Decelerating Open Channel Flow Over Gravel: Turbulence Structure & Sensor Development
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University of Kentucky UKnowledge Theses and Dissertations--Civil Engineering Civil Engineering 2014 DECELERATING OPEN CHANNEL FLOW OVER GRAVEL: TURBULENCE STRUCTURE & SENSOR DEVELOPMENT Robert L. Stewart III University of Kentucky, [email protected] Right click to open a feedback form in a new tab to let us know how this document benefits ou.y Recommended Citation Stewart, Robert L. III, "DECELERATING OPEN CHANNEL FLOW OVER GRAVEL: TURBULENCE STRUCTURE & SENSOR DEVELOPMENT" (2014). Theses and Dissertations--Civil Engineering. 25. https://uknowledge.uky.edu/ce_etds/25 This Doctoral Dissertation is brought to you for free and open access by the Civil Engineering at UKnowledge. It has been accepted for inclusion in Theses and Dissertations--Civil Engineering by an authorized administrator of UKnowledge. For more information, please contact [email protected]. STUDENT AGREEMENT: I represent that my thesis or dissertation and abstract are my original work. Proper attribution has been given to all outside sources. I understand that I am solely responsible for obtaining any needed copyright permissions. I have obtained needed written permission statement(s) from the owner(s) of each third-party copyrighted matter to be included in my work, allowing electronic distribution (if such use is not permitted by the fair use doctrine) which will be submitted to UKnowledge as Additional File. I hereby grant to The University of Kentucky and its agents the irrevocable, non-exclusive, and royalty-free license to archive and make accessible my work in whole or in part in all forms of media, now or hereafter known. I agree that the document mentioned above may be made available immediately for worldwide access unless an embargo applies. I retain all other ownership rights to the copyright of my work. I also retain the right to use in future works (such as articles or books) all or part of my work. I understand that I am free to register the copyright to my work. REVIEW, APPROVAL AND ACCEPTANCE The document mentioned above has been reviewed and accepted by the student’s advisor, on behalf of the advisory committee, and by the Director of Graduate Studies (DGS), on behalf of the program; we verify that this is the final, approved version of the student’s thesis including all changes required by the advisory committee. The undersigned agree to abide by the statements above. Robert L. Stewart III, Student Dr. James F. Fox, Major Professor Dr. Yi-Tin Wang, Director of Graduate Studies DECELERATING OPEN CHANNEL FLOW OVER GRAVEL: TURBULENCE STRUCTURE & SENSOR DEVELOPMENT ___________________________________ DISSERTATION ___________________________________ A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the College of Engineering at the University of Kentucky By Robert Lynn Stewart III Lexington, Kentucky Director: Dr. James F. Fox, Professor of Civil Engineering Lexington, Kentucky 2014 Copyright © Robert Lynn Stewart III 2014 ABSTRACT OF DISSERTATION DECELERATING OPEN CHANNEL FLOW OVER GRAVEL: TURBULENCE STRUCTURE & SENSOR DEVELOPMENT This dissertation describes investigations of fully turbulent decelerating hydraulically roughbed flow over gravel and the development of technology to measure turbulence and associated sediment transport in streams. Theory is developed for predicting velocity distributions in simple uniform flow using the asymptotic invariance principle and tested using laboratory and field collected data. A mixed scale is developed that accounts for bed derived turbulent structures throughout the flows depth and is used to parameterize the external boundary’s effect on the flow for the logarithmic and outer layers. The asymptotic invariance principle and similarity analysis is conducted for the equations of motion in the outer region of decelerating flow over gravel to define equilibrium conditions for this class of flows with the velocity scale is the freestream velocity. The combination of time series and time averaged statistical analysis of turbulent flow is used to elucidate the structure of flow under decelerating conditions. Time averaged statistical measures of turbulence confirm results of others for higher Froude number approaching transcritical and time series analysis shows the effects of decelerating flow on turbulence to be frequency dependent. Wireless velocity sensors were developed and found capable of measuring time averaged velocity and able to resolve macroturbulence from time series data. A semi- theoretical model of elastic deformation of cantilever beams under hydraulic forcing was coupled with circuit theory to develop a calibration procedure for the VBS that requires only three measurement points, one of which is at zero velocity. Light based sensors are developed to estimate light attenuation in water for ecological research or estimating sediment concentration in water. A semi-theoretical scaling of light attenuation and sediment properties was developed which predicts light attenuation from sediment properties. The combination of new theory on open channel velocity, turbulent structure and field sensors for measuring turbulence and sediment offers the possibility to extend our laboratory knowledge to realistic flow situations. Key words: Nonuniform flow, Channel, Macrtoturbulence, Sensors, Light Attenuation Robert Lynn Stewart III ___________ . 8-27-2014 . NONUNIFORM OPEN CHANNEL FLOW OVER GRAVEL: TURBULENCE STRUCTURE & SENSOR DEVELOPMENT By Robert Lynn Stewart III Dr. James F Fox . Director of Dissertation Dr. Yi-Tin Wang . Director of Graduate Studies 08-27-2014 . Date ACKNOWLEDGEMENTS This work benefited greatly from contributions of my Dissertation committee, fellow graduate students, faculty, and technical staff from departments and laboratories. First and foremost, I’d like to thank my dissertation advisor, Dr. Jimmy Fox for everything. Specifically for enabling me to be better able to understand, test, and communicate nonuniform open channel hydraulics and associated processes. The opportunity to study under your guidance has truly been a blessing. I’d like to thank members of my dissertation committee: Dr. Yi-Tin Wang, Dr. Scott Yost, Dr. Johnathon Phillips and my outside examiner Dr. Donald Colliver, for encouraging me along the way, providing me with opportunities, stimulating my interest for science, testing my abilities, and for your time and interest in my education and future endeavors. Further, I’d like to thank the numerous graduate and undergraduate researchers that aided with sample collection and processing, Dr. Harnett for her hard work and assistance with sensor fabrication and design as well as technical support. I want to thank Drs. Sean Bailey and Carmen Agouridis for use of laboratory equipment. I have a special appreciation for the numerous graduate and undergraduate students for help with experimental design and data collection, there are too many to name them all but I would specifically like to think Dr. Bill Ford. Additionally I would like to thank Sheila, Suzy, and Mrs. Betty for helping me navigate the collegiate network. I would like to thank by family friends and neighbors for their support, especially my parents and Micki and Chuck who were always there for me through the rollercoaster ride known as graduate school. A special thanks to my parents for supporting me in any venture that made me happy, including graduate school. Finally, I’d like to thank the College of Engineering, U.S. Geological Society, the National Science Foundation, and the Kentucky Science and Engineering Foundation for providing financial support for my graduate studies and data collection. iii TABLE OF CONTENTS Acknowledgements ......................................................................................................... iii Table of Contents ............................................................................................................ iv List of Tables .................................................................................................................. vii List of Figures ................................................................................................................. viii Chapter 1: Introduction .................................................................................................. 1 1.1 Summary ............................................................................................................... 1 1.2 References ............................................................................................................. 3 Chapter 2: Mixed Scaling for Open-Channel Flow over Gravel and Cobbles .............. 5 2.1 Summary ............................................................................................................... 5 2.2 Introduction ........................................................................................................... 5 2.3 Similarity Analysis ............................................................................................... 7 2.4 Data Comparison and Statistical Analysis ............................................................ 11 2.5 Integral Analysis ................................................................................................... 13 2.6 Discussion ............................................................................................................. 14 2.7 Conclusions ..........................................................................................................