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Aerodynamic Noise Prediction For A Rod-Airfoil Configuration Using Large Eddy Simulations, Bharat R. Agrawal, Anupam Sharma 2017 Iowa State University

Aerodynamic Noise Prediction For A Rod-Airfoil Configuration Using Large Eddy Simulations, Bharat R. Agrawal, Anupam Sharma

Anupam Sharma

Aerodynamic noise produced by aerodynamic interaction between a cylinder (rod) and an airfoil in tandem arrangement is investigated using large eddy simulations. Wake from the rod convects with the flow, impinges of the airfoil to produce unsteady force which acts as a sound source. This rod-airfoil interaction problem is a model problem for noise generation due to inflow or upstream-generated turbulence interacting with a turbomachine bladerow or a wind turbine rotor. The OpenFoam and Charles (developed by Cascade Technologies) solvers are chosen to carry out the numerical simulations. The airfoil is set at zero angle of attack for the simulations ...


Numerical Investigations Of Bio-Inspired Blade Designs To Reduce Broadband Noise In Aircraft Engines And Wind Turbines, Bharat R. Agrawal, Anupam Sharma 2017 Iowa State University

Numerical Investigations Of Bio-Inspired Blade Designs To Reduce Broadband Noise In Aircraft Engines And Wind Turbines, Bharat R. Agrawal, Anupam Sharma

Anupam Sharma

Simplified representations of the leading edge serrations in owl feathers are modeled numerically to investigate their effectiveness in reducing inflow turbulence noise. The rod wake-airfoil interaction problem is selected for this investigation. Two numerical methods utilizing compressible- and incompressible large eddy simulation techniques are used for the analyses. The methods are first validated against experimental results for the baseline airfoil (no serrations). Good agreement is observed between measurement and predictions for mean surface pressure, near-field velocity spectra, and far-field sound spectra. Two serrated leading edge blade designs are then analyzed for noise. The leading edge serrations are found to give ...


On Predicting The Phenomenon Of Surface Flow Convergence In Wind Farms, Suganthi Selvaraj, Anupam Sharma 2017 Iowa State University

On Predicting The Phenomenon Of Surface Flow Convergence In Wind Farms, Suganthi Selvaraj, Anupam Sharma

Anupam Sharma

A systematic analysis of a single-rotor horizontal axis wind turbine aerodynamics is performed to obtain a realistic potential maximum efficiency. It is noted that by including the effects of swirl, viscosity and finite number of blades, the maximum aerodynamic efficiency of a HAWT is within a few percentage points of the efficiency of commercially-available turbines. The need for investigating windfarm (as a unit) aerodynamics is thus highlighted.

An actuator disk model is developed and implemented in the OpenFOAM software suite. The model is validated against 1-D momentum theory, blade element momentum theory, as well as against experimental data. The validated ...


Towards Identifying Contribution Of Wake Turbulence To Inflow Noise From Wind Turbines, Bharat R. Agrawal, Aaron Rosenberg, Anupam Sharma 2017 Iowa State University

Towards Identifying Contribution Of Wake Turbulence To Inflow Noise From Wind Turbines, Bharat R. Agrawal, Aaron Rosenberg, Anupam Sharma

Anupam Sharma

Downstream turbines in a wind farm often operate under the influence of wakes from upstream turbines. Aerodynamic losses and aeromechanical issues (stochastic loads) associated with such wake-turbine interactions have been investigated before. However, the role such interactions play in the generation of aerodynamic noise has not been evaluated. This paper presents a two-step approach for predicting noise due to wake-turbine interaction. The first step involves an aerodynamic analysis of a wind farm using large eddy simulations. Time accurate data and turbulence statistics in the turbine wakes are obtained from this simulation just ahead of the downstream wind turbines. The second ...


Inverse Design Of Horizontal Axis Wind Turbine Blades, Behnam Moghadassian, Anupam Sharma 2017 Iowa State University

Inverse Design Of Horizontal Axis Wind Turbine Blades, Behnam Moghadassian, Anupam Sharma

Anupam Sharma

A method for inverse design of horizontal axis wind turbine (HAWT) is presented in this paper. The direct solver for aerodynamic analysis solves the Reynolds Averaged Navier Stokes (RANS) equations, where the effect of the turbine rotor is modeled as momentum sources using the actuator disk model (ADM).The inverse problem is posed as follows: for a given selection of airfoils, the objective is to find the blade geometry (described as blade twist and chord distributions) which realizes the desired turbine aerodynamic performance at the design point; the desired performance is prescribed as angle of attack (α) and axial induction ...


