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Full-Text Articles in Mechanical Engineering

Happy Hours Are A Godsend, Krishna Pakala, Diana Bairaktarova, Samantha Schauer Jun 2019

Happy Hours Are A Godsend, Krishna Pakala, Diana Bairaktarova, Samantha Schauer

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Office hours that happen in a virtual environment are called virtual office hours. This type of student-faculty interaction can be easily hosted from a faculty computer/mobile device/tablet. With an invitation, students can login to the online session and join their instructor and peers in a virtual space. Using mobile technologies, students can join virtual office hours from a variety of locations including a library, outdoors, on a commute ride home, while caring for children, eating dinner, and even while grocery shopping. Virtual office hours allow for more flexibility of student-faculty interaction. They are an alternative to traditional office ...


Work In Progress: First-Year Engineering College Students: Value Created From Participating In A Living/Learning Community, Krishna Pakala, Kim M.B. Tucker, Samantha Schauer Jun 2019

Work In Progress: First-Year Engineering College Students: Value Created From Participating In A Living/Learning Community, Krishna Pakala, Kim M.B. Tucker, Samantha Schauer

Mechanical and Biomedical Engineering Faculty Publications and Presentations

This Work in Progress paper examines how to capture the perceived value obtained from firstyear engineering college students (FYECS) from participating in the Engineering and Innovation Residential College (EIRC), a living learning community (LLC). People are social by nature and thrive through collaborating and living with others who share similar passions; however, oftentimes FYECS do not have a community of like-minded peers where support, innovation, discourse, and collaboration can take place. Adding to FYECS struggles is the fact that many do not have a mentor in their related field and are unable to start building their professional repertoire, network, technical ...


Recovery Of Stem Cell Proliferation By Low Intensity Vibration Under Simulated Microgravity Requires Linc Complex, H. Touchstone, R. Bryd, S. Loisate, M. Thompson, X. Pu, R. Beard, J. T. Oxford, G. Uzer Jan 2019

Recovery Of Stem Cell Proliferation By Low Intensity Vibration Under Simulated Microgravity Requires Linc Complex, H. Touchstone, R. Bryd, S. Loisate, M. Thompson, X. Pu, R. Beard, J. T. Oxford, G. Uzer

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Mesenchymal stem cells (MSC) rely on their ability to integrate physical and spatial signals at load bearing sites to replace and renew musculoskeletal tissues. Designed to mimic unloading experienced during spaceflight, preclinical unloading and simulated microgravity models show that alteration of gravitational loading limits proliferative activity of stem cells. Emerging evidence indicates that this loss of proliferation may be linked to loss of cellular cytoskeleton and contractility. Low intensity vibration (LIV) is an exercise mimetic that promotes proliferation and differentiation of MSCs by enhancing cell structure. Here, we asked whether application of LIV could restore the reduced proliferative capacity seen ...


Nonprehensile Manipulation Of Deformable Objects: Achievements And Perspectives From The Rodyman Project, Aykut C. Satici Sep 2018

Nonprehensile Manipulation Of Deformable Objects: Achievements And Perspectives From The Rodyman Project, Aykut C. Satici

Mechanical and Biomedical Engineering Faculty Publications and Presentations

The goal of this work is to disseminate the results achieved so far within the RODYMAN project related to planning and control strategies for robotic nonprehensile manipulation. The project aims at advancing the state of the art of nonprehensile dynamic manipulation of rigid and deformable objects to future enhance the possibility of employing robots in anthropic environments. The final demonstrator of the RODYMAN project will be an autonomous pizza maker. This article is a milestone to highlight the lessons learned so far and pave the way towards future research directions and critical discussions.


