soil suction, resulting in early development of state surface approaches that incorporate soil expansion or collapse due to wetting under load. Nonetheless, expansive and collapsible soils are often viewed separately in research and practice, resulting in development of numerous constitutive models specific to the direction of volume change resulting from suction decrease. In addition, several elastoplastic models, developed primarily for collapse or expansion, are modified by add-on, such as multiple yield curves/ surfaces, to accommodate a broader range of soil response. Current tendency to think of unsaturated …

How To Resolve Channel Travel Time Errors In The Tr-55 Worksheet Using Arc Hydro Tools, Hec-Geohms And Hec-Hms, Philip A. Adalikwu, Suzette R. Burckhard

Civil and Environmental Engineering Reports and Manuals

This tutorial is an illustration of a stepwise procedure for resolving errors in calculated channel travel times that occur when processing watershed parameters in HEC-GeoHMS. Channel travel time errors occur when a GIS-defined channel slope value during preprocessing of the Digital Elevation Data (DEM) is zero or negative (Adalikwu, 2021). The tutorial is intended to assist a relatively experienced ArcMap user resolve channel travel time errors that are documented in the TR55 Worksheet. Particularly, this tutorial is useful if the Muskingum method is selected by the watershed modeler as the river routing method. The K parameter value in the Muskingum …

Achieving Domestic Internationalization And Global Competence Through On-Campus Activities And Globally Responsive Education, Sanjay Tewari, Peng Zhang, Yuan Zhuang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The impacts of the COVID-19 pandemic on students and educators are well known. However, there is a paucity of literature available on its impact on educational institutions in the context of their abilities to develop global competence in the middle of an ongoing pandemic. The virtual communication and remote delivery of educational content have been a popular trend for many universities to adapt to the pandemic challenges and re-think their internationalization strategies.

The limited travel opportunities because of the pandemic have highlighted a big need for the domestic internationalization mechanism at educational institutions. In this paper, the authors discuss how …

Towards Smallholder Food And Water Security: Climate Variability In The Context Of Multiple Livelihood Hazards In Nicaragua, Christopher M. Bacon, William A. Sundstrom, Iris Stewart-Frey, Edwin P. Maurer, Lisa C. Kelley

Environmental Studies and Sciences

Climate variability and change affect both food and water security, as do other hazards, such as shifting food prices, plant pathogens, and political economic changes. Although household food and water insecurity affect billions, most studies analyze them separately. This article develops a relational approach to explaining household access to food and water in a multi-hazard context. We identify pathways linking hazards to livelihood vulnerability and assess the relative importance of climate-related hazards. Analyzing longitudinal data collected from two surveys of the same 311 smallholder households in northern Nicaragua, conducted in 2014 and again in 2017, we find that peak seasons …

The Environmental Benefits Of Implementing Green Roofs On City Skyscrapers, Jack Rich

Civil Engineering Student Work

No abstract provided.

Frequency Effect On Peak Pressure Coefficients Using The Narrowband Synthesis Random Flow Generator (Nsrfg) Method, Zayuris Del Carmen Atencio Mojica

Graduate Theses and Dissertations

The collapse of the Tacoma Narrows Bridge in Washington state in 1940 due to high wind forces gave structural engineers notice of the importance of understanding the behavior of wind forces on infrastructure. Wind forces play an important role in the design of buildings and other structures. ASCE 7-16 is the manual used for the design of these buildings and other structures throughout the country. These design criteria have been approved based on research projects involving experimental procedures. For the design of wind loads, ASCE 7-16 uses criteria based on wind tunnel (WT) tests. However, since the development of computing …

Applications Of Masw And Mhvsr Techniques For Infrastructure Evaluation With A Focus On The Effects Of Different Transformation Techniques And Near-Field Effects On Derived Dispersion Data, Salman Rahimi

Graduate Theses and Dissertations

This dissertation is aimed at understanding two aspects of active surface wave methods to improve the accuracy and reliability of this method. These include (1) the performance of four common wavefield transformation methods for the multichannel analysis of surface wave (MASW) data processing and (2) near-field effects. Toward this end, extensive field measurements were conducted considering different factors affecting these two topics. The MASW and microtremor horizontal to vertical spectral ratio (MHVSR) were then employed to examine their efficiency for infrastructure health monitoring.

Regarding the performance of the four common transformation techniques, it was observed that for sites with a …

Data-Driven Methods To Address Truck Parking Shortages For Long-Haul Commercial Truck Drivers, Sharif Mahmud

Graduate Theses and Dissertations

Truck parking is a critical concern for both the trucking industry and the truck drivers. Long-haul commercial truck drivers rely on safe and adequate parking to support interstate commerce, which has become a challenge due to parking shortages. The recent electronic logging device (ELD) mandate, forcing a strict compliance to hours of service (HOS) regulations, are leading to higher demand for parking. A number of federal, regional, and local studies reveal that truck activity will increase and truck parking demand will outpace parking supply in the coming years. Such parking shortages likely disrupt freight flows and pose risks to truck …

Mitigating Calcium Oxychloride Damage In Cementitious Paste And Concrete Utilizing Supplementary Cementitious Materials, Casey Jones

Graduate Theses and Dissertations

It is understood among engineers in the United States (U.S.) that improvement is needed throughout the transportation infrastructure. In the 2021 Infrastructure Report Card produced by the American Society of Civil Engineers, the roadways of this nation merit a D. This leaves room for improvement in order to provide durable pavements throughout this nation. Areas with significant winter weather may have exacerbated effects in decreased roadway longevity due to freezing/thawing cycles and the use of chemical deicers to mitigate gelid roadway conditions. Much research focuses on surface scaling and reinforcement corrosion using these materials; however, joint deterioration, due to chemical …

Random Packing Material In Disinfection Contactors: Effects On Baffling And Energy Loss, Jessica L. Baker, Subhas K. Venayagamoorthy, Susan K. De Long

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study investigates the potential improvement in the hydraulic disinfection efficiency and the possible energy loss as a result of the presence of random packing material (RPM) in a laboratory-scale chlorine contactor. Tracer tests were conducted on a 55-gal drum tank filled with RPM in varying amounts in different configurations to measure the efficiency of each setup in terms of baffling factor (BF). The bulk pressure drop was measured to determine the energy loss for each configuration. The results of this study show that securing RPM near the inlet, in any amount, improves the BF by 300% to more than …