A Smart Internet Of Things (Iot) Prototype For Accurate People Counting Towards Energy Efficient Buildings, Qian Huang 2017 Schoo of Architecture, SIUC

A Smart Internet Of Things (Iot) Prototype For Accurate People Counting Towards Energy Efficient Buildings, Qian Huang

ASA Multidisciplinary Research Symposium

According to the U.S. Department of Energy, 30% of the energy used in commercial buildings is wasted. If the number of humans in each pre-determined thermal zone is aware, a building automation system (BAS) is able to intelligently adjust HVAC operation for each thermal zone to provide “just-enough” heating, cooling and ventilation to building users. Therefore, a people counting device that can be widely deployed with low price and failure rate, small form-factor, good usability, and conserved user privacy is highly desirable. Existing room occupancy detection sensors (e.g., passive infrared, camera, acoustic, RFID, CO2) cannot meet all ...


Software Metrics And Dashboard, Shilpika Shilpika, George K. Thiruvathukal, Saulo Aguiar, Konstantin Läufer, Nicholas J. Hayward 2017 Loyola University Chicago

Software Metrics And Dashboard, Shilpika Shilpika, George K. Thiruvathukal, Saulo Aguiar, Konstantin Läufer, Nicholas J. Hayward

Konstantin Läufer

Software metrics are a critical tool which provide continuous insight to products and processes and help build reliable software in mission critical environments. Using software metrics we can perform calculations that help assess the effectiveness of the underlying software or process. The two types of metrics relevant to our work is complexity metrics and in-process metrics. Complexity metrics tend to focus on intrinsic code properties like code complexity. In-process metrics focus on a higher-level view of software quality, measuring information that can provide insight into the underlying software development process.

Our aim is to develop and evaluate a metrics dashboard ...


Power-Efficient And Highly Scalable Parallel Graph Sampling Using Fpgas, Usman Tariq, Umer Cheema, Fahad Saeed 2017 WMU

Power-Efficient And Highly Scalable Parallel Graph Sampling Using Fpgas, Usman Tariq, Umer Cheema, Fahad Saeed

Parallel Computing and Data Science Lab Technical Reports

Energy efficiency is a crucial problem in data centers where big data is generally represented by directed or undirected graphs. Analysis of this big data graph is challenging due to volume and velocity of the data as well as irregular memory access patterns. Graph sampling is one of the most effective ways to reduce the size of graph while maintaining crucial characteristics. In this paper we present design and implementation of an FPGA based graph sampling method which is both time- and energy-efficient. This is in contrast to existing parallel approaches which include memory-distributed clusters, multicore and GPUs. Our ...


Scalable Data Structure To Compress Next-Generation Sequencing Files And Its Application To Compressive Genomics, Sandino Vargas-Perez, Fahad Saeed 2017 WMU

Scalable Data Structure To Compress Next-Generation Sequencing Files And Its Application To Compressive Genomics, Sandino Vargas-Perez, Fahad Saeed

Parallel Computing and Data Science Lab Technical Reports

It is now possible to compress and decompress large-scale Next-Generation Sequencing files taking advantage of high-performance computing techniques. To this end, we have recently introduced a scalable hybrid parallel algorithm, called phyNGSC, which allows fast compression as well as decompression of big FASTQ datasets using distributed and shared memory programming models via MPI and OpenMP. In this paper we present the design and implementation of a novel parallel data structure which lessens the dependency on decompression and facilitates the handling of DNA sequences in their compressed state using fine-grained decompression in a technique that is identified as in compresso ...


