Saint Anthony Falls Laboratory | |
Location | Minneapolis, Minnesota |
---|---|
Built | 1938 |
Engineer | Lorenz G. Straub [1] |
Part of | St. Anthony Falls Historic District (ID71000438) |
The Saint Anthony Falls Laboratory (former name: Saint Anthony Falls Hydraulic Laboratory), or SAFL, is a research laboratory situated on Hennepin Island in the Mississippi River in Minneapolis, Minnesota, United States. Its primary research is in "Engineering, Environmental, Biological, and Geophysical Fluid Mechanics". [2] It is affiliated with the University of Minnesota's College of Science and Engineering. Research is conducted by graduate students and faculty alike using the 16,000 square feet of research space and 24 different specialized facilities.
The laboratory is unique in that its location next to Saint Anthony Falls allows it to use the hydraulic head from the waterfall to provide water for many of the experiments.
The experiments performed at the laboratory are varied, and may include:
The Saint Anthony Falls Laboratory is also the headquarters of the National Center for Earth-surface Dynamics, a National Science Foundation Science and Technology Center. [3]
The laboratory is a contributing resource of the Saint Anthony Falls Historic District which is listed on the National Register of Historic Places. [4]
SAFL was designed and built in the 1930s with funding provided by the Works Progress Administration and was headed by Lorenz G. Straub until his death in 1963. Construction began in March, 1936 and the Lab was opened and dedicated in November, 1938.
At first, SAFL focused on hydraulic and engineering research, but after Straub's death the Lab began to expand its research to broader focuses such as stratified flows, turbulence and hydrology. An atmospheric layer wind tunnel and multiple flumes were also added to the collection of research facilities. This was made possible through funding from the National Science Foundation (NSF).
From 1977 through 1993, the Laboratory emphasized the integration of education and basic and applied research. Several new faculty were appointed to bring new research efforts to SAFL like computational fluid dynamics, water resources and energy, environmental water research, naval hydrodynamics, cavitation, wind engineering, small hydropower development, rainfall modeling, and geomorphology to name a few. The NSF made SAFL the headquarters of the National Center of Earth-Surface Dynamics (NCED) in 2002, a center devoted to greater predictive earth surface technology and research.
In 2006, the University of Minnesota and St. Anthony Falls Laboratory implemented a wind-energy research consortium, called EOLOS, which brought together academic partners, industry, and government laboratories with help of a grant from the Department of Energy. This new facility located just south of Minneapolis brought SAFL more into the world of renewable energy research with the addition of a wind turbine among other things.
Since then, SAFL has become an internationally renown leader in the study of earth surface and fluid dynamics. Multiple new facilities have been added over the years to expand research capabilities and many have actually been created by the staff and are exclusively used by SAFL researchers.
Funding for SAFL's expansions has come throughout the years from a number of outside sources like NASA, NSF, U.S. Navy, Department of Energy, Air Force Office of Scientific Research, Hamburg Ship Model Basin, the Legislative-Citizen Commission for Minnesota Resources, and many more.
The St. Anthony Falls Laboratory was added as a research facility to the University of Minnesota's College of Science and Engineering in 2011.
Research at SAFL includes the work of many fields, including civil engineering, hydraulic engineering, hydrology, ecology, and geology. Research at SAFL has been spurred on in the first decade of the 21st century by its status as the headquarters of the National Center for Earth-surface Dynamics (NCED)
Analog material models of fluvial and depositional systems are employed by geologists at SAFL to understand the causes of river channel morphologies and dynamics, as well as to reconstruct the history of events that produces particular stratigraphic packages. Researchers working on channel morphology have shown the importance of vegetation in restricting braided channels to a single thread (and often sinuous) system. [5] [6] Research done on experimental alluvial fan deltas has highlighted the statistics of flow occupation and their potential hazard to life and property, [7] shown autogenic cyclicity in patterns of sediment storage and release that determine short-term shoreline positions, [8] and has been connected to sequence stratigraphy and the processes that form the stratigraphic record. [8] [9] [10] [11] [12] [13]
Research at SAFL is primarily concentrated in four major areas:
SAFL became involved with NCED in 2002, an NSF Science and Technology center that focuses on developing an integrated, quantitative approach to predicting the evolution of Earth's surface. It concentrates on a full range of critical disciplines such as engineering, Earth science, biology, mathematics, physics, and social sciences. Now SAFL is a part of NCED2, a grant that supports the continuation of the research synthesis postdoctoral and outreach programs created by NCED.
