Computational Engineering Commons^™

Prediction Of Flood Hydrograph In Small River Catchments Using System Modelling Approach, Ahmed Nasr, Zeinab Bedri, Loreta Ramanauske

Conference papers

Floods remain to be one of the natural catastrophic disasters with serious adverse social and economic implications on individuals and communities all around the world. In Ireland, frequency of flood events have increased dramatically during the last forty years and is expected to continue to rise primarily due to changes in rainfall and temperature patterns as a result of the global climate change. Small river catchments are usually vulnerable to different types of flooding particularly those associated with “monster” rainfall events, which are characterised by short durations and high intensities. Therefore accurate prediction of flood hydrographs resulting from these rainfall …

Modeling The Impacts Of Sea Level Rise On Storm Surge Inundation In Flood-Prone Urban Areas Of Hampton Roads, Virginia, Luca Castrucci, Navid Tahvildari

Civil & Environmental Engineering Faculty Publications

Hampton Roads is a populated area in the United States Mid-Atlantic region that is highly affected by sea level rise (SLR). The transportation infrastructure in the region is increasingly disrupted by storm surge and even minor flooding events. The purpose of this study is to improve our understanding of SLR impacts on storm surge flooding in the region. We develop a hydrodynamic model to study the vulnerability of several critical flood-prone neighborhoods to storm surge flooding under several SLR projections. The hydrodynamic model is validated for tide prediction, and its performance in storm surge simulation is validated with the water …

On The Ramberg-Osgood Stress-Strain Model And Large Deformations Of Cantilever Beams, Ronald J. Giardina Jr

LSU New Orleans Theses and Dissertations

In this thesis the Ramberg-Osgood nonlinear model for describing the behavior of many different materials is investigated. A brief overview of the model as it is currently used in the literature is undertaken and several misunderstandings and possible pitfalls in its application is pointed out, especially as it pertains to more recent approaches to finding solutions involving the model. There is an investigation of the displacement of a cantilever beam under a combined loading consisting of a distributed load across the entire length of the beam and a point load at its end and new solutions to this problem are …

Numerical Modeling And Seismic Assessment Of Smart Isolation System For High-Speed Railway Rc Bridge Subjected To Near-Field Ground Motions, Lingkun Chen

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.

Accuracy Comparison Of Numerical Integration Algorithms For Real-Time Hybrid Simulations, Ganesh Anant Reddy

Civil & Environmental Engineering Theses & Dissertations

The use of accurate numerical integration algorithms is one of the key factors for a successful real-time hybrid simulation (RTHS). In RTHSs, explicit integration algorithms are preferred more than implicit methods since all calculations need to be completed within a given time step during simulation. Explicit methods require the use of effective stiffness and damping for experimental substructures, which are incorporated into the calculation of the integration parameters. In general, those values that are greater than the expected stiffness and damping of the experimental substructure are used to ensure the stability of simulation. If a rate-dependent and nonlinear experimental substructure …

A Modified Rank Ordered Logit Model To Analyze Injury Severity Of Occupants In Multi-Vehicle Crashes, Shelley Bogue

Civil & Environmental Engineering Theses & Dissertations

Research on methodological approaches to model injury severity has become important in order to prevent crash fatalities. Roadways have always been dangerous, with significant congestion and uncontrollable variables, such as weather, coupled with road users' decisions including seat belt and alcohol/drug use. These decisions can influence the severity of injuries sustained by vehicle occupants in the event of a crash. Few studies have examined the potential impacts of comprehensive roadway user injury severity profiles of all occupants ( drivers as well as passengers) in all vehicles involved in a crash. The focus of past studies has been on examining the …

Real-Time Hybrid Simulation With Online Model Updating, Adam Mueller

Masters Theses

Hybrid simulations have shown great potential for economic and reliable assessment of structural seismic performance through a combination of physically tested components, called the experimental substructure, and numerically simulated components, called the numerical substructure. Current hybrid simulation practices often use a fixed numerical model without considering the possible availability of a more accurate model obtained during hybrid simulation through an online model updating technique. To address this limitation and improve the reliability of numerical models in hybrid simulations, this study describes the implementation of an online model updating method in real-time hybrid simulation (RTHS). The Unscented Kalman Filter (UKF) was …

Thermal Numerical Analysis Of Vertical Heat Extraction Systems In Landfills, Michael Thomas Onnen

Master's Theses

An investigation was conducted to determine the response of landfills to the operation of a vertical ground source heat pump (i.e., heat extraction system, HES). Elevated landfill temperatures, reported various researchers, impact the engineering performance of landfill systems. A numerical model was developed to analyze the influence of vertical HES operation on landfills as a function of climate and operational conditions.

A 1-D model of the vertical profile of a landfill was developed to approximate fluid temperatures in the HES. A 2-D model was then analyzed over a 40 year time period using the approximate fluid temperatures to determine the …

Two-Dimensional Hydrodynamic Modeling Of Two-Phase Flow For Understanding Geyser Phenomena In Urban Stormwater System, Zhiyu S. Shao

Theses and Dissertations--Civil Engineering

During intense rain events a stormwater system can fill rapidly and undergo a transition from open channel flow to pressurized flow. This transition can create large discrete pockets of trapped air in the system. These pockets are pressurized in the horizontal reaches of the system and then are released through vertical vents. In extreme cases, the transition and release of air pockets can create a geyser feature.

The current models are inadequate for simulating mixed flows with complicated air-water interactions, such as geysers. Additionally, the simulation of air escaping in the vertical dropshaft is greatly simplified, or completely ignored, in …

Smart Home Prototype, Logistics & Planning, David G. Guzman^, Virgilio Gonzalez*

COURI Symposium Abstracts, Spring 2012

No abstract provided.

