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Articles 121 - 150 of 198

Full-Text Articles in Civil Engineering

The Effect Of Multi-Model Averaging Of Climate Model Outputs On The Seasonality Of Rainfall Over The Columbia River Basin, Mehmet Demirel, Arun Rana, Hamid Moradkhani Sep 2014

The Effect Of Multi-Model Averaging Of Climate Model Outputs On The Seasonality Of Rainfall Over The Columbia River Basin, Mehmet Demirel, Arun Rana, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

The rainfall seasonality index is the measure of precipitation distribution throughout the seasonal cycle. The aim of this study is to compare the effect of different multi-model averaging methods on the rainfall seasonality index at each 1/16 latitude-longitude cells covering the Columbia River Basin. In accordance with the same, ten different climate model outputs are selected from 45 available climate models from CMIP5 dataset. The reanalysis precipitation data is used to estimate the errors in rainfall seasonality for the climate model outputs. The inverse variance method and statistical multi criteria analysis (SMCA) method were used to estimate the weights for …


Can Tidal Perturbations Associated With Sea Level Variations In The Western Pacific Ocean Be Used To Understand Future Effects Of Tidal Evolution?, Adam T. Devlin, David A. Jay, Stefan A. Talke, Edward D. Zaron Aug 2014

Can Tidal Perturbations Associated With Sea Level Variations In The Western Pacific Ocean Be Used To Understand Future Effects Of Tidal Evolution?, Adam T. Devlin, David A. Jay, Stefan A. Talke, Edward D. Zaron

Civil and Environmental Engineering Faculty Publications and Presentations

This study examines connections between mean sea level (MSL) variability and diurnal and semidiurnal tidal constituent variations at 17 open-ocean and 9 continental shelf tide gauges in the western tropical Pacific Ocean, a region showing anomalous rise in MSL over the last 20 years and strong interannual variability. Detrended MSL fluctuations are correlated with detrended tidal amplitude and phase fluctuations, defined as tidal anomaly trends (TATs), to quantify the response of tidal properties to MSL variation. About 20 significant amplitude and phase TATs are found for each of the two strongest tidal constituents, K1 (diurnal) and M2 (semidiurnal). …


Modeling And Analyzing The Impact Of Advanced Technologies On Transit Performance Measures In Arterial Corridors, Miguel A. Figliozzi, Wei Feng Aug 2014

Modeling And Analyzing The Impact Of Advanced Technologies On Transit Performance Measures In Arterial Corridors, Miguel A. Figliozzi, Wei Feng

Civil and Environmental Engineering Faculty Publications and Presentations

Transportation and transit agencies have implemented advanced technologies like transit signal priority (TSP) and Sydney Coordinated Adaptive Traffic System (SCATS) to reduce travel times and improve reliability. However, due to the lack of detailed empirical data, the joint impact of these factors and improvement strategies on bus travel time has not been studied at the stop-to-stop segment level. With the aim of assessing the performance of an existing TSP/SCATS system, this study had access to a unique set of high-resolution bus and traffic signal data. Novel algorithms and performance measures to measure TSP performance are proposed. Results indicate that a …


An Analysis Of Secular Change In Tides At Open-Ocean Sites In The Pacific, Edward D. Zaron, David A. Jay Jul 2014

An Analysis Of Secular Change In Tides At Open-Ocean Sites In The Pacific, Edward D. Zaron, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Hourly sea level is examined at 25 open-ocean stations in the Pacific Ocean with records longer than 30 yr. A search for trends finds that the amplitude of the dominant semidiurnal tide M2 is increasing at 12 of the 13 sites where a statistically significant trend can be identified. It is also found that nontidal variance in the neighborhood of M2 is decreasing at all 12 of the sites where a significant increase in M2 tide is occurring. The trend in amplitude of the dominant diurnal tide K1 is significant at six stations, and it is …


Lessons From The Green Lanes: Evaluating Protected Bike Lanes In The U.S., Christopher Monsere, Jennifer Dill, Nathan Mcneil, Kelly J. Clifton, Nick Foster, Tara Goddard, Mathew Berkow, Joe Gilpin, Kim Voros, Drusilla Van Hengel, Jamie Parks Jun 2014

Lessons From The Green Lanes: Evaluating Protected Bike Lanes In The U.S., Christopher Monsere, Jennifer Dill, Nathan Mcneil, Kelly J. Clifton, Nick Foster, Tara Goddard, Mathew Berkow, Joe Gilpin, Kim Voros, Drusilla Van Hengel, Jamie Parks