At present, SAFL's Earth surface research revolves around the following interlinked themes:
SAFL's long-term research vision is to "develop an interconnected system of theoretical and computational models, supported by data streams from the living surface environment, that can provide testable, adaptive predictions for scenarios ranging from environmental restoration and natural hazard mitigation to changes in precipitation to global sea-level rise." [14]
SAFL has active research programs in a number of areas to assess and quantify global change impacts and to develop science-based solutions for mitigating their consequences such as an altered atmosphere and a degradation of water resources.
SAFL research areas include:
"Mitigating the impacts of global environmental change will be at the forefront of scientific research for many decades to come. SAFL is positioned to help create real and measurable impacts through catalyzing large-scale interdisciplinary research, integrating engineering with social, behavioral, and economic sciences, leveraging big data and data-driven science, exploiting exponentially growing computational capacity, and actively engaging stakeholders, policy makers, and communities." [14]
Since 2007 SAFL has developed new experimental facilities at laboratory and field scales, advanced computational tools, and new partnerships with industry and government laboratories to position itself for more capable research in fluid mechanics and renewable energy systems. This research focus aims to use research and technology to combat and study the effects of climate change such as more frequent extreme weather phenomena, and sea level rise.
SAFL research in this field includes:
"The most economically feasible strategies for significantly reducing global carbon emissions involve substantial increases in energy production from renewable resources, which presently contribute only 10-13% in the world’s energy portfolio... Renewable energy technologies based on wind energy, marine hydrokinetic energy, and biofuel energy are integral parts of the living Earth-surface environment. The implementation of these technologies should be supported by mechanistic models, which are driven by real-time data, and should be integrated with policy, economics, human health sciences, and ecology. SAFL can provide national leadership on all of these fronts, working with a mindset to actively engage industry, government and state agencies, and other renewable energy stakeholders." [14]
The coupling between fluid mechanics and biology has led to growth in recent years of research aimed at understanding the fluid mechanics of the human body and quantifying their linkages with disease pathways.
SAFL is a leader in cardiovascular fluid mechanics research using a simulation-based research approach. Novel computational hemodynamics tools have been developed, validated, and applied to study a wide range of clinically relevant problems. Partnerships have been established and leveraged within the UMN with the Department of Biomedical Engineering, the Department of Aerospace Engineering and Mechanics, the Medical School, and the Institute for Engineering in Medicine, as well as with the Mayo Clinic and other collaborators around the country.
Research themes include:
The guiding task for biomedical fluid mechanics research in the coming years is integration of computational tools from the academic research arena to clinical practice supporting the rapidly emerging future of personalized health care.
The St. Anthony Falls Laboratory is a 16,000 square foot research facility on the Mississippi River. The Lab has 15 general purpose flumes, tanks, and channels that are readily configurable to the needs of a project and can indefinitely pump in water from the Mississippi at up to 300 ft³/s. Facilities at SAFL include the main channel, through which Mississippi River water can be sent for large-scale sediment transport experiments; the delta basins, designed to quickly build experimental stratigraphy; the eXperimental EarthScape facility (XES, nicknamed "Jurassic Tank"), a subsiding basin for large-scale depositional modeling; the Outdoor Stream Lab, which is used to understand fluvial processes and riparian ecology at closer to a field scale; and many other pieces of equipment. The lab is known for rapidly constructing and destructing experimental apparatuses, including full-scale models of rivers to understand the effects of dam removal.
