Engineering Commons^™

World Register Of Piano Key Weirs, Sebastien Erpicum, Tohid Jamali Rovesht, Brian M. Crookston, Pierre Archambeau

4th International Workshop on Labyrinth and Piano Key Weirs

Piano Key Weirs have been proposed in 2003. Since then, more than 40 projects have been commissioned over the world. This presentation details a world register of piano key weir prototypes, freely available online. It also analyses the main characteristics of these structures in operation to highlight trends in design.

Value Added 3d Modeling – Lower Crow Dam Spillway Modification And Rehabilitation Project, Justin Bartels

4th International Workshop on Labyrinth and Piano Key Weirs

The Confederated Salish and Kootenai Tribes (CSKT) have been operating Lower Crow Dam under restricted reservoir levels since 2008 due to significant structural and spillway capacity deficiencies that have increased risk to dam safety. Stantec was contracted by the CSKT to evaluate rehabilitation options and provide final design for the new spillway. The focus of this paper is to describe the design methodology and spillway selection process with an emphasis on the hydraulic modeling completed to support the final spillway arrangement. The design approach included the evaluation of various spillway types including gated, Obermeyer, fuse gate, ogee, labyrinth, and piano …

Design Approach For Labyrinth Weir: Case Study Of La Laye Dam, M. Roy, S. Derrien, J. Schaguene, G. Dautois

4th International Workshop on Labyrinth and Piano Key Weirs

This paper presents ARTELIA’s gradual approach for the design and construction of labyrinth weirs, from the preliminary concept design to the commissioning. It is illustrated with the case of La Laye dam, where an additional lateral spillway with labyrinth weir has been developed to increase the existing discharge capacity. The design process involved preliminary hydraulic calculations, 3D numerical modeling and a physical scale model. The paper elaborates on the technical solutions and optimizations which were considered to provide the Client with the most hydro-economical solution.

Advances In Arced Labyrinth Weir Research And Application At The Springton Spillway Project, Seth Thompson, Blake Tullis, Brian M. Crookston

4th International Workshop on Labyrinth and Piano Key Weirs

Arced labyrinth weirs, characterized by a curved cycle orientation, can enhance discharge efficiency compared to linear labyrinth weirs by taking advantage of the approaching flow field in reservoirs. This paper summarizes some of the Utah State University arced labyrinth weir hydraulic efficiency research findings, including sidewall and cycle arc angle influences, nappe aeration, and local submergence. Recent CFD modeling that replicates some of the experimental findings is also highlighted, demonstrating CFD utility for design. The Springton Spillway project, owned by Aqua Pennsylvania, leveraged this research when designing a two-stage, eight-cycle arced labyrinth weir to replace an aging ogee crest spillway …

Piano Key Weir With Orifice Sluice, Dau Xuan Thuy

4th International Workshop on Labyrinth and Piano Key Weirs

In recent years, many Piano Key Weirs (PKW) have been built around the world. In Vietnam there are more than 18 PKWs in operation to the present. However, during the operation, some experience has been drawn on the design and application conditions. This paper is about the Dak Mi 3 reservoir with a PKW that operated well for more than 4 years until an exceptional flood following typhoons in October 2020, making reservoir fully filled with mud and sand. The result is the PKW became ineffective and the hydropower plant unable to operate. In order to dredge the reservoir and …

Honey, I Shrunk The Pk Weir: A Case Study Of Burton Pond Dam, David Bisio

4th International Workshop on Labyrinth and Piano Key Weirs

Between a low-head tidal environment, razor-thin hydraulic margins, and a long list of site restrictions, the Burton Pond Dam Rehabilitation project offered the chance to pursue a one-of-a-kind solution: a miniature stainless steel piano key weir as part of a new mixed active-passive spillway. This case study will explore how established hydraulic designs were modified specifically for the site and verified with computational flow dynamics; how the innovative cantilevered geometry was analyzed structurally with finite element modeling; and how detailing, fabrication and constructability were considered throughout the design process. From conceptual-level design submissions to the final construction walkthrough, the whole …

Research And Application Of Piano Key Weirs In Vietnam (2025), M. Ho Ta Khanh, Dau Xuan Thuy

4th International Workshop on Labyrinth and Piano Key Weirs

Since the Piano Key Weirs (PKW) were introduced by F. Lempérière and A. Ouamane (2003) many such structures have been built for irrigation, hydroelectricity and water regulation due to their outstanding efficiency. In Vietnam, PKWs have also attracted significant attention. There have been several laboratory hydraulic model studies to test the discharge capacity, flow characteristics, and energy dissipation downstream the spillway. Vietnam had also issued PKW design standard for easy of application in 2018. This paper describes shortly 18 Piano Key Weirs in operation in Vietnam (among other existing PKWs) : Dak Mi 4B, Dak Mi 3, Dak Rong 3, …

