Architectural Engineering Commons^™

Comparisons Of Horizontal-Axis Wind Turbine Wake Interaction Models, Jordan M. Wilson, Cole J. Davis, Subhas K. Venayagamoorthy, Paul R. Heyliger

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, Reynolds-averaged Navier-Stokes (RANS) simulations are performed using the k-ϵ and k-ω shear stress transport (SST) turbulence closure schemes to investigate the interactions of horizontal-axis wind turbine (HAWT) models in the neutrally stratified atmospheric boundary layer (ABL). A comparative study of actuator disk, actuator line, and full rotor models of the National Renewable Energy Laboratory (NREL) 5 MW reference turbine is presented. The open-source computational fluid dynamics (CFD) code open foam 2.1.0 and the commercial software ANSYS fluent 13.0 are used for simulations. Single turbine models are analyzed for turbulent structures and wake resolution in the downstream region. …

The Formation And Fate Of Internal Waves In The South China Sea, Matthew H. Alford, Thomas Peacock, Jennifer A. Mackinnon, Jonathan D. Nash, Maarten C. Buijsman, Luca A. Centurioni, Shenn-Yu Chao, Ming-Huei Chang, David M. Farmer, Oliver B. Fringer, Ke-Hsien Fu, Patrick C. Gallacher, Hans C. Graber, Karl R. Helfrich, Steven M. Jachec, Christopher R. Jackson, Jody M. Klymak, Dong S. Ko, Sen Jan, T. M. Shaun Johnson, Sonya Legg, I-Huan Lee, Ren-Chih Lien, Matthew J. Mercier, James N. Mourn, Ruth Musgrave, Jae-Hun Park, Andrew I. Pickering, Robert Pinkel, Luc Rainville, Steven R. Ramp, Daniel L. Rudnick, Sutanu Sarkar, Alberto Scotti, Harper L. Simmons, Louis C. St. Laurent, Subhas Karan Venayagamoorthy, Yu-Huai Wang, Joe Wang, Ying J. Yang, Theresa Paluszkiewicz, Tswen-Yung David Tang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Internal gravity waves, the subsurface analogue of the familiar surface gravity waves that break on beaches, are ubiquitous in the ocean. Because of their strong vertical and horizontal currents, and the turbulent mixing caused by their breaking, they affect a panoply of ocean processes, such as the supply of nutrients for photosynthesis¹, sediment and pollutant transport² and acoustic transmission³; they also pose hazards for man-made structures in the ocean⁴. Generated primarily by the wind and the tides, internal waves can travel thousands of kilometers from their sources before breaking⁵, making it …

Crack Control Measures For Tilt-Up Concrete Panels, John Lawson

Architectural Engineering

No abstract provided.

2015 Scholarly Productivity Report, Missouri University Of Science And Technology

Civil, Architectural and Environmental Engineering Scholarly Productivity Reports

No abstract provided.

Biases In Thorpe-Scale Estimates Of Turbulence Dissipation. Part I: Assessments From Large-Scale Overturns In Oceanographic Data, Benjamin D. Mater, Subhas K. Venayagamoorthy, Louis St Laurent, James N. Moum

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Oceanic density overturns are commonly used to parameterize the dissipation rate of turbulent kinetic energy. This method assumes a linear scaling between the Thorpe length scale LT and the Ozmidov length scale LO. Historic evidence supporting LTLO has been shown for relatively weak shear-driven turbulence of the thermocline; however, little support for the method exists in regions of turbulence driven by the convective collapse of topographically influenced overturns that are large by open-ocean standards. This study presents a direct comparison of LT and LO, using vertical profiles of temperature and microstructure shear collected in the Luzon Strait-a site characterized by …

Model For Consolidation Analysis Of Layered Soils Under Depth-Dependent Loading, Hefu Pu, Patrick J. Fox

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A numerical model is presented for one-dimensional large strain consolidation of a layered soil stratum. The algorithm accounts for vertical strain, soil self-weight, conventional constitutive relationships, changing material properties during consolidation, unload/reload, time-dependent loading and boundary conditions, an externally applied hydraulic gradient, and multiple soil layers with different material properties. The model can also accommodate depth-dependent loading and variable preconsolidation stress profiles. Verification checks of the model show excellent agreement with available analytical and numerical solutions for consolidation of soils with multiple layers and depth-dependent loading. An overview of this model is presented, and a parametric study is performed to …

Effect Of Fly Ash Replacement Level On The Bond Strength Of Reinforcing Steel In Concrete Beams, Mahdi Arezoumandi, Trevor J. Looney, Jeffery S. Volz

