Research -
Submerged Vane Induced Lateral Bedload Transport in Reservoir Sedimentation
(2022- 2024)
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In river engineering, in-stream structures are used to control flow and sediment movement to prevent erosion, intake clogging, and habitat disruption. Submerged vanes are small, angled structures that are installed to redirect sediments toward a preferred direction by creating secondary flow circulations. This research experimentally tests an array of porous vanes in an open channel to measure and quantify the lateral displacement of sediment. Porous plates were selected to minimize local scour and anchoring requirements while directing flow, bedforms, and sediment laterally. The proposed vane array is part of a modular hydro suction sediment bypass system being developed for low-head dams, which features inlets to collect coarse sediments and siphon them over the dam via a slurry conduit. The vane array is meant to be installed upstream of the collector to increase the lateral transport of coarse sediment toward the intake structures. Porous elements can potentially be replaced by vegetation and log structures for nature-based alternatives.
The project is funded by the Department of Energy under Award No. DE-EE0008947, led by Dr. Michele Guala at University of Minnesota, and Dr. Mirko Musa at Oak Ridge National Laboratory (now at EPFL in Switzerland).
Related Publications:
Hydrokinetic Energy applications within Hydropower Tailrace Channels
(2022 - 2024)
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Hydropower tailrace channels are unique and attractive locations for hydrokinetic energy harvesting due to fast currents, scheduled flow releases, proximity to existing structural and electrical infrastructures, and low risk of additional environmental impacts. However, energy-extracting devices create flow resistance, inducing a small but measurable water level increase, which may diminish the available hydraulic head and reduce hydropower generation, defeating the initial value proposition.
This project proposed a one-dimensional momentum balance approach, combining with the backwater equation for surface-varying open channel flow to analyze the water level increase and determine the optimal turbine siting distance that maximizes the net power production (balancing hydropower loss vs. hydrokinetic gain). Using a subset of sites from the U.S. hydropower fleet, we provided a high-level estimation of the hydrokinetic potential available in tailraces in the United States. This project advocated for the adoption of hydrokinetic turbines downstream of dams as an opportunity to increase energy production at existing plants and Non-Powered Dams (NPDs) with minimal structural intervention and, alternatively, as viable sites for large-scale field testing for hydrokinetic devices.
The project is funded by the US Department of Energy’s Water Power Technologies Office (WPTO), led by Dr. Mirko Musa at Oak Ridge National Laboratory (now at EPFL in Switzerland).
Related Publications:
Advanced Manufacturing and Hydraulic Testing for Hydropower Innovations
(2022 - 2024)
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Hydropower has been a significant contributor to global clean and renewable energy for over a century. Despite advancements in technology and design, the manufacturing of hydropower components still relies on traditional methods. Recent changes in global energy production and supply chain challenges are encouraging the industry to rethink its processes. The hydropower sector faces challenges such as maintenance issues and environmental impacts, while innovation in new technologies and modernization of facilities offers opportunities for advanced manufacturing. In the U.S., future developments will focus on low-head sites (less than 10 meters), primarily through retrofitting existing plants. However, small hydropower facility owners often lack the risk-bearing capacity to adopt new technologies, which hinders growth. To foster innovation, systematic validation activities are needed. Full-scale testing of low-head turbines and environmental mitigations, potentially using decommissioned infrastructure, could reduce risks and support the international expansion of hydropower.
This research project supports the U.S. Department of Energy’s (DOE) Water Power Technologies Office (WPTO) by examining and analyzing the current and emerging manufacturing challenges in U.S. hydropower. The goal is to identify high-impact opportunities in advanced manufacturing methods (AMM) and highlight the necessity for full-scale testing to address these challenges effectively.
The project is funded by the US Department of Energy’s Water Power Technologies Office (WPTO), led by Dr. Mirko Musa at Oak Ridge National Laboratory (now at EPFL in Switzerland).
Related Publications:
Turbulence-induced Sediment Suspension in Vegetated Flows
(2017 - 2022)
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Aquatic vegetation serves important roles in wetlands, estuaries, riverine, and coastal areas. It provides shelter for living organisms, protects coastal and riverbank regions from waves, currents, and floods, and makes a contribution to global carbon circulation. However, under various scenarios of environmental change, the presence of aquatic vegetation continuously decreased in these areas during recent decades. To improve restoration efforts and protect vegetation habitats, understanding vegetation-sediment dynamics is paramount and will lead to more accurate models of landscape evolution and water quality management.