Lessons Learned From The Hydraulic Design Of The Prado Dam Labyrinth Spillway, Yajayra Diaz, Mike Phillips, Brian M. Crookston, Julie D. Allen

4th International Workshop on Labyrinth and Piano Key Weirs

The U.S. Army Corps of Engineers has completed the design of a new labyrinth weir spillway at Prado Dam, in southern California. The proposed labyrinth weir would consist of an arced configuration, 7-cycles, with varying weir wall height from 28 ft to 41 ft with upstream head over the weir cycles of up to 30 ft. This paper highlights the key lessons learned from the hydraulic design of the new labyrinth weir, including significant fluctuating negative pressures at the weir wall resulting in hydrodynamic loads that should be considered during structural design and submergence of the weir at high heads.

Synthetically Expressive: Evaluating Gesture And Voice For Emotion And Empathy In Vr And 2d Scenarios, Haoyang Du, Kiran Chhatre, Christopher Peters, Brian Keegan, Rachel Mcdonnell, Cathy Ennis

Conference papers

The creation of virtual humans increasingly leverages automated synthesis of speech and gestures, enabling expressive, adaptable agents that effectively engage users. However, the independent development of voice and gesture generation technologies, alongside the growing popularity of virtual reality (VR), presents significant questions about the integration of these signals and their ability to convey emotional detail in immersive environments. In this paper, we evaluate the influence of real and synthetic gestures and speech, alongside varying levels of immersion (VR vs. 2D displays) and emotional contexts (positive, neutral, negative) on user perceptions. We investigate how immersion affects the perceived match between gestures …

Investigation Of Flow Field Near A Type-A Piano Key Weir, S. Hussain, M. S. Quamar, Z. Ahmad

4th International Workshop on Labyrinth and Piano Key Weirs

Piano Key Weirs (PKWs) enhance spillway capacity and induce complex flow patterns around their inlet and outlet keys. This study investigates the flow near a Type-A PKW using Computational Fluid Dynamics (CFD). Velocity fields in the vicinity of the PKW keys were analyzed for different discharges and validated with the experimental results. As flow approaches the inlet key, the streamwise, vertical, and lateral velocity components increase significantly, with the highest velocities near the inlet key. However, near the outlet key the streamwise velocity decreases while the vertical and lateral components increase. For all the discharges, the maximum velocity was observed …

Key Width Ratio Influence On Discharge Coefficients Of Trapezoidal Piano Key Weirs Via Openfoam Simulations, Lisa Lüddecke, Mario Oertel

4th International Workshop on Labyrinth and Piano Key Weirs

Piano key weirs are characterized by complex three-dimensional flow structures with multiple parameters describing their geometry. The variation of these parameters can affect several flow characteristics such as efficiency, energy dissipation and air entrainment. Identifying the optimal geometry for enhanced hydraulic performance represents a significant challenge. Physical or numerical modeling of multiple geometric variants is necessary to identify the relevant optimal parameters. The key width ratio (between an inlet and an outlet key) represents one of the parameters that influences the hydraulic behavior of the piano key weir. In particular, it affects the discharge coefficient, which in turn affects the …

Experimental And Numerical Investigation Of A-Type Rectangular Side Piano Key Weir, Sabir Hussain, Zulfequar Ahmad

4th International Workshop on Labyrinth and Piano Key Weirs

A side weir is a structure installed along the side wall of a channel, serving multiple purposes, such as raising water levels for irrigation and drainage and diverting excess flow from rivers or channels during floods. Most studies have focused so far on linear rectangular and labyrinth side weirs, with relatively limited research conducted on side Piano key weirs. In this paper, an experimental and numerical simulation was performed on an A-type rectangular side piano key weir and a rectangular sharp-crested side weir. The diversion discharge of Piano key side weirs was within the range of ± 10% with numerical …

Sensitivity Analysis Of Piano-Key Weirs Design: Optimizing Discharge Performance Through Cfd Modeling And Empirical Insights, Fatna Oukaili, Yvan Bercovitz, Thomas Fonty, Benoit Blancher, Julien Vermeulen