Civil and Environmental Engineering Faculty Publications and Presentations

This report presents finding from research evaluating U.S. protected bicycle lanes (cycle tracks) in terms of their use, perception, benefits, and impacts. This research examines protected bicycle lanes in five cities: Austin, TX; Chicago, IL; Portland, OR; San Francisco, CA; and Washington, D.C., using video, surveys of intercepted bicyclists and nearby residents, and count data. A total of 168 hours were analyzed in this report where 16,393 bicyclists and 19,724 turning and merging vehicles were observed. These data were analyzed to assess actual behavior of bicyclists and motor vehicle drivers to determine how well each user type understands the design …


Time-Variable Refraction Of The Internal Tide At The Hawaiian Ridge, Edward D. Zaron, Gary D. Egbert Feb 2014

Time-Variable Refraction Of The Internal Tide At The Hawaiian Ridge, Edward D. Zaron, Gary D. Egbert

Civil and Environmental Engineering Faculty Publications and Presentations

The interaction of the dominant semidiurnal M2 internal tide with the large-scale subtidal flow is examined in an ocean model by propagating the tide through an ensemble of background fields in a domain centered on the Hawaiian Ridge. The background fields are taken from the Simple Ocean Data Assimilation (SODA) ocean analysis, at 2-month intervals from 1992 through 2001. Tides are computed with the Primitive Equation Z-coordinate Harmonic Analysis of Tides (PEZ-HAT) model by 14-day integrations using SODA initial conditions and M2 tidal forcing. Variability of the tide is found to occur primarily as the result of propagation through …


Making Bridges Outlast Rising Waters, Daniel Cox Jan 2014

Making Bridges Outlast Rising Waters, Daniel Cox

TREC Project Briefs

During Hurricanes Ivan in 2004 and Katrina in 2005, at least 11 highway and railroad bridges along the U.S. Gulf Coast were damaged by wave forces. The spans of these bridges typically rested on bent column supports, and were attached to the supports by a variety of connection methods. Failure of these connections caused bridge spans to be washed away when the water rose high enough to lift them off. To build bridges that can withstand such forces, engineers must be able to estimate the effects the forces will have.

Investigator Daniel Cox of Oregon State University has conducted wave …


A Comparative Assessment Of Crowded Source Travel Time Estimates: A Case Study Of Bluetooth Vs Inrix On A Suburban Arterial, Fahad Fasha Alhajri Jan 2014

A Comparative Assessment Of Crowded Source Travel Time Estimates: A Case Study Of Bluetooth Vs Inrix On A Suburban Arterial, Fahad Fasha Alhajri

Civil and Environmental Engineering Master's Project Reports

Travel time is one of the most widely used measures of traffic performance monitoring for the transportation systems. It is a simple concept that refers to the time required to traverse between two points of interest. Travel time is communicated and used by a wide variety of audience such as commuters, media reporters, and transportation engineers and planners. Recent developments within the wireless communication area made it possible to collect travel time data at a relatively low cost. These emerging technologies include mobile phone based technologies, in-vehicle navigation technologies and automatic vehicle identification technologies. Although these technologies offer a great …


Testing And Strengthening Bridge Connections, Christopher Higgins, Peter Dusicka, Michael Scott Jan 2014

Testing And Strengthening Bridge Connections, Christopher Higgins, Peter Dusicka, Michael Scott

TREC Project Briefs

Researchers evaluate and improve the strength of gusset plate connections, essential pieces in bridge design that can fail due to buckling.


Evaluation Of Truck Signal Priority At N Columbia Blvd And Martin Luther King Jr. Blvd Intersection: Vissim Micro Simulation Analysis Of Truck Signal Priority, Maisha Mahmud Jan 2014

Evaluation Of Truck Signal Priority At N Columbia Blvd And Martin Luther King Jr. Blvd Intersection: Vissim Micro Simulation Analysis Of Truck Signal Priority, Maisha Mahmud

Civil and Environmental Engineering Master's Project Reports

Given the importance of over growing freight transportation system worldwide, engineers and planners are faced with the challenge of improving freight service in urban area using low cost measure. Truck Signal Priority is one of the strategy that can be used to improve operational efficiency with enhance safety benefits (red light running) of freight service, without major capital investment. In light to this interest this study focus on evaluating the impacts of freight signal priority on a high truck density intersection like N Columbia Blvd and NE Martin Luther King Jr. Blvd. Using a simulation tool, VISSIM, these impacts were …