Enucleated Cells Reveal Differential Roles Of The Nucleus In Cell Migration, Polarity, And Mechanotransduction, Gunes Uzer Mar 2018

Enucleated Cells Reveal Differential Roles Of The Nucleus In Cell Migration, Polarity, And Mechanotransduction, Gunes Uzer

Mechanical and Biomedical Engineering Faculty Publications and Presentations

The nucleus has long been postulated to play a critical physical role during cell polarization and migration, but that role has not been defined or rigorously tested. Here, we enucleated cells to test the physical necessity of the nucleus during cell polarization and directed migration. Using enucleated mammalian cells (cytoplasts), we found that polarity establishment and cell migration in one dimension (1D) and two dimensions (2D) occur without the nucleus. Cytoplasts directionally migrate toward soluble (chemotaxis) and surface-bound (haptotaxis) extracellular cues and migrate collectively in scratch-wound assays. Consistent with previous studies, migration in 3D environments was dependent on the nucleus ...


Waste Heat Recovery From Distributed Rack-Based Fuel Cells Using Thermoelectric Generators, Khosrow Ebrahimi, Alfonso Ortega, Calvin Li, Kazuaki Yazawa, Sean James Jan 2018

Waste Heat Recovery From Distributed Rack-Based Fuel Cells Using Thermoelectric Generators, Khosrow Ebrahimi, Alfonso Ortega, Calvin Li, Kazuaki Yazawa, Sean James

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Off-grid power generation has been demonstrated in data centers through the deployment of site-specific centralized power plants utilizing gas turbine or fuel cell-based power generation. Because power is centrally generated, power distribution requires a high voltage power grid within the data center with its ancillary storage and conditioning requirements and equipment. An alternative approach is a completely decentralized distributed power generation system in which fuel cells deployed within individual server racks provide power localized to that rack only. Among other advantages, such an approach also greatly increases the ability to modulate and control power to individual rack units. Because the ...


Optical Properties Of Organic Carbon And Soot Produced In An Inverse Diffusion Flame, C. Russo, B. Apicella, J. S. Lighty, A. Ciajolo, A. Tregrossi Nov 2017

Optical Properties Of Organic Carbon And Soot Produced In An Inverse Diffusion Flame, C. Russo, B. Apicella, J. S. Lighty, A. Ciajolo, A. Tregrossi

Mechanical and Biomedical Engineering Faculty Publications and Presentations

The carbonaceous matter (soot plus organic carbon) sampled downstream of an ethylene inverse diffusion flame (IDF) was chemically and spectroscopically analyzed in detail. In particular, the H/C ratio, the UV-Visible absorption coefficient and Raman parameters were measured and found to be representative of a highly disordered sp2 -rich carbon as the early soot sampled in a premixed flame. In contrast, the optical band gap was found to be relatively low (0.7eV), closer to the optical band gap of graphite than to that of medium-sized polycyclic aromatic hydrocarbons (>2eV) which are widely considered to be soot precursors and ...


Direct Numerical Simulation Of Turbulent Katabatic Slope Flows With An Immersed-Boundary Method, Clancy Umphrey, Ray Deleon, Inanc Senocak Sep 2017

Direct Numerical Simulation Of Turbulent Katabatic Slope Flows With An Immersed-Boundary Method, Clancy Umphrey, Ray Deleon, Inanc Senocak

Mechanical and Biomedical Engineering Faculty Publications and Presentations

We investigate a Cartesian-mesh immersed-boundary formulation within an incompressible flow solver to simulate laminar and turbulent katabatic slope flows. As a proof-of-concept study, we consider four different immersed-boundary reconstruction schemes for imposing a Neumann-type boundary condition on the buoyancy field. Prandtl’s laminar solution is used to demonstrate the second-order accuracy of the numerical solutions globally. Direct numerical simulation of a turbulent katabatic flow is then performed to investigate the applicability of the proposed schemes in the turbulent regime by analyzing both first- and second-order statistics of turbulence. First-order statistics show that turbulent katabatic flow simulations are noticeably sensitive to ...


Dynamic Rating Of Overhead Transmission Lines Over Complex Terrain Using A Large-Eddy Simulation Paradigm, Tyler Phillips, Ray Deleon, Inanc Senocak Aug 2017

Dynamic Rating Of Overhead Transmission Lines Over Complex Terrain Using A Large-Eddy Simulation Paradigm, Tyler Phillips, Ray Deleon, Inanc Senocak

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Dynamic Line Rating (DLR) enables rating of power line conductors using real-time weather conditions. Conductors are typically operated based on a conservative static rating that assumes worst case weather conditions to avoid line sagging to unsafe levels. Static ratings can cause unnecessary congestion on transmission lines. To address this potential issue, a simulation-based dynamic line rating approach is applied to an area with moderately complex terrain. A micro-scale wind solver — accelerated on multiple graphics processing units (GPUs) — is deployed to compute wind speed and direction in the vicinity of powerlines. The wind solver adopts the large-eddy simulation technique and the ...