The main channel is SAFL's largest research channel, measuring 275 feet in length, is a straight, concrete channel that has the capability of a 300 ft³/s flow rate of water from the Mississippi River that can be run as a pond system or a flow-through system. The channel is equipped with a wave generator, sediment flux monitoring and recirculation system, and a data acquisition carriage.
This specialized basin is used to study delta and basin morphodynamics on geologic time scales. This basin is unique to SAFL because of its design and capabilities: it can incorporate the effects of tectonism on surface processes by simulating subsidence in the basin floor and its data carriage allows data collection over the entire XES basin and assists in "slicing" for more visible cross-sections. The XES basin is home to SAFL's most advanced data carriage.
These two rectangular basins part of SAFL research on deltas and deltaic systems. The basins allow control of water surface, sediment feed, and water feed rates. Data acquisition includes a new SAFL-designed data carriage, topographic scanner, and various camera systems. Both basins are 16.4 x 16.4 feet and are 2.1 feet deep.
Located outside of the SAFL building, this uniquely designed outdoor field-scale facility was developed by SAFL and NCED and can be used to conduct larger experiments under controlled conditions. It is capable of creating floods and has a large range of flow rates for hydrological, ecological and biological research. the OSL allows for a range of water flow rates, sediment feed rates, a meandering river bend, channel formation, and flooding capabilities. This is used to facilitate a variety of floodplain, vegetation, and channel research opportunities. The StreamLab has a recirculating water outflow of up to a 200 L³/s
Designed for modeling of the air/land boundary layer, the wind tunnel can provide a circulating or once-through flow of air that can reach up to 148 ft/s. It is equipped with a glass observation wall, temperature and surface variation capabilities, a rotating turntable, smoke generator, and laser instrumentation. The tunnel has temperature control capabilities that allow for study effects of thermal stratification in atmosphere on structures.
CloudIA is a SAFL-created facility that is composed of 256 individually controlled air jets that can generate 1 m³ of air turbulence. It is designed to replicate conditions found in the atmosphere to study particle
behavior on a smaller scale. Liquid or solid micro-particles can be dropped in at adjustable rates and are tracked by multiple high-speed cameras and a high-repetition laser. CloudIA is also fully transparent to allow live
visibility.
A wind energy consortium that is partnered with many organizations that range from small companies to government agencies like the U.S. Department of Energy. Ongoing research projects deal with wind farm siting, condition-based monitoring, control system optimization, aeroelastic modeling, drag and noise reduction methods, radar interactions with wind farms, power electronics, and gear boxes.
SAFL also has a number of other specialized research facilities that include multiple flumes, channels, tanks and basins of varying shapes and sizes depending on the research project.
During the academic year, SAFL hosts weekly seminars on various topics related to environmental, geophysical and biological fluid mechanics and engineering featuring presenters from academia, government agencies and industry. These seminars are free and open to the public.
The REU program is a collaboration among the University of Minnesota, the Fond du Lac Band of the Lake Superior Chippewa, and the Confederated Salish and Kootenai tribes in Montana to study various research topics that can help problems in the community. Topics can concentrate on Earth-surface dynamics, geology, civil and environmental engineering, ecology, biology, hydrology, etc.
Erosion is the action of surface processes that removes soil, rock, or dissolved material from one location on the Earth's crust and then transports it to another location where it is deposited. Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as physical or mechanical erosion; this contrasts with chemical erosion, where soil or rock material is removed from an area by dissolution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres.
Geomorphology is the scientific study of the origin and evolution of topographic and bathymetric features generated by physical, chemical or biological processes operating at or near Earth's surface. Geomorphologists seek to understand why landscapes look the way they do, to understand landform and terrain history and dynamics and to predict changes through a combination of field observations, physical experiments and numerical modeling. Geomorphologists work within disciplines such as physical geography, geology, geodesy, engineering geology, archaeology, climatology, and geotechnical engineering. This broad base of interests contributes to many research styles and interests within the field.