4th International Workshop on Labyrinth and Piano Key Weirs

Piano-key weirs (PKWs) are widely recognized for their efficiency in enhancing spillway discharge capacity while maintaining a compact footprint. This study focuses on a parametric and sensitivity analysis of PKW discharge performance, exploring the influence of key design parameters on hydraulic behavior. By integrating experimental data with advanced computational fluid dynamics (CFD) modeling using the open-source code_saturne software, we aim to refine predictive capabilities and establish guidelines for effective PKW design. The analysis emphasizes understanding the interplay between PKW geometry and flow characteristics. The analysis considers a range of geometrical configurations, including variations in key width ratios, and inlet-to-outlet dimensions, …

An Innovative Use Of Piano Key Weirs Or Labyrinth Weirs For Long Dams In Plains, Michel Ho Ta Khanh

4th International Workshop on Labyrinth and Piano Key Weirs

Piano Key Weirs (PKW) are labyrinth type weirs but with upstream and/or downstream overhangs which allow them to have a reduced footprint at their base. The new solution of a combination of gates and PKW (or labyrinth weir) for a long dams has many advantages of costs for investment, operation and safety during high floods. If a new dam is built on a broad river where a large footprint is possible, the choice between a PKW and a labyrinth weir can arise as the difference of specific discharges of the two alternatives are relatively small and the construction of the …

An Innovative Association Of Fusegate And Pk-Weir, F. Lempérière, A. Chapuis, F. Del Rey, C. Bessière

4th International Workshop on Labyrinth and Piano Key Weirs

The combination on the same dam of Piano Key weir (PK-Weir) and fusible structures offers a highly effective passive solution for managing flood discharges. This concept first introduced by Hydrocoop in 2015 as « Innovative Associated Spillways » can leverage the strength of each system. More than 30 years after its first application, the returns of experience of the Hydroplus Fusegate® system applications on more than 80 dams in 25 different countries have confirmed their reliability in terms of sequentially overturning on the downstream side for the correct design flood. With their high discharge capacity at low head, PK-Weirs optimize …

Enhancing The Hydraulic Efficiency Of Piano Key Weir (Pkw) — Some Research Achievements, James Yang, Shicheng Li, Anders Ansell, Erik Skepparkrans, Chen Lin

4th International Workshop on Labyrinth and Piano Key Weirs

As an effective flood control structure, the piano key weir (PKW) typically features a rectangular planform for its overhangs. However, this design offers room for improvement. To enhance hydraulic efficiency, two modified PKW layouts are proposed. In the first, the floor of each key is lowered with a semicircular cross-section, forming an elliptical planform and crest. In the second, the floor is lowered with an isosceles triangular prism, creating an equilateral triangular overhang. Both modified PKW models, manufactured by 3D printing, were tested in a large-scale experimental setup. Compared to the reference weir, the elliptical-overhang PKW increases the developed crest …

Theoretical And Experimental Studies Of Non-Rectilinear Weirs -From Labyrinth To Pk-Weir, Ahmed Ouamane, François Lempérière

4th International Workshop on Labyrinth and Piano Key Weirs

Free-flow rectilinear spillways, while simpler and safer than gated or shaft spillways, have a low specific discharge, requiring a significant water head and resulting in a storage loss of more than 20% for some small reservoirs. To overcome this drawback, labyrinth weirs provide an effective alternative, allowing high discharge under a reduced head while maintaining lower construction and maintenance costs. For several decades, global research has focused on optimizing their design. In this context, a research project was initiated in 1995 at the University of Biskra to enhance the understanding of the hydraulic behavior of these structures. This project was …

Physical Model Investigations On Nappe Instabilities At Labyrinth Weirs, Michael Gebhardt, Fabian Belzner

4th International Workshop on Labyrinth and Piano Key Weirs

Free overflow hydraulic structures operating at low heads tend to develop nappe instabilities when there is no ventilation. A detailed investigation has been undertaken with a relatively large-scale labyrinth weir in the hydraulic laboratory of the BAW. A quarter-round crest was selected, because nappe instabilities mainly occur at sharp-crested weirs, which favor the development of an air pocket behind the nappe. The headwater ratios for which nappe instabilities could be observed were determined. Pressure fluctuations were measured and the frequencies determined. Adding splitters to the crest is one way to vent the air pocket and to avoid vibrations. Another possibility …

Model-Prototype Upscaling Of Pkw Discharge Capacity, James Yang, Pär Nilsen, Mats Billstein, L Johnsson, Shicheng Li