Accessibility And Usability Of Government Websites In Tanzania.Pdf, Joel S. Mtebe PhD, Aron W. Kondoro 2017 University of Dar Es Salaam

Accessibility And Usability Of Government Websites In Tanzania.Pdf, Joel S. Mtebe Phd, Aron W. Kondoro

Dr. Joel S. Mtebe

The government of Tanzania has been embracing information systems specifically websites to enlarge access to government services, lower administrative costs, and to increase public participation in decision making. As a result, almost every ministry, department, and agency (MDA) has developed a unique website. However, most of existing websites were developed without sufficiently considering users’ needs which indicates that they do have some usability and accessibility problems. This study used the SortSite tool to evaluate accessibility and usability of government websites taking a sample of 22 websites. The report from the SortSite tool was then checked against the W3 WCAG accessibility ...


Feature Extraction And Parallel Visualization For Large-Scale Scientific Data, Lina Yu 2017 University of Nebraska - Lincoln

Feature Extraction And Parallel Visualization For Large-Scale Scientific Data, Lina Yu

Computer Science and Engineering: Theses, Dissertations, and Student Research

Advanced computing and sensing technologies enable scientists to study natural and physical phenomena with unprecedented precision, resulting in an explosive growth of data. The unprecedented amounts of data generated from large scientific simulations impose a grand challenge in data analytics and visualization due to the fact that data are too massive for transferring, storing, and processing.

This dissertation makes the first contribution to the design of novel transfer functions and application-aware data replacement policy to facilitate feature classification on highly parallel distributed systems. We design novel transfer functions that advance the classification of continuously changed volume data by combining the ...


Cfd Simulation Of Passenger Hazard Risk At Railway Station Platforms Due To Explosive Air Blasts, Vivian Lawrence, Sakdirat Kaewunruen, Gianni Bartoli, Charalampos Baniotopoulos 2017 University of Birmingham

Cfd Simulation Of Passenger Hazard Risk At Railway Station Platforms Due To Explosive Air Blasts, Vivian Lawrence, Sakdirat Kaewunruen, Gianni Bartoli, Charalampos Baniotopoulos

Sakdirat Kaewunruen

Safety is the first priority in operating transportation and transit systems. The public and customers rely on operators to assure them the reliable and safe day-to-day uses of public transports. However, based on recent factual evidences, extreme physical and cyber threats are no longer uncommon and these unpreventable measures are even more dangerous to the public’s daily lives. Such clear examples are the terrorist attacks in Saint Petersburg in 2017, in London in 2017, in Stockholm in 2017, in Brussels in 2016, in Nice in 2016, and so many more. These examples have one thing in common. The transportation ...


Modelling Of Convective Heat Transfer In Porous Media, Jeremy Vu 2017 The University of Western Ontario

Modelling Of Convective Heat Transfer In Porous Media, Jeremy Vu

Electronic Thesis and Dissertation Repository

This thesis details the process taken for the computational modelling of convective heat transfer in porous media. An in-house porous continuum model is modified to improve the prediction of heat transfer which is obtained when forcing fluid through porous blocks heated from one side. The results are compared to those obtained from CFD simulations performed using commercial software. Results indicated that a modification to conductivity the solid phase of the porous material must be included due to the tortuosity, or the complexity of the solid structure. Previously the tortuosity was not considered when calculating the effective solid phase conductivity.The ...


On The Ramberg-Osgood Stress-Strain Model And Large Deformations Of Cantilever Beams, Ronald J. Giardina Jr 2017 University of New Orleans

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

University of 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 ...


Web-Based Interactive Social Media Visual Analytics, Diego Rodríguez-Baquero, Jiawei Zhang, David S. Ebert, Sorin A. Matei 2017 Universidad de Los Andes - Colombia

Web-Based Interactive Social Media Visual Analytics, Diego Rodríguez-Baquero, Jiawei Zhang, David S. Ebert, Sorin A. Matei

The Summer Undergraduate Research Fellowship (SURF) Symposium

Real-time social media platforms enable quick information broadcasting and response during disasters and emergencies. Analyzing the massive amount of generated data to understand the human behavior requires data collection and acquisition, parsing, filtering, augmentation, processing, and representation. Visual analytics approaches allow decision makers to observe trends and abnormalities, correlate them with other variables and gain invaluable insight into these situations. In this paper, we propose a set of visual analytic tools for analyzing and understanding real-time social media data in times of crisis and emergency situations. First, we model the degree of risk of individuals’ movement based on evacuation zones ...