A hydraulic jump is a phenomenon in the science of hydraulics which is frequently observed in open channel flow such as rivers and spillways. When liquid at high velocity discharges into a zone of lower velocity, a rather abrupt rise occurs in the liquid surface. The rapidly flowing liquid is abruptly slowed and increases in height, converting some of the flow's initial kinetic energy into an increase in potential energy, with some energy irreversibly lost through turbulence to heat. In an open channel flow, this manifests as the fast flow rapidly slowing and piling up on top of itself similar to how a shockwave forms.
Physical oceanography is the study of physical conditions and physical processes within the ocean, especially the motions and physical properties of ocean waters.
Hydraulic engineering as a sub-discipline of civil engineering is concerned with the flow and conveyance of fluids, principally water and sewage. One feature of these systems is the extensive use of gravity as the motive force to cause the movement of the fluids. This area of civil engineering is intimately related to the design of bridges, dams, channels, canals, and levees, and to both sanitary and environmental engineering.
Fluid mechanics is the branch of physics concerned with the mechanics of fluids and the forces on them. It has applications in a wide range of disciplines, including mechanical, aerospace, civil, chemical, and biomedical engineering, as well as geophysics, oceanography, meteorology, astrophysics, and biology.
A water tunnel is an experimental facility used for testing the hydrodynamic behavior of submerged bodies in flowing water. It functions similar to a recirculating wind tunnel, but uses water as the working fluid, and related phenomena are investigated, such as measuring the forces on scale models of submarines or lift and drag on hydrofoils. Water tunnels are sometimes used in place of wind tunnels to perform measurements because techniques like particle image velocimetry (PIV) are easier to implement in water. For many cases as long as the Reynolds number is equivalent, the results are valid, whether a submerged water vehicle model is tested in air or an aerial vehicle is tested in water. For low Reynolds number flows, tunnels can be made to run oil instead of water. The advantage is that the increased viscosity will allow the flow to be a faster speed for a lower Reynolds number.
Applied mechanics is the branch of science concerned with the motion of any substance that can be experienced or perceived by humans without the help of instruments. In short, when mechanics concepts surpass being theoretical and are applied and executed, general mechanics becomes applied mechanics. It is this stark difference that makes applied mechanics an essential understanding for practical everyday life. It has numerous applications in a wide variety of fields and disciplines, including but not limited to structural engineering, astronomy, oceanography, meteorology, hydraulics, mechanical engineering, aerospace engineering, nanotechnology, structural design, earthquake engineering, fluid dynamics, planetary sciences, and other life sciences. Connecting research between numerous disciplines, applied mechanics plays an important role in both science and engineering.
Marine currents can carry large amounts of water, largely driven by the tides, which are a consequence of the gravitational effects of the planetary motion of the Earth, the Moon and the Sun. Augmented flow velocities can be found where the underwater topography in straits between islands and the mainland or in shallows around headlands plays a major role in enhancing the flow velocities, resulting in appreciable kinetic energy. The Sun acts as the primary driving force, causing winds and temperature differences. Because there are only small fluctuations in current speed and stream location with minimal changes in direction, ocean currents may be suitable locations for deploying energy extraction devices such as turbines. Other effects such as regional differences in temperature and salinity and the Coriolis effect due to the rotation of the earth are also major influences. The kinetic energy of marine currents can be converted in much the same way that a wind turbine extracts energy from the wind, using various types of open-flow rotors.
The College of Science and Engineering (CSE) is one of the colleges of the University of Minnesota in Minneapolis, Minnesota. On July 1, 2010, the college was officially renamed from the Institute of Technology (IT). It was created in 1935 by bringing together the university's programs in engineering, mining, architecture, and chemistry. Today, CSE contains 12 departments and 24 research centers that focus on engineering, the physical sciences, and mathematics.