Detection Of Structural Bolt Detorquing Using Direct Stethoscope Measurement, Joe Guarino, Robert Hamilton Jun 2017

Detection Of Structural Bolt Detorquing Using Direct Stethoscope Measurement, Joe Guarino, Robert Hamilton

Mechanical and Biomedical Engineering Faculty Publications and Presentations

A method for detecting loosened bolts in a structural joint based upon open-loop acoustic measurement is presented. The acoustic measurement is taken directly on the bolt head. The response of the bolt to a proximal hammer impact is evaluated and characterized using wavelet decomposition of the signal measured from the bolt head. Data were also taken from an accelerometer mounted longitudinally and transversely on the bolt head. Results from the stethoscope and the accelerometer are presented from a set of structural bolts in several conditions of preload and looseness. A stethoscope applied to the loose bolt and a proximal bolt ...


A Validated Software Application To Measure Fiber Organization In Soft Tissue, Erica E. Morrill, Azamat N. Tulepbergenov, Christina J. Stender, Roshani Lamichhane, Raquel J. Brown, Trevor J. Lujan Dec 2016

A Validated Software Application To Measure Fiber Organization In Soft Tissue, Erica E. Morrill, Azamat N. Tulepbergenov, Christina J. Stender, Roshani Lamichhane, Raquel J. Brown, Trevor J. Lujan

Mechanical and Biomedical Engineering Faculty Publications and Presentations

The mechanical behavior of soft connective tissue is governed by a dense network of fibrillar proteins in the extracellular matrix. Characterization of this fibrous network requires the accurate extraction of descriptive structural parameters from imaging data, including fiber dispersion and mean fiber orientation. Common methods to quantify fiber parameters include fast Fourier transforms (FFT) and structure tensors, however, information is limited on the accuracy of these methods. In this study, we compared these two methods using test images of fiber networks with varying topology. The FFT method with a band-pass filter was the most accurate, with an error of 0 ...


Automated Measurement Of Fracture Callus In Radiographs Using Portable Software, Stephen M. Porter, Hannah L. Dailey, Katharine A. Hollar, Karina Klein, James A. Harty, Trevor J. Lujan Jul 2016

Automated Measurement Of Fracture Callus In Radiographs Using Portable Software, Stephen M. Porter, Hannah L. Dailey, Katharine A. Hollar, Karina Klein, James A. Harty, Trevor J. Lujan

Mechanical and Biomedical Engineering Faculty Publications and Presentations

The development of software applications that assist the radiographic evaluation of fracture healing could advance clinical diagnosis and expedite the identification of effective treatment strategies. A radiographic feature regularly used as an outcome measure for basic and clinical fracture healing research is new bone growth, or fracture callus. In this study, we developed OrthoRead, a portable software application that uses image-processing algorithms to detect and measure fracture callus in plain radiographs. OrthoRead utilizes an optimal boundary tracking algorithm to semi-automatically segment the cortical surface, and a novel iterative thresholding selection algorithm to then automatically segment the fracture callus. The software ...


Multidisciplinary Game-Based Approach For Generating Student Enthusiasm For Addressing Critical Infrastructure Challenges, John F. Gardner Jan 2016

Multidisciplinary Game-Based Approach For Generating Student Enthusiasm For Addressing Critical Infrastructure Challenges, John F. Gardner

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Building upon experiences from past course offering,1 several universities across the United States (U.S) have incorporated a critical infrastructure educational game platform as a unifying platform to integrate different disciplines to a common goal. The critical infrastructure backbones of the world provide the delivery mechanisms for energy and other utilities that provide the lifestyle we have come to expect in our society. As these critical infrastructure systems have evolved, the complexity of their integration has generated numerous challenges as a side effect of increased automation that are more pronounced as the infrastructure ages. Although still a modern technological ...