4th International Workshop on Labyrinth and Piano Key Weirs

In Sweden, many dams are undergoing upgrades to comply with the revised dam safety guidelines, which mandate higher spillway discharge capacities that their existing ones. As part of an ongoing project, a piano key weir (PKW) is proposed to replace an embankment dam and simultaneously increase the facility’s discharge capacity. The PKW configuration is evaluated in a 2 m wide flume at two geometric scales (1:35 and 1:12) to assess potential scale effects. The former comprises eight units, while the latter includes three, with all components produced using 3D printing. Results indicate that the 1:35 model exhibits a slightly lower …

Interfacial Velocity Characteristics Downstream Of A Piano Key Weir Versus A Linear Weir In A Horizontal Channel, Biruk Belay, Mario Oertel

4th International Workshop on Labyrinth and Piano Key Weirs

The downstream flow characteristics of piano key weirs (PKWs) are highly complex, manifested by significant localized self-aeration due to nape collisions and plunging jets impacting the downstream free-surface. For PKWs installed in horizontal channels, the interfacial velocity characteristics have received limited attention in previous research. In this experimental study, air-water flow measurements were conducted using a double-tip conductivity probe downstream of a PKW and a reference ogee-crested linear weir to evaluate the velocity trends under comparable hydraulic boundary conditions. The findings reveal the existence of two distinct velocity profiles downstream of piano key weirs: quasi-wall-jet and uniform profiles. The occurrence …

Effect Of Driftwood On The Hydraulic Performance Of A-Type Piano Key Weirs Situated In-Stream Or At Reservoirs, Pascal Venetz, Michael Pfister

4th International Workshop on Labyrinth and Piano Key Weirs

Driftwood is a natural part of most river ecosystems. The knowledge of its interaction with hydraulic structures, such as PKWs, is essential for two reasons: To (1) avoid uncontrolled inundations because of the level rise initiated by trapped driftwood (reducing the weir discharge coefficient), and (2) initiate the passage of the wood over the PKW, so that it remains in the river to further fulfill its environmental services. Knowledge of the conditions motivating driftwood to block at a PKW is essential. The present study accordingly focuses on the blocking probability of driftwood at PKWs and the resulting head increase – …

Floating Trees At Co-Existing Pkw & Gated Spillway, James Yang, A. Helgesson, L. Johnsson, Sc Li

4th International Workshop on Labyrinth and Piano Key Weirs

During extreme flood events, floating trees (driftwood) can pose serious risks to the safety and operation of dams. In upgrading an existing dam, a piano key weir (PKW) is introduced to replace the aging embankment dam and to increase the discharge capacity of its gated spillway. This upgrade necessitates a detailed understanding of driftwood behavior at both discharge structures, which differ significantly in design and operating conditions. To investigate this, hydraulic model tests were conducted using small, freshly cut trees—some with branches and roots—to simulate natural trees moving towards the dam. The results indicate that tree accumulation at the gated …

Non-Invasive Way For Detection Of Neonatal Jaundice Using Gbr, Priti V. Bhagat, Mukesh Raghuwanshi, Ashutosh D. Bagde

Chulalongkorn Medical Journal

Background: Neonatal jaundice is a common condition in newborns due to excess levels of bilirubin. The traditional method for bilirubin testing is invasive, i.e., through blood tests only, which is painful to infants. Therefore, this study uses machine learning algorithms to develop a non-invasive way to detect neonatal jaundice.

Objectives: Design a computer-aided support system to detect neonatal jaundice using machine learning algorithm.

Methods: The gradient-boosting regression model is used to predict the bilirubin level. Gradient Boosting is a robust boosting algorithm that combines several weak learners into strong learners, in which each new model is trained to minimize the …

Trustworthy Navigation With Variational Policy In Deep Reinforcement Learning, Karla Bockrath, Liam Ernst, Rohaan Nadeem, Bryan Joseph Pedraza, Dimah Dera

Electrical and Computer Engineering Faculty Publications

Introduction: Developing a reliable and trustworthy navigation policy in deep reinforcement learning (DRL) for mobile robots is extremely challenging, particularly in real-world, highly dynamic environments. Particularly, exploring and navigating unknown environments without prior knowledge, while avoiding obstacles and collisions, is very cumbersome for mobile robots.