Wider Dissemination Of Household Travel Survey Data Using Geographical Perturbation Methods, Kelly J. Clifton, Steven R. Gehrke Jan 2014

Wider Dissemination Of Household Travel Survey Data Using Geographical Perturbation Methods, Kelly J. Clifton, Steven R. Gehrke

Civil and Environmental Engineering Faculty Publications and Presentations

Public agencies spend vast amounts of money collecting information about passenger travel in household travel surveys. These data are valuable for the rich and detailed information they provide, which contribute to regional and statewide travel demand models. These data have utility beyond travel demand modeling in their application to transportation policy and travel behavior research. As the demand on these data increase, so have the quantity of information collected. Detailed geospatial referencing of the home, work and other travel destinations are common practice and permit the integration with other spatially archived data sources, such as land use characteristics, transportation system …


Turbulent Kinetic Energy And Coherent Structures In A Tidal River, Stefan A. Talke, Alexander R. Horner-Devine, C. Chris Chickadel, Andrew T. Jessup Dec 2013

Turbulent Kinetic Energy And Coherent Structures In A Tidal River, Stefan A. Talke, Alexander R. Horner-Devine, C. Chris Chickadel, Andrew T. Jessup

Civil and Environmental Engineering Faculty Publications and Presentations

We investigate the relationship between turbulence statistics and coherent structures (CS) in an unstratified reach of the Snohomish River estuary using in situ velocity measurements and surface infrared (IR) imaging. Sequential IR images are used to estimate surface flow characteristics via a particle-image-velocimetry (PIV) technique, and are conditionally sampled to delineate the surface statistics of bottom-generated CS, or boils. In the water column, we find that turbulent kinetic energy (TKE) production exceeds dissipation near the bed but is less than dissipation in the midwater column and that TKE flux divergence closes a significant portion of the measured imbalance. The surface …


Research Project Work Plan For Impact Of Cascadia Subduction Zone Earthquake On The Seismic Evaluation Criteria Of Bridges, Peter Dusicka Dec 2013

Research Project Work Plan For Impact Of Cascadia Subduction Zone Earthquake On The Seismic Evaluation Criteria Of Bridges, Peter Dusicka

Civil and Environmental Engineering Faculty Publications and Presentations

The goal of this project is to provide ODOT with the best rational estimate of ground acceleration values for designing new and retrofitting existing bridges. The objectives are to:

  • evaluate the hazard by contrasting the acceleration values from individual CSZ events to PSHA values
  • provide experimental evidence of damage difference under longer duration shaking expected from CSZ event


The Effect Of The Bicycle Detector Symbol And R10-22 Sign On Cyclist Queuing Position At Signalized Intersections, Stefan W. Bussey Oct 2013

The Effect Of The Bicycle Detector Symbol And R10-22 Sign On Cyclist Queuing Position At Signalized Intersections, Stefan W. Bussey

Civil and Environmental Engineering Undergraduate Honors Theses

The Manual of Traffic Control Devices (MUTCD) includes a roadway marking and accompanying explanatory sign which may be installed on public roads to help guide cyclists position themselves over detection at actuated traffic signals. While adopted into the MUTCD in 2003, little research is available on the effectiveness of the marking and sign. This study evaluates the influence that the roadway marking, roadway marking installed in conjunction with the explanatory sign, and an alternative detector marking comprised of the MUTCD marking installed over a one foot by two feet green rectangle, have on cyclist queuing position at actuated, signalized intersections. …


Understanding Travel Modes To Non-Work Destinations: Analysis Of An Establishment Survey In Portland, Oregon, Christopher D. Muhs Jun 2013

Understanding Travel Modes To Non-Work Destinations: Analysis Of An Establishment Survey In Portland, Oregon, Christopher D. Muhs

Dissertations and Theses

During the past three decades, research in travel behavior has generally proceeded from broad-level, aggregate analysis of mode share--the proportions of walking, bicycling, transit, and vehicle travel occurring in traffic analysis zones, census tracts, neighborhood, or other geographical units--to fine-grained, disaggregate analysis of mode choices and other trip-making attributes at the individual level. One potential issue is whether there are differences in the types of conclusions drawn from results of analyses performed at these different levels, as these results directly inform transportation planning and policy.