An Immersed Boundary Geometric Preprocessor For Arbitrarily Complex Terrain And Geometry, Inanc Senocak, Micah Sandusky, Rey Deleon, Derek Wade, Kyle Felzien, Marianna Budnikova Nov 2015

An Immersed Boundary Geometric Preprocessor For Arbitrarily Complex Terrain And Geometry, Inanc Senocak, Micah Sandusky, Rey Deleon, Derek Wade, Kyle Felzien, Marianna Budnikova

Mechanical and Biomedical Engineering Faculty Publications and Presentations

There is a growing interest to apply the immersed boundary method to compute wind fields over arbitrarily complex terrain. The computer implementation of an immersed boundary module into an existing flow solver can be accomplished with minor modifications to the rest of the computer program. However, a versatile preprocessor is needed at the first place to extract the essential geometric information pertinent to the immersion of an arbitrarily complex terrain inside a 3D Cartesian mesh. Errors in the geometric information can negatively impact the correct implementation of the immersed boundary method as part of the solution algorithm. Additionally, the distance ...


Use Of Mobile Learning Strategies And Devices For E-Portfolio Content Creation In An Engineering Thermodynamics And Fluid Mechanics Classes: Student Perceptions, Devshikha Bose, Krishna Pakala Jun 2015

Use Of Mobile Learning Strategies And Devices For E-Portfolio Content Creation In An Engineering Thermodynamics And Fluid Mechanics Classes: Student Perceptions, Devshikha Bose, Krishna Pakala

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Use of mobile learning strategies and devices for e-portfolio content creation in an engineering Thermodynamics class: Student perceptions Mobile devices can be useful for creating educational content and to help students to learn better (Benedict & Pence, 2012; Tabor & Minch, 2013; Pereira, Echeazarra, Sanz-Santamaria, & Gutierrez, 2014). The purpose of this study is to determine student perceptions on the efficacy of using mobile learning strategies and devices to create electronic content for inclusion in an engineering individual e-portfolio. Students enrolled in an undergraduate 300-level engineering Thermodynamics class, created multimedia videos and produced content demonstrating course content summaries, problem solving techniques, and written work on concept question ...


Stethoscope-Based Detection Of Detorqued Bolts Using Impact-Induced Acoustic Emissions, Joe Guarino, Robert Hamilton Jan 2015

Stethoscope-Based Detection Of Detorqued Bolts Using Impact-Induced Acoustic Emissions, Joe Guarino, Robert Hamilton

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Results of a preliminary study investigating a simple method for detecting looseness in bolted fasteners of a steel structure are presented. Extensive research by many investigators demonstrates that the frequency response of a bolted structural member changes when one or more bolts are loosened. A simple and effective method for detecting looseness can be applied to bolted joints, using inexpensive and commonly-available equipment and software. The difference between spectrograms associated with tight and loose bolts is clearly apparent due to the presence of a tell-tale mode when one or more bolts are loosened. Further, a striking difference can be elucidated ...


Characterizing Phantom Arteries With Multi-Channel Laser Ultrasonics And Photo-Acoustics, Jami L. Johnson, Kasper Van Wijk, Michelle Sabick Mar 2014

Characterizing Phantom Arteries With Multi-Channel Laser Ultrasonics And Photo-Acoustics, Jami L. Johnson, Kasper Van Wijk, Michelle Sabick

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Multi-channel photo-acoustic and laser ultrasonic waves are used to sense the characteristics of proxies for healthy and diseased vessels. The acquisition system is non-contacting and non-invasive with a pulsed laser source and a laser vibrometer detector. As the wave signatures of our targets are typically low in amplitude, we exploit multi-channel acquisition and processing techniques. These are commonly used in seismology to improve the signal-to-noise ratio of data. We identify vessel proxies with a diameter on the order of 1 mm, at a depth of 18 mm. Variations in scattered and photo-acoustic signatures are related to differences in vessel wall ...