Simulation, Visualization And Self-Assessment Tools For Enhanced Engineering Education The Stiffness Matrix Method Module For Structural Analysis, Ahmed Ali Mohammed

Civil & Environmental Engineering Theses & Dissertations

Existing macromedia FLASH software which has extensive and exciting simulation and visualization capabilities is utilized to develop the "Stiffness Matrix Method" (SMM) module, which is one of the new topics ( offered for the first time in Spring 2007 semester) covered in a Structural Analysis I course, offered at the junior level at Old Dominion University. The developed software (under the FLASH environment), including tutorial lectures to explain all necessary theoretical backgrounds, formulas, step-by-step computerized procedures and numerical examples are presented in simple, user friendly, visualized, interactive fashion to enhance the student's learning capabilities. Through numerous graphical visualization and simulation …

A Dynamic Simulation Model Of Beach Sand Replenishment: A Case Study Of Santa Barbara, California, David Turbow, Steve Norwick, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Sediment deprivation from dam installments contributes to beach erosion yet the underlying physical and economic factors linking them together have traditionally been isolated during regional planning. In order to gain a better understanding of the behavior of a managed beach system, a dynamic simulation model was developed incorporating physical and monetary factors influencing the amount of available beach sand. The Santa Barbara littoral cell was chosen as a case study to evaluate the feasibility of beach preservation goals under scenarios in which annual sand replenishment funding, sand prices, or sediment recovery from behind dams were limiting factors to available beach …

The Effects Of Offshore Mining Of Beach Quality Sediments On Nearshore Wave Climate, Frank R. Lonza

Civil & Environmental Engineering Theses & Dissertations

Coastal communities rely on the beaches to attract tourism, but these sources of revenue require maintenance, such as beach nourishment. In an effort to maintain these beaches without causing any detrimental results, research is conducted to determine what effects, if any, exist when mining for sand in offshore areas.

The U.S. Government is permitting the search for beach quality sands offshore but is also ensuring that such mining will not have adverse results to the nearshore wave climate. This study was conducted using a coarse grid bathymetric map to calibrate a numerical model developed by the Danish Hydraulic Institute (DHI). …

A Two Dimensional Distributed Hydrological Model For Infiltrating Watersheds With Channel Networks, Donald Lee Currey

Civil & Environmental Engineering Theses & Dissertations

A numerical model named Old Dominion Watershed Simulation Model (ODWSM) is developed for simulating the rainfall/runoff process that occurs over watersheds. ODWSM's computational modules include the capability to simulate two-dimensional overland flow, spatially varied infiltration and depression storage, interception and channel flow for irregular and looped networks.

Overland flow computation is performed by writing the two-dimensional kinematic wave equations in an implicit finite difference form. Computational speed is gained by using an upwind differencing scheme and solving the equations in the direction of flow. This solution method allows for the calculation of infiltration and depression storage to include rainfall, current …

A Receiving Water Quality Model For Dissolved Metal Runoff From A Floating Drydock, Thomas O. Fenn

Civil & Environmental Engineering Theses & Dissertations

A methodology for modeling the water quality mixing zone of dissolved metal bearing storm water runoff is presented with specific application to floating drydocks in a tidal estuary. The method relies upon a solution of the mass balance equation as contained in the computer program, Water Quality Analysis Simulation Program (WASPS), an Environmental Protection Agency (EPA) model. Separate applications are presented for dissolved metal and solid settling to optimize the WASPS program capabilities.

WASPS provides the capability to evaluate the mass balance equation in a finite difference scheme applied over a large number of small volume segments. The program may …

The Frontal Method For Finite Element Analysis On Ibm-3090 Vector Computer, Chaerul Kamal

Civil & Environmental Engineering Theses & Dissertations

In this report, a Finite Element program based on the Frontal method was implemented on the IBM-3090 to exploit the vector capabilities offered by modern high performance vector computers. The overall computational speed for the Frontal Finite Element program was increased by 30% when the vector instructions were introduced. The Frontal solution for a system of simultaneous linear equations, however, has shown only minor improvement when vector instructions were used. More improvement in computational speed and memory storage can be expected by using the Parallel Frontal method with Substructures.

Dynamic Analysis Of Linear Structural System Using Ritz Vector Method And Substructuring Formulation, Vijay R. Modi

Civil & Environmental Engineering Theses & Dissertations

In this study, the substructuring formulation is incorporated into Ritz Vector method to obtain and solve the reduced system of dynamic equilibrium equations. Two-dimensional and three-dimensional truss problems are considered in the present study. The accuracy and computational time using the proposed technique are compared with known solutions. The effect of using different number of substructures and Ritz vectors are also investigated, equations solver is utilized to Moreover, a version of a parallel further enhance the numerical performance of the proposed technique on the FLEX/32 Multicomputer.

Comparison Of Steady-State Pipe Network Computer Programs, Michael Bernice Holloway

Civil & Environmental Engineering Theses & Dissertations

Four widely used computer programs for the analysis of steady state flows in pipe networks are compared. These programs are NEWTH, written by Jeppson; KENTUCKY, written by Wood; FLOW, written by Epp and Fowler; and LIQSS, written by Stoner. Differences, similarities, advantages and disadvantages of these programs, and various options available are discussed for the benefit of possible future users. In addition, the efficiency of NEWTH, KENTUCKY, and FLOW was tested by simulating a typical network by each program. The listing of LIQSS was not available, and thus was not included in this comparison. In simulation, KENTUCKY used over twice …