This thesis aims in part to confirm whether the types of conclusions drawn from different …


Predicting Landslides In Real Time, Michael J. Olsen Mar 2013

Predicting Landslides In Real Time, Michael J. Olsen

TREC Project Briefs

The Oregon Department of Transportation, or ODOT, has an ongoing struggle to maintain public highways against earth movements such as erosion, earthquakes and landslides. An earthquake or landslide can close down a road for days, while highway workers fight to keep supply lines open and repair the damage. Particularly along Oregon’s coastal roads with high sea cliffs, these natural processes are a constant threat to transportation infrastructure. The damage caused by gradual erosion is typically not detectable until there is a landslide or other disaster, costing the state considerable time and money to repair. New technology has the potential to …


Protecting Bridges From Earthquake Damage, Peter Dusicka Mar 2013

Protecting Bridges From Earthquake Damage, Peter Dusicka

TREC Project Briefs

Earthquake damage to bridges can have serious effects on a transportation network. When a bridge is out, the damage can go well beyond what is immediately visible: in addition to the cost of repairing it, the state must deal with short-term and long-term interruptions to traffic. These interruptions can delay repair and construction, as well as impacting post earthquake emergency response and causing the loss of valuable time for commuters and freight. To prevent this situation, older bridges (ones that are past an average construction life of about 50 years) should be retrofitted with stronger materials, especially in earthquake- prone …


Adaptation Of Classical Tidal Harmonic Analysis To Nonstationary Tides, With Application To River Tides, Pascal Matte, David A. Jay, Edward D. Zaron Mar 2013

Adaptation Of Classical Tidal Harmonic Analysis To Nonstationary Tides, With Application To River Tides, Pascal Matte, David A. Jay, Edward D. Zaron

Civil and Environmental Engineering Faculty Publications and Presentations

One of the most challenging areas in tidal analysis is the study of nonstationary signals with a tidal component, as they confront both current analysis methods and dynamical understanding. A new analysis tool has been developed, NS_TIDE, adapted to the study of nonstationary signals, in this case, river tides. It builds the nonstationary forcing directly into the tidal basis functions. It is implemented by modification of T_TIDE; however, certain concepts, particularly the meaning of a constituent and the Rayleigh criterion, are redefined to account for the smearing effects on the tidal spectral lines by nontidal energy. An error estimation procedure …


Examining Consumer Behavior And Travel Choices, Kelly J. Clifton, Christopher Devlin Muhs, Sara Morrissey, Tomás Morrissey, Kristina Marie Currans, Chloe Ritter Feb 2013

Examining Consumer Behavior And Travel Choices, Kelly J. Clifton, Christopher Devlin Muhs, Sara Morrissey, Tomás Morrissey, Kristina Marie Currans, Chloe Ritter

Civil and Environmental Engineering Faculty Publications and Presentations

This study represents a first attempt to answer a few of the questions that have arisen concerning multimodal transportation investments and the impacts of mode shifts on the business community. This research aims to merge the long history of scholarly work that examines the impacts of the built environment on non-work travel with the relatively new interest in consumer spending by mode of travel. This empirical study of travel choices and consumer spending across 89 businesses in the Portland metropolitan area shows there are important differences between the amounts customers spend on average at various businesses by their mode of …


Experimental Tests And Numerical Analyses Of Steel Truss Bridge Gusset Connections, Christopher Higgins, Peter Dusicka, Michael Scott Nov 2012

Experimental Tests And Numerical Analyses Of Steel Truss Bridge Gusset Connections, Christopher Higgins, Peter Dusicka, Michael Scott

TREC Final Reports

The collapse of the I-35W Bridge in Minneapolis, Minnesota has raised questions regarding the performance and possibly safety of steel truss bridges. The failure investigation indicated that the collapse was due to a design error in the gusset plates used to connect the truss members. The findings also recommend that evaluation of truss connections will be needed, which is a deviation from past practice where only members were considered. Gusset plates connect individual steel truss bridge members together at a node. In 10% of the 200,000 steel bridges in US in 2008, failure of a single truss or connection could …


Operational Guidance For Bicycle-Specific Traffic Signals In The United States, Christopher Monsere, Miguel A. Figliozzi, Sam Thompson, Kirk Paulsen Aug 2012

Operational Guidance For Bicycle-Specific Traffic Signals In The United States, Christopher Monsere, Miguel A. Figliozzi, Sam Thompson, Kirk Paulsen