Heavy Element Doping For Enhancing Thermoelectric Properties Of Nanostructured Zinc Oxide, Priyanka Jood, Rutvik J. Mehta, Yanliang Zhang, Theo Borca-Tasciuc, Shi Xue Dou, David J. Singh, Ganpati Ramanath Jan 2014

Heavy Element Doping For Enhancing Thermoelectric Properties Of Nanostructured Zinc Oxide, Priyanka Jood, Rutvik J. Mehta, Yanliang Zhang, Theo Borca-Tasciuc, Shi Xue Dou, David J. Singh, Ganpati Ramanath

Mechanical and Biomedical Engineering Faculty Publications and Presentations

ZnO is a high melting point, high charge carrier mobility semiconductor with potential as a thermoelectric material, but its high thermal conductivity κ is the limiting factor for increasing the thermoelectric figure of merit ZT. Here, we demonstrate that doping ZnO with heavy elements can significantly enhance ZT. Indium doping leads to ultralow κ 3 W m−1 K−1 and a high power factor α2σ 1.230 × 10−3 W m−1 K−2, yielding ZT1000K 0.45 that is 80% higher than non-nanostructured In–Zn–O alloys. Although Bi doping also yields a high Seebeck ...


Simulation Of Vertical Axis Wind Turbines With Variable Pitch Foils, L. Damon Woods, John F. Gardner, Kurt S. Myers Nov 2013

Simulation Of Vertical Axis Wind Turbines With Variable Pitch Foils, L. Damon Woods, John F. Gardner, Kurt S. Myers

Mechanical and Biomedical Engineering Faculty Publications and Presentations

A dynamic computer model of a turbine was developed in MATLAB in order to study the behavior of vertical axis wind turbines (VAWTs) with variable pitch (articulating) foils. The simulation results corroborated the findings of several empirical studies on VAWTs. The model was used to analyze theories of pitch articulation and to inform the discussion on turbine design. Simulations of various models showed that pitch articulation allowed Darrieus-style vertical axis wind turbines to start from rest. Once in motion, the rotor was found to accelerate rapidly to very high rotational velocities. The simulations revealed a plateau region of high efficiency ...


All-Optical Photoacoustic Detection Of Absorbers In Tissue Phantoms, Jami Johnson, Michelle Sabick, Kasper Vanwijk Sep 2013

All-Optical Photoacoustic Detection Of Absorbers In Tissue Phantoms, Jami Johnson, Michelle Sabick, Kasper Vanwijk

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Visualizing and characterizing vascular structures is important for many areas of health care, from accessing difficult veins and arteries for laboratory testing, to diagnosis and treatment of cardiovascular disease. Photoacoustic (PA) imaging, one of the fastest growing fields of biomedical imaging, is well suited for this task. PA imaging is based on the photoacoustic effect, which starts with a pulsed laser source incident on biological tissue. If the wavelength of the source matches an absorption wavelength of a chromophore within the tissue, a portion of the pulse energy is absorbed by the chromophore and converted into heat. A subsequent increase ...


Stochastic Reconstruction Of Multiple Source Atmospheric Contaminant Dispersion Events, Derek Wade, Inanc Senocak Aug 2013

Stochastic Reconstruction Of Multiple Source Atmospheric Contaminant Dispersion Events, Derek Wade, Inanc Senocak

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Reconstruction of intentional or accidental release of contaminants into the atmosphere using concentration measurements from a sensor network constitutes an inverse problem. An added complexity arises when the contaminant is released from multiple sources. Determining the correct number of sources is critical because an incorrect estimation could mislead and delay response efforts. We present a Bayesian inference method coupled with a composite ranking system to reconstruct multiple source contaminant release events. Our approach uses a multi-source data-driven Gaussian plume model as the forward model to predict the concentrations at sensor locations. Bayesian inference with Markov chain Monte Carlo (MCMC) sampling ...