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study compares the bond strength of reinforcing steel in high-volume fly ash concrete (HVFAC) mixes. Three mixes with 0% (conventional concrete), 50%, and 70% replacement of Portland cement with a Class C fly ash investigated in this study. Three beams (simply supported four-point loading condition) as well as three pull-out specimens (based on RILEM recommendations) were tested for each mix. Test results evaluated based on different codes as well as a bond database of conventional concrete specimens. These comparisons indicate that with increasing replacement level of fly ash in concrete the bond strength of reinforcing steel in concrete increases. …

Flexural Behavior Of High-Volume Fly Ash Concrete Beams: Experimental Study, Mahdi Arezoumandi, Carlos A. Ortega, Jeffery S. Volz

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

An experimental investigation was conducted to study both mechanical properties and the flexural strength of full-scale reinforced concrete beams constructed with both high-volume fly ash concrete-concrete with 70% of the cement replaced with fly ash-and conventional concrete (CC). The beams were tested under a simply supported four-point loading condition. The experimental cracking, yielding, and ultimate moments as well as deflection on ultimate load of the beams were compared with both the ACI 318-11 and Eurocode 2-05 provisions. Furthermore, the experimental flexural strengths of the beams were compared with both the modified compression field theory method and a flexural test database …

Evaluation Of An Improved Technique For Geosynthetic-Reinforced And Pile-Supported Embankment, Jun Zhang, Shao Wen Liu, He Fu Pu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

With a large number of applications of conventional technique for geosynthetic-reinforced and pile-supported (GRPS) embankment (called CT embankment), many deficiencies have been exposed. In view of the deficiencies, an improved technique, fixed-geosynthetic-reinforced and pile-supported embankment (called FGT embankment), is developed. To investigate the performance of the FGT embankment, the comparison analyses and parametric studies are conducted by Finite Element Method (FEM). The influencing factors investigated include elastic modulus of soil, tensile stiffness of geosynthetics, pile length, pile spacing, and pile elastic modulus. In addition, the cost evaluation for the FGT embankment and CT embankment is also made. The results show …

Performance Analysis And Modelling Of Hybrid Photovoltaic-Thermal Solar Panels, Nicole C. Annis

Doctoral Dissertations

A photovoltaic-thermal (PVT) panel was constructed, tested, and modelled using both MATLAB and TRNSYS. During the experimental testing, which took place on the Missouri University of Science and Technology campus in Rolla, Missouri; two identical PVT panels were tested alongside two PV panels to gather an electrical baseline for comparison. Approximately 69 days’ worth of data were of data were collected during the summer of 2014. The PV electrical, PVT electrical, PVT thermal and PVT combined (electrical and thermal) efficiencies were 3.5-5.6%, 3.4-5.4%, 20.9-11.6%, and 24.3-17.0%, respectively.

A MATLAB program was developed using existing equations for one-dimensional, quasi-steady model of …

A Revisit Of The Equilibrium Assumption For Predicting Near-Wall Turbulence, Farid Karimpour, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, we revisit the consequence of assuming equilibrium between the rates of production (P) and dissipation (∈) of the turbulent kinetic energy (k) in the highly anisotropic and inhomogeneous near-wall region. Analytical and dimensional arguments are made to determine the relevant scales inherent in the turbulent viscosity (νt) formulation of the standard k-∈ model, which is one of the most widely used turbulence closure schemes. This turbulent viscosity formulation is developed by assuming equilibrium and use of the turbulent kinetic energy (k) to infer the relevant velocity scale. We show that such turbulent viscosity formulations are not suitable …

Thickening: A 21st Century Approach For Resilience In Infrastructure, Marco Antonio Ravini

Architecture Thesis Prep

Infrastructure should be designed for higher RESILIENCE, not permanence. Rather than over-engineer to resist the inevitable failure of individual components, the next generation of public infrastructure needs to exceed its technical specifications and seek opportunistic hybridity between systems. In doing so, new possibilities for multi-layered use/outputs emerge which contribute to a more productive and resilient infrastructural lifespan.

Determining Thresholds Of Annoyance To Tones In Noise, Jennifer Marie Francis

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

Building services equipment often produce noise with prominent tones that can lead to complaints from occupants in the built environment. Previous studies have investigated human perception to tones in noise but it is still unclear at what threshold of prominence these tones lead to human annoyance. The goal of this research is to apply two different methods towards defining thresholds of annoyance to two tonal frequencies: 125 Hz and 500 Hz. In Method I – Direct Assessment with Task, subjects are exposed to 10 minutes of broadband noise with a tonal frequency set at a certain level of prominence while …