Civil and Environmental Engineering Faculty Publications and Presentations

The research consisted of two phases: 1) a synthesis of practice and 2) and analysis of cyclist performance characteristics. The synthesis of current practice reviewed the literature, current engineering design and operational guidance documents, and surveyed the jurisdictions about their current deployments of bicyclespecific signals. This report summarizes research of cyclist behavior at signalized intersections in Portland, Eugene, Corvallis, Beaverton and Clackamas County, OR. These signals had both bicycle-specific indications and vehicle-only signals. A total of 4,673cyclists were observed. For each cyclist observed arriving on red, a set of descriptive variables were collected (e.g., age, sex, helmet use, presence of …


Laboratory Performance Of Highway Bridge Girder Anchorages Under Simulated Hurricane-Induced Wave Loading, Jora Lehrman, Christopher Higgins, Daniel Cox Jul 2012

Laboratory Performance Of Highway Bridge Girder Anchorages Under Simulated Hurricane-Induced Wave Loading, Jora Lehrman, Christopher Higgins, Daniel Cox

TREC Final Reports

Many bridges along the Gulf Coast of the United States were damaged by recent hurricanes, and many more are susceptible to similar damage. This research examines the structural performance of common connection details used to anchor prestressed concrete girders to the substructure. Full-scale specimens were fabricated and tested under static and dynamic cyclic load histories. Dynamic load histories were developed from previously conducted hydraulic tests of a 1/5 scale model of a highway bridge under hurricane wave loads. The load effects considered included the pseudo-statically applied vertical uplift force, horizontal force, combined horizontal and vertical forces, and dynamically applied combined …


Seismic Hazard Assessment Of Oregon Highway Truck Routes, Peter Dusicka, Selamawit Tesfayesus Mehary Jun 2012

Seismic Hazard Assessment Of Oregon Highway Truck Routes, Peter Dusicka, Selamawit Tesfayesus Mehary

TREC Final Reports

This research project developed a seismic risk assessment model along the major truck routes in Oregon. The study had adopted federally developed software tools called Risk for Earthquake Damage to Roadway Systems (REDARS2) and HAZUS-MH. The model was the first time REDARS2 has been adopted and used in research outside of the original development team, presenting a number of unique challenges. The development of the model was a complex, intensive process that required a significant research effort, manipulation and adjustment of data. Furthermore, limitations of the software tools themselves had been identified that prevented the inclusion of important aspects such …


Real-Time Change And Damage Detection Of Landslides And Other Earth Movements Threatening Public Infrastructure, Michael J. Olsen, Shawn Butcher, Evon P. Silvia Mar 2012

Real-Time Change And Damage Detection Of Landslides And Other Earth Movements Threatening Public Infrastructure, Michael J. Olsen, Shawn Butcher, Evon P. Silvia

TREC Final Reports

Geologic hazards such as coastal erosion, landslides, seismic loading, etc. constantly threaten public highway construction and maintenance. Repeat surveys using terrestrial laser scanning (TLS, ground-based LiDAR) enable rapid 3D data acquisition to map, see, analyze, and understand the processes generating such problems. Previously, change detection and analysis between scan surveys was conducted during post-processing upon return to the office, instead of while collecting data in the field. Change detection in the field improves the effectiveness and efficiency of the field investigation. We have developed a new algorithm that quickly geo-references scans upon field acquisition and simultaneously performs change detection by …


Strength And Fatigue Of Three Glass Fiber Reinforced Composite Bridge Decks With Mechanical Deck To Stringer Connections, Andrew Gleason, Peter Dusicka Feb 2012

Strength And Fatigue Of Three Glass Fiber Reinforced Composite Bridge Decks With Mechanical Deck To Stringer Connections, Andrew Gleason, Peter Dusicka

Civil and Environmental Engineering Faculty Publications and Presentations

Replacement of the steel grating deck on the lift span of the Morrison Bridge in Portland, OR, will utilize glass fiber reinforced polymer (FRP) panels to address ongoing maintenance issues of the deteriorated existing deck, improve driver safety and introduce bridge water runoff treatment. This report outlines the testing methods and results of an experimental program aimed primarily at evaluating a new open cell deck. While most FRP panels are connected via shear studs that are grouted within isolated pockets, the panels in this case were bolted directly to the steel stringers. Two different FRP deck options were evaluated for …


Refining Greenstep: Impacts Of Vehicle Technologies And Its/Operational Improvements On Travel Speed And Fuel Consumption Curves, Kelly Clifton, Alexander Y. Bigazzi Nov 2011