In fluid dynamics, flow can be decomposed into primary flow plus secondary flow, a relatively weaker flow pattern superimposed on the stronger primary flow pattern. The primary flow is often chosen to be an exact solution to simplified or approximated governing equations, such as potential flow around a wing or geostrophic current or wind on the rotating Earth. In that case, the secondary flow usefully spotlights the effects of complicated real-world terms neglected in those approximated equations. For instance, the consequences of viscosity are spotlighted by secondary flow in the viscous boundary layer, resolving the tea leaf paradox. As another example, if the primary flow is taken to be a balanced flow approximation with net force equated to zero, then the secondary circulation helps spotlight acceleration due to the mild imbalance of forces. A smallness assumption about secondary flow also facilitates linearization.
The National Center for Earth-surface Dynamics, or NCED, is an NSF Science and Technology Center- a collaborative partnership among educational, research, and public/private entities that aims to create new knowledge of significant benefit to society. Its mission is to understand the dynamics of the coupled processes that shape the Earth’s surface—physical, biological, geochemical, and anthropogenic—and how they will respond to climate, land use, and management change. NCED is headquartered at the University of Minnesota's Saint Anthony Falls Laboratory.
The moving particle semi-implicit (MPS) method is a computational method for the simulation of incompressible free surface flows. It is a macroscopic, deterministic particle method developed by Koshizuka and Oka (1996).
In fluid mechanics, the Reynolds number is a dimensionless quantity that helps predict fluid flow patterns in different situations by measuring the ratio between inertial and viscous forces. At low Reynolds numbers, flows tend to be dominated by laminar (sheet-like) flow, while at high Reynolds numbers, flows tend to be turbulent. The turbulence results from differences in the fluid's speed and direction, which may sometimes intersect or even move counter to the overall direction of the flow. These eddy currents begin to churn the flow, using up energy in the process, which for liquids increases the chances of cavitation.
A mouth bar is an element of a deltaic system, which refers to the typically mid-channel deposition of the sediment transported by the river channel at the river mouth.
Subhasish Dey is a hydraulician and educator. He is known for his research on the hydrodynamics and acclaimed for his contributions in developing theories and solution methodologies of various problems on hydrodynamics, turbulence, boundary layer, sediment transport and open channel flow. He is currently a distinguished professor of Indian Institute of Technology Jodhpur (2023–). Before, he worked as a professor of the department of civil engineering, Indian Institute of Technology Kharagpur (1998–2023), where he served as the head of the department during 2013–15 and held the position of Brahmaputra Chair Professor during 2009–14 and 2015. He also held the adjunct professor position in the Physics and Applied Mathematics Unit at Indian Statistical Institute Kolkata during 2014–19. Besides he has been named a distinguished visiting professor at the Tsinghua University in Beijing, China.
Charles Meneveau is a French-Chilean born American fluid dynamicist, known for his work on turbulence, including turbulence modeling and computational fluid dynamics.
Joseph Katz is an Israel-born American fluid dynamicist, known for his work on experimental fluid mechanics, cavitation phenomena and multiphase flow, turbulence, turbomachinery flows and oceanography flows, flow-induced vibrations and noise, and development of optical flow diagnostics techniques, including Particle Image Velocimetry (PIV) and Holographic Particle Image Velocimetry (HPIV). As of 2005, he is the William F. Ward Sr. Distinguished Professor at the Department of Mechanical Engineering of the Whiting School of Engineering at the Johns Hopkins University.
Fotis Sotiropoulos is a Greek-born American engineering professor and university administrator known for his research contributions in computational fluid dynamics for river hydrodynamics, renewable energy, biomedical and biological applications. He currently serves as the Provost and Senior Vice President for Academic Affairs of Virginia Commonwealth University, a position he has held since August 1, 2021
Charles E. Bowers was an American civil engineer, researcher, and educator. He was awarded the Collingwood Prize in 1950 for his study of the Panama Canal.
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