Laminar And Turbulent Regime Changes In Drinking Water Contact Tanks, Taylor C. Barnett, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Transitions in flow regimes that can occur in drinking water contact tanks may significantly affect the disinfection efficiency of the system. To demonstrate these effects, the authors investigated the internal velocity fields and flow regime of a drinking water contact tank located in Jamestown, Colo. The baffling factor (BF) of the system fluctuated annually between 0.5 and 0.6 because of a shift in flow regime caused by changes in the flow rate of the system. The authors studied the effects of the regime change from laminar to turbulent flow (or vice versa) using computational fluid dynamics (CFD) models and physical …

Designing Acoustics For Linguistically Diverse Classrooms: Effects Of Background Noise, Reverberation And Talker Foreign Accent On Speech Comprehension By Native And Non-Native English-Speaking Listeners, Z. Ellen Peng

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

The current classroom acoustics standard (ANSI S12.60-2010) recommends core learning spaces not to exceed background noise level (BNL) of 35 dBA and reverberation time (RT) of 0.6 second, based on speech intelligibility performance mainly by the native English-speaking population. Existing literature has not correlated these recommended values well with student learning outcomes. With a growing population of non-native English speakers in American classrooms, the special needs for perceiving degraded speech among non-native listeners, either due to realistic room acoustics or talker foreign accent, have not been addressed in the current standard. This research seeks to investigate the effects of BNL …

Impacts Of Climate Change On Urban Development In The Uae: The Case Of Dubai, Zainab Alrustamani Alrustamani

Theses

This thesis investigates the global calls to prepare for climate change impacts, and the role of cities to respond to it under their sustainable living approaches. It explores how the subject of climate change is integrated in the urban development process, highlighting the role of cities as contributors to the phenomenon and part of the solution. The response to climate change impacts was explored in the UAE and the emirate of Dubai. The main objective of this research is to highlight the future vision in action against climate change in the urban development framework of the emirate of Dubai, and …

Factors Affecting The Seismic Behavior Of Segmental Precast Bridge Columns, Haitham Dawood, Mohamed Elgawady, Joshua Hewes

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This manuscript discusses the design parameters that potentially affect the lateral seismic response of segmental precast post-tensioned bridge piers. The piers consist of precast circular cross section segments stacked one on top of the other with concentric tendons passing through ducts made in the segments during casting. The bottommost segments of the piers were encased in steel tubes to enhance ductility and minimize damage. An FE model was used to investigate different design parameters and how they influence the lateral force — displacement response of the piers. Design parameters investigated included the initial post-tensioning stress as a percentage of the …

Phytoscreening: A Comparison Of In Planta Portable Gc-Ms And In Vitro Analyses, Matt A. Limmer, Gregory D. Martin, Christopher J. Watson, Camilo Martinez, Joel Gerard Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Phytoscreening Has Been Proven to Rapidly Delineate Subsurface Contaminant Plumes for Semiquantitative Site Assessment, with Minimal Impact to Property or Ecology through the Collection and Analysis of Tree Cores. Here, Three Phytoscreening Methods Were Applied Concurrently to Identify Multiple Chlorinated Volatile Organic Compounds (CVOCs) in a Phytoremediation Treatment System at a Contaminated Industrial Facility. Tree Coring, in Planta Gas Chromatography-Mass Spectrometry (GC-MS), and in Planta Passive Sampling Showed General Agreement, with the in Planta GC-MS Providing the Quickest But Least Quantitative Results. the Portable GC-MS Sampling and Analysis Method Identified Six CVOCs in the Xylem of Hybrid Poplars (Populus Sp.) …

Finite Element Modelling And Dilation Of Frp-Confined Concrete Columns, Osama Youssf, Mohamed Elgawady, Julie E. Mills, Xing Ma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Concrete dilation is one of the main parameters that controls the stress-strain behavior of confined concrete. Several analytical studies have been carried out to predict the stress-strain behavior of concrete encased in fiber-reinforced polymer (FRP), which is crucial for structural design. However, none of these studies have provided a simple formula to determine the dilation parameter that is always required in the finite element (FE) material modelling of concrete. This paper presents a simple empirical model predicting the confined concrete dilation parameter within the theoretical framework of a Karagozian and Case type concrete plasticity model. A set of 105 FRP-confined …

Assessment Of Noise-Induced Annoyance By Tones In Noise From Building Mechanical Systems, Joonhee Lee, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

Prominent tones in noise generated by mechanical equipment in buildings can cause complaints from occupants in buildings. The ISO 1996-2 and ANSI S1.13 standards describe methodologies and metrics to quantify tonality perception, but the influence of tones in noise on human annoyance and performance is not fully understood yet. This paper investigates annoyance responses of humans while exposed to background noise with tonal components. Twenty participants completed digit span tasks while exposed to noise signals with differing levels of tones and overall loudness. Subjects were also asked to rate their annoyance after completing tasks under each noise signal. The subjective …