Correlations Between Internal And External Power Outputs During Weightlifting Exercise, Kristof Kipp, Chad Harris, Michelle B. Sabick Apr 2013

Correlations Between Internal And External Power Outputs During Weightlifting Exercise, Kristof Kipp, Chad Harris, Michelle B. Sabick

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Identifying loads that maximize mechanical power is important because training at such loads may optimize gains in dynamic athletic performance. The purpose of this study was to examine correlations between measures of external mechanical power output and internal mechanical joint power output across different loads during a weightlifting exercise. Ten subjects performed 3 sets of the clean exercise at 65, 75, and 85% of 1 repetition maximum (1RM). Peak external mechanical power output was calculated with 4 commonly used methods, whereas an inverse dynamics approach was used to calculate peak internal mechanical power output for the hip, knee, and ankle ...


Multi-Level Parallelism For Incompressible Flow Computations On Gpu Clusters, Dana A. Jacobsen, Inanc Senocak Jan 2013

Multi-Level Parallelism For Incompressible Flow Computations On Gpu Clusters, Dana A. Jacobsen, Inanc Senocak

Mechanical and Biomedical Engineering Faculty Publications and Presentations

We investigate multi-level parallelism on GPU clusters with MPI-CUDA and hybrid MPI-OpenMP-CUDA parallel implementations, in which all computations are done on the GPU using CUDA. We explore efficiency and scalability of incompressible flow computations using up to 256 GPUs on a problem with approximately 17.2 billion cells. Our work addresses some of the unique issues faced when merging fine-grain parallelism on the GPU using CUDA with coarse-grain parallelism that use either MPI or MPI-OpenMP for communications. We present three different strategies to overlap computations with communications, and systematically assess their impact on parallel performance on two different GPU clusters ...


Toward A Gpu-Accelerated Immersed Boundary Method For Wind Forecasting Over Complex Terrain, Rey Deleon, Kyle Felzien, Inanc Senocak Jul 2012

Toward A Gpu-Accelerated Immersed Boundary Method For Wind Forecasting Over Complex Terrain, Rey Deleon, Kyle Felzien, Inanc Senocak

Mechanical and Biomedical Engineering Faculty Publications and Presentations

A short-term wind power forecasting capability can be a valuable tool in the renewable energy industry to address load-balancing issues that arise from intermittent wind fields. Although numerical weather prediction models have been used to forecast winds, their applicability to micro-scale atmospheric boundary layer flows and ability to predict wind speeds at turbine hub height with a desired accuracy is not clear. To address this issue, we develop a multi-GPU parallel flow solver to forecast winds over complex terrain at the micro-scale, where computational domain size can range from meters to several kilometers. In the solver, we adopt the immersed ...


Weightlifting Performance Is Related To Kinematic And Kinetic Patterns Of The Hip And Knee Joints, Kristof Kipp, Josh Redden, Michelle B. Sabick, Chad Harris Jul 2012

Weightlifting Performance Is Related To Kinematic And Kinetic Patterns Of The Hip And Knee Joints, Kristof Kipp, Josh Redden, Michelle B. Sabick, Chad Harris

Mechanical and Biomedical Engineering Faculty Publications and Presentations

The purpose of this study was to investigate correlations between biomechanical outcome measures and weightlifting performance. Joint kinematics and kinetics of the hip, knee, and ankle were calculated while ten subjects performed a clean at 85% of 1-RM. Kinematic and kinetic time-series patterns were extracted with principal components analysis. Discrete scores for each time-series pattern were calculated and used to determine how each pattern was related to body-mass normalized 1-RM. Two hip kinematic and two knee kinetic patterns were significantly correlated with relative 1-RM. The kinematic patterns captured hip and trunk motions during the first pull and hip joint motion ...


Kinematic And Kinetic Synergies Of The Lower Extremities During The Pull In Olympic Weightlifting, Kristof Kipp, Josh Redden, Michelle Sabick, Chad Harris Jul 2012

Kinematic And Kinetic Synergies Of The Lower Extremities During The Pull In Olympic Weightlifting, Kristof Kipp, Josh Redden, Michelle Sabick, Chad Harris

Mechanical and Biomedical Engineering Faculty Publications and Presentations

The purpose of this study was to identify multijoint lower extremity kinematic and kinetic synergies in weightlifting and compare these synergies between joints and across different external loads. Subjects completed sets of the clean exercise at loads equal to 65, 75, and 85% of their estimated 1-RM. Functional data analysis was used to extract principal component functions (PCF's) for hip, knee, and ankle joint angles and moments of force during the pull phase of the clean at all loads. The PCF scores were then compared between joints and across loads to determine how much of each PCF was present ...