Visually Analyzing The Impacts Of Essential Air Service Funding Decisions, Rohan Kashuka, Chittayong Surakitbanharn, Calvin Yau, David S. Ebert 2017 Purdue University

Visually Analyzing The Impacts Of Essential Air Service Funding Decisions, Rohan Kashuka, Chittayong Surakitbanharn, Calvin Yau, David S. Ebert

The Summer Undergraduate Research Fellowship (SURF) Symposium

Essential Air Service (EAS) is a U.S. government subsidy program which ensures maintenance of commercial airline services in small deregulated communities. The program’s budget currently is around $250 million annually, which is used as subsidy for airlines to maintain a minimal level of scheduled air service in relatively smaller airports. It is evident that 2% of the FAA budget is being spent to maintain air service in smaller communities, but there is not enough evidence to prove that all the current decisions made by Congress about EAS are advantageous. To understand these decisions, 15 years of data produced ...


On Accelerating Source Code Analysis At Massive Scale, Ganesha Upadhyaya, Hridesh Rajan 2017 Iowa State University

On Accelerating Source Code Analysis At Massive Scale, Ganesha Upadhyaya, Hridesh Rajan

Computer Science Technical Reports

Encouraged by the success of data-driven software engineering (SE) techniques that have found numerous applications e.g. in defect prediction, specification inference, etc, the demand for mining and analyzing source code repositories at scale has significantly increased. However, analyzing source code at scale remains expensive to the extent that data-driven solutions to certain SE problems are beyond our reach today. Extant techniques have focussed on leveraging distributed computing to solve this problem, but with a concomitant increase in computational resource needs. This work proposes a technique that reduces the amount of computation performed by the ultra-large-scale source code mining task ...


The Effect Of Bone And Ligament Morphology Of Ankle Joint Loading In The Neutral Position, Jinhyuk Kim 2017 Old Dominion University

The Effect Of Bone And Ligament Morphology Of Ankle Joint Loading In The Neutral Position, Jinhyuk Kim

Mechanical & Aerospace Engineering Theses & Dissertations

Computational modeling of joints is used to investigate the effect of injuries, to plan surgeries, and to answer questions about joints that cannot be answered experimentally. Existing models of the ankle joint are moving toward being able to model specific patients, however, they do not include all of the anatomy (e.g., bones and/or ligaments) and have restrictive boundary conditions. These simplification in anatomy are made to minimize pre-processing and computation time. Because biomechanical modeling is increasingly focused on the implementation of patient specific cases, the effects of including more anatomical structures and determining how they affect the model ...


Iota: Internet Of Things Assistant, Brandon M. Okumura 2017 California Polytechnic State University, San Luis Obispo

Iota: Internet Of Things Assistant, Brandon M. Okumura

Master's Theses and Project Reports

The Internet of Things is the networking of electronic devices, or “Things”, that enables them to collect and share data, as well as interact with their physical surround- ings. Analyzing this collected data allows us to make smarter economic decisions. These interconnected networks are usually driven by low-powered micro-controllers or cheap CPUs that are designed to function optimally with very little hardware. As scale and computational requirements increase, these micro-controllers are unable to grow without being physically replaced.

This thesis proposes a system, IoTA, that assists the Internet of Things by pro- viding a shared computational resource for endpoint devices ...


A Hardware One-Time Pad Prototype Generator For Localising Cloud Security, Paul Tobin, Lee Tobin, Michael mcKeever, Jonathan Blackledge Professor 2017 Dublin Institute of Technology

A Hardware One-Time Pad Prototype Generator For Localising Cloud Security, Paul Tobin, Lee Tobin, Michael Mckeever, Jonathan Blackledge Professor

Conference papers

In this paper, we examine a system for encrypting data before storing in the Cloud. Adopting this system gives excellent security to stored data and complete control for accessing data by the client at different locations. The motivation for developing this personal encryption came about because of poor Cloud security and doubts over the safety of public encryption algorithms which might contain backdoors. However, side-channel attacks and other unwanted third-party interventions in Cloud security, probably contribute more to the poor security record history. These factors led to the development of a prototype for personalising security locally which defeats cryptanalysis. The ...


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