Methods: This study introduces a novel trustworthy navigation framework that utilizes variational policy learning to quantify uncertainty in the estimation of the robot’s action, localization, and map representation. Trust-Nav employs the Bayesian variational approximation of the posterior distribution over the policy-based neural network’s parameters. Policy-based and value-based learning are combined to guide the robot’s actions …

Authenticating Electronic Devices Via Multi Tone Analysis, Carl Bohman Jr., Aaron Jennings, Christian Eakins, Mark B. Skouson, Richard Ott, Jamin Mccue

AFIT Patents

Methods and systems for authenticating electronic devices via multi tone analysis. A method for authenticating a device under test (DUT) of a type of DUT includes imparting voltage tones to the DUT. The voltage tones are proximate a frequency of interest that is associated with the type of DUT. Using a measurement response of the DUT to the voltage tones, an electronic signature of the DUT is determined. The DUT is determined to be authentic when the electronic signature of the DUT substantially matches an electronic signature of an authority DUT of the type of DUT.

Control Of Ferroelectric And Dielectric Properties Of Undoped, Fe, And Nb-Doped Single-Crystalline (001) Oriented Pb (Zr0.5ti0.5) O3 Thin Films, Mahamudu H. Mtebwa

Tanzania Journal of Engineering and Technology (TJET)

While several factors that influence the properties of ferroelectric devices have been extensively studied in bulk ceramics and polycrystalline thin films, limited is known about the same on single crystalline thin films which have great potential in memory and energy applications. This knowledge gap is largely due to the limited availability of substrates with lattice parameters suitable for supporting high-quality epitaxial growth. In this study, undoped, Fe-doped, and Nb-doped (001)-oriented Pb(Zr₀.₅Ti₀.₅)O₃ thin films were deposited using pulsed laser deposition, each with a SrRuO₃ bottom electrode and a PrScO₃ substrate. The doping concentration used is 1% for both Fe and Nb. …

Maximum Likelihood Symbol Timing Algorithm Based On Cyclic Prefix For Ofdm Systems, Kwame S. Ibwe

Tanzania Journal of Engineering and Technology (TJET)

In this paper, a blind symbol synchronization algorithm is presented for orthogonal frequency-division multiplexing (OFDM) systems, and a timing function based on the redundancy of the cyclic prefix (CP) is introduced. The existing algorithms rely on the prior knowledge of the channel energy distribution i.e. channel power profile. In practical environment the channel power profile is unknown to the receiver and its statistics are expected to be highly changing. Nevertheless, the use of pilot symbols in channel profile estimation reduces efficiency as data subcarriers are used to carry pilots instead of payload. In this paper a timing function that accounts …

Condition Optimization For The Synthesis Of Castor Oil Templated Mesoporous Silica, Godlisten Namwel Shao

Tanzania Journal of Engineering and Technology (TJET)

The present work provides suitable conditions for the synthesis of mesoporous materials with improved porosity using an optimization technique. The proposed preparation method involves forming final products by varying the amount of castor oil, media, and template removal. The obtained samples were examined by TGA, XRD, DRIFT and nitrogen physisorption studies. It was observed that the porosity of the obtained samples was dependent on the conditions under which the materials were synthesized. All synthesized materials showed the Type IV adsorption-desorption isotherm features of mesoporous, regardless of the conditions utilized during the synthesis. The sample synthesized using 2.5 g of a …

Techno-Economic Analysis Of Hybrid Pv-Wind-Diesel Generator Swarm Grid For Rural Electrification In Tanzania, Ibrahim Mwammenywa

Tanzania Journal of Engineering and Technology (TJET)

Remote, rural, and off-grid communities, particularly in Sub-Saharan Africa (SSA), face significant challenges in securing reliable and affordable electricity. While solutions such as solar home systems (SHSs) and diesel generators (DGs) have been adopted by some individuals, their deployment is often not optimized to meet the full load demand. This study addresses this challenge by proposing a hybrid swarm grid (HSG) design that integrates photovoltaic (PV), wind energy, and diesel generators (DGs). Utilizing MATLAB/Simulink and HOMER, the HSG is modeled and optimized for a typical SSA village, incorporating real-world variables such as load demand profiles, solar irradiance, and wind patterns. …

Adoption Of Agrivoltaics In Developing Countries: A Review On Challenges, Opportunities And Future Prospects, Abdi J. Athumani, Pater Makolo

Tanzania Journal of Engineering and Technology (TJET)

This paper provides a review of agrivoltaics technology and how it has been applicable in developing countries, including African countries. Agrivoltaics, the integration of agricultural production with photovoltaic energy generation, offers promising solutions to water- energy-food nexus in developing countries. This technology offers the dual benefit of increasing agricultural productivity while generating clean energy, which is very important for regions facing frequent electricity shortages and declining agricultural yields due to climate change. However, despite its potential, the adoption of agrivoltaics in developing nations remains limited in comparison to developed countries due to financial, technical and policy constraints. This paper explores …