Traditional suspended sediment models, widely applied in open-channel flows, do not work in regions with aquatic plants. In this project, we proposed a modified model to predict suspended sediment concentration in vegetated flows, validated with experimental data. The new model showed that near-bed turbulence generated by bed-vegetation-flow interaction is as important as bed- and vegetation-generated turbulence, which is considered separately. The model is expected to provide critical information for future studies on sediment transport, landscape evolution, and water quality management in vegetated streams, wetlands, and estuaries.
The project is funded by NSF Career (EAR 1753200), led by Dr. Rafael Tinoco at University of Illinois at Urbana-Champaign.
Related Publications:
Turbulence-induced Interfacial Gas Transfer in Vegetated Flows
(2017 - 2022)
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Turbulence generated by aquatic vegetation plays an important role in interfacial transfer processes across the air-water and sediment-water interface, which impacts the dissolved oxygen level, a key indicator of water quality. This project aims to investigate the influence of vegetation under different submergence ratios and plant densities on gas transfer mechanisms. Laboratory experiments were designed and conducted with simulated rigid vegetation on a sediment bed. Surface gas transfer rates and sediment-water transfer fluxes were measured by monitoring the dissolved oxygen level. Our experiment results and the proposed models provide critical information for predictions and future studies on water quality management and ecosystem restoration in natural water environments such as lakes, rivers, and wetlands.
The project is funded by NSF Career (EAR 1753200), led by Dr. Rafael Tinoco at University of Illinois at Urbana-Champaign.
Related Publications:
Multi-fidelity Uncertainty Quantification of Hydraulic Conductivity in a Watershed
(2019 - 2021)
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Enhanced water management systems depend on the accurate estimation of hydraulic properties of subsurface formations. This is while the hydraulic conductivity of geologic formations could vary significantly. Therefore, using information only from widely spaced boreholes will be insufficient in characterizing subsurface aquifer properties. Hence, there is a need for other sources of information to complement our hydrogeophysics understanding of a region of interest.
This project presents a numerical framework where information from different measurement sources is combined to characterize the 3-dimensional random field representing the hydraulic conductivity in Upper Sangamon Watershed in east-central Illinois under a Multi-Fidelity (MF) estimation model. Coupled with this model, a Bayesian experimental design will also be presented and used to select the best future sampling locations. This work draws upon the unique capabilities of electrical resistivity tests as well as statistical inversion.
The project is funded by Illinois Water Resources Center, led by Dr. Maryam Ghadiri and Dr. Hadi Meidani at University of Illinois at Urbana-Champaign.
Development of the Portable Thermal Response Testing (TRT) System
(2018 - 2019)
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The thermal response test (TRT) is widely applied to determine geothermal properties, such as geothermal conductivity and geothermal resistance. The TRT works on the principle that the mean temperature change caused by heated circulating water can be measured through the ground over time. The temperature response is due to heat transfer from the heated inflow to the borehole heat exchanger. This temperature response can provide us with an extrapolated prediction of the geothermal performance.
In this project, we designed a portable TRT device with a technical report describing a comprehensive workflow for operating it based on model analysis theory. We illustrated a test case of TRT measurement at the Geothermal Research Station located at the University of Illinois Energy Farm. The purpose of the report is to help future users of the TRT device learn to use the device to conduct a basic analysis of raw data from shallow geothermal heat exchange-related projects and to apply this test in both scientific research and educational programs.
The project is funded by the Geothermal Profile Project from Illinois State Geological Survey, led by Dr. Yu-Feng Forrest Lin at University of Illinois at Urbana-Champaign.
Related Publications:
Non-hydrostatic Coastal Ocean Modeling of Hyperpycnal River Plumes
(2013 - 2016)
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Hyperpycnal plume is a kind of sediment-laden current moving down a slope in water, which is driven by gravity and frequently occurs in nature such as lakes, reservoirs and estuaries. It plays an important role in sediment transport and carbon circulation in nature. However, it can also cause some environmental and industrial problems. Owing to the aforementioned significance, a further understanding about the mechanisms of hyperpycnal plume is required.
By using the coastal hydrodynamic ocean model "SUNTANS", we investigated the nonhydrostatic effect and the dynamics of hyperpycnal plumes on different slopes. The result showed that the nonhydrostatic effect is important in the plunging region, which can be closely related to the change of slope and 3D flow structure.
The project was funded by Taiwan Ministry of Science and Technology (MOST) Civil, Hydraulic Engineering Program under Grant No. 103-2221-E-002-206-MY3 and Aeronautical Engineering Program under Grant No. 102-2221-E-002-069-MY3, led by Dr. Yi-Ju Chou at National Taiwan University.