Gpu-Accelerated Large-Eddy Simulation Of Turbulent Channel Flows, Rey Deleon, Inanc Senocak Jan 2012

Gpu-Accelerated Large-Eddy Simulation Of Turbulent Channel Flows, Rey Deleon, Inanc Senocak

Mechanical and Biomedical Engineering Faculty Publications and Presentations

High performance computing clusters that are augmented with cost and power efficient graphics processing unit (GPU) provide new opportunities to broaden the use of large-eddy simulation technique to study high Reynolds number turbulent flows in fluids engineering applications. In this paper, we extend our earlier work on multi-GPU acceleration of an incompressible Navier-Stokes solver to include a large-eddy simulation (LES) capability. In particular, we implement the Lagrangian dynamic subgrid scale model and compare our results against existing direct numerical simulation (DNS) data of a turbulent channel flow at Reτ = 180. Overall, our LES results match fairly well with the ...


Lower Extremity Biomechanics During Weightlifting Exercise Vary Across Joint And Load, Kristof Kipp, Chad Harris, Michelle B. Sabick May 2011

Lower Extremity Biomechanics During Weightlifting Exercise Vary Across Joint And Load, Kristof Kipp, Chad Harris, Michelle B. Sabick

Mechanical and Biomedical Engineering Faculty Publications and Presentations

The purpose of this study was to determine the effect of load on lower extremity biomechanics during the pull-phase of the clean. Kinematic and kinetic data of the three joints of the lower extremity were collected while participants performed multiple sets of cleans at three percentages: 65, 75, and 85% of 1-Reptition maximum (RM). General linear models with repeated measures were used to assess the influence of load on angular velocities, net torques, powers, and rates of torque development at the ankle, knee, and hip joint. The results suggest that the biomechanical demands required from the lower extremities change with ...


Scalability Of Incompressible Flow Computations On Multi-Gpu Clusters Using Dual-Level And Tri-Level Parallelism, Dana A. Jacobsen, Inanc Senocak Jan 2011

Scalability Of Incompressible Flow Computations On Multi-Gpu Clusters Using Dual-Level And Tri-Level Parallelism, Dana A. Jacobsen, Inanc Senocak

Mechanical and Biomedical Engineering Faculty Publications and Presentations

High performance computing using graphics processing units (GPUs) is gaining popularity in the scientific computing field, with many large compute clusters being augmented with multiple GPUs in each node. We investigate hybrid tri-level (MPI-OpenMP-CUDA) parallel implementations to explore the efficiency and scalability of incompressible flow computations on GPU clusters up to 128 GPUS. This work details some of the unique issues faced when merging fine-grain parallelism on the GPU using CUDA with coarse-grain parallelism using OpenMP for intra-node and MPI for inter-node communication. Comparisons between the tri-level MPI-OpenMP-CUDA and dual-level MPI-CUDA implementations are shown using computationally large computational fluid dynamics ...


A Full-Depth Amalgamated Parallel 3d Geometric Multigrid Solver For Gpu Clusters, Dana A. Jacobsen, Inanc Senocak Jan 2011

A Full-Depth Amalgamated Parallel 3d Geometric Multigrid Solver For Gpu Clusters, Dana A. Jacobsen, Inanc Senocak

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Numerical computations of incompressible flow equations with pressure-based algorithms necessitate the solution of an elliptic Poisson equation, for which multigrid methods are known to be very efficient. In our previous work we presented a dual-level (MPI-CUDA) parallel implementation of the Navier-Stokes equations to simulate buoyancy-driven incompressible fluid flows on GPU clusters with simple iterative methods while focusing on the scalability of the overall solver. In the present study we describe the implementation and performance of a multigrid method to solve the pressure Poisson equation within our MPI-CUDA parallel incompressible flow solver. Various design decisions and algorithmic choices for multigrid methods ...