Refining Greenstep: Impacts Of Vehicle Technologies And Its/Operational Improvements On Travel Speed And Fuel Consumption Curves, Kelly Clifton, Alexander Y. Bigazzi

Civil and Environmental Engineering Faculty Publications and Presentations

This report describes analysis undertaken to establish a method for incorporating traffic operations and ITS strategies into the GreenSTEP model. We first discuss operations impacts on fuel economy and delay from the literature. Then, an investigation of delay adjustments in GreenSTEP shows that different methods of representing delay changes lead to similar (and small) impacts on fuel economy. From this result we establish average speed adjustment by congestion level as the preferred method for incorporating delay effects from operations improvements. An investigation of aggregate traffic operations impacts produces estimates of base speeds without operations improvements, maximum speeds with full operational …


Evaluation Of Safe Routes To School Programs: Qualitative And Quantitative Analysis Of Parental Decision-Making, Lynn Weigand, Noreen Mcdonald Aug 2011

Evaluation Of Safe Routes To School Programs: Qualitative And Quantitative Analysis Of Parental Decision-Making, Lynn Weigand, Noreen Mcdonald

TREC Final Reports

In the United States, walking to school declined from 42% of 5-18 year olds in 1969 to 16% in 20011. The US Department of Transportation has responded to this dramatic decrease by funding the Safe Routes to School program for $612 million in SAFETEA-LU. The program’s funding emphasize infrastructure improvements such as completing sidewalks and adding crosswalks by requiring between 70% and 90% of funding be allocated toward infrastructure. However, recent research shows that 2 of 3 children who currently are driven to school, but live close enough to walk, do so because it is more convenient for parents. Currently, …


Assessment Of Statewide Intersection Safety Performance, Christopher M. Monsere, Todd Johnson, Karen Dixon, Jianfei Zheng, Ida Schalkwyk Jun 2011

Assessment Of Statewide Intersection Safety Performance, Christopher M. Monsere, Todd Johnson, Karen Dixon, Jianfei Zheng, Ida Schalkwyk

TREC Final Reports

This report summarizes the results of an analysis of the safety performance of Oregon’s intersections. Following a pilot study, a database of 500 intersections randomly sampled from around the state of Oregon in both urban and rural environments was assembled. These intersections were categorized into eight types based on number of legs (3 and 4), land use (urban or rural) and traffic control (signalized or minor stop-control). These categories were chosen to align with the intersection types in AASHTO’s recently released Highway Safety Manual (HSM). Geometric and traffic control elements were supplemented by compiling crash data and volumes on the …


Development Of An Open Source Bridge Management System, Michael H. Scott Feb 2011

Development Of An Open Source Bridge Management System, Michael H. Scott

TREC Final Reports

A bridge management system is developed using the Tcl scripting language in conjunction with the OpenSees finite element software framework. Fully programmable and string-based, Tcl is ideal for implementing live load analysis through scripts and experimenting with emergent bridge rating methodologies. Since Tcl is an interpreted language, the application also has the important advantage that new bridge capacity models and rating factor calculations can be implemented on multiple platforms without compiling source code. The network programming features of Tcl give the system access to databases for conducting internet-based bridge rating. The system is demonstrated for rating a conventionally reinforced concrete …


Infrared-Based Measurements Of Velocity, Turbulent Kinetic Energy, And Dissipation At The Water Surface In A Tidal River, C. Chris Chickadel, Stefan A. Talke, Alexander R. Horner-Devine, Andrew T. Jessup Jan 2011

Infrared-Based Measurements Of Velocity, Turbulent Kinetic Energy, And Dissipation At The Water Surface In A Tidal River, C. Chris Chickadel, Stefan A. Talke, Alexander R. Horner-Devine, Andrew T. Jessup

Civil and Environmental Engineering Faculty Publications and Presentations

Thermal infrared (IR) based particle image velocimetry (PIV) is used to measure the evolution of velocity, turbulent kinetic energy (TKE), and the TKE dissipation rate at the water surface in the tidally influenced Snohomish River. Patterns of temperature variability in the IR imagery arise from disruption of the cool skin layer and are used to estimate the 2D velocity field. Comparisons of IR based PIV mean velocity made against a collocated acoustic velocimeter demonstrate high correlation (r2 > 0.9). Over a tidal period, surface TKE computed from the IR velocity varies from 10-4 J·kg-1 to 3x10-3 J·kg-1, with an average difference …