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Development Of Alternative Air Filtration Materials And Methods Of Analysis, Ivan Philip Beckman
Development Of Alternative Air Filtration Materials And Methods Of Analysis, Ivan Philip Beckman
Theses and Dissertations
Clean air is a global health concern. Each year more than seven million people across the globe perish from breathing poor quality air. Development of high efficiency particulate air (HEPA) filters demonstrate an effort to mitigate dangerous aerosol hazards at the point of production. The nuclear power industry installs HEPA filters as a final line of containment of hazardous particles. Advancement air filtration technology is paramount to achieving global clean air. An exploration of analytical, experimental, computational, and machine learning models is presented in this dissertation to advance the science of air filtration technology. This dissertation studies, develops, and analyzes …
Aerodynamic Design Optimization Of A Locomotive Nose Fairing For Reducing Drag, Chad Lamar Stucki
Aerodynamic Design Optimization Of A Locomotive Nose Fairing For Reducing Drag, Chad Lamar Stucki
Theses and Dissertations
Rising fuel cost has motivated increased fuel efficiency for freight trains. At cruising speed,the largest contributing factor to the fuel consumption is aerodynamic drag. As a result of stagnationand flow separation on and around lead and trailing cars, the first and last railcars experiencegreater drag than intermediate cars. Accordingly, this work focused on reducing drag on lead locomotivesby designing and optimizing an add-on nose fairing that is feasible for industrial operation.The fairing shape design was performed via computational fluid dynamic (CFD) software.The simulations consisted of two in-line freight locomotives, a stretch of rails on a raised subgrade,a computational domain, and …
Computational Investigation Using Bleed As A Method Of Shock Stabilization, Dayle L. Chang
Computational Investigation Using Bleed As A Method Of Shock Stabilization, Dayle L. Chang
Theses and Dissertations
Shock-wave/boundary layer interactions (SWBLI) produce undesirable dynamic loads and separated unsteady flows, adversely impacting the performance and structural integrity of supersonic vehicles. Computational fluid dynamics (CFD) is a successful tool in experimental planning and shows promise as a critical tool in understanding and mitigating negative effects of SWBLI. The goal of this research is to demonstrate the effect of bleed holes on shock stability using the OVERFLOW CFD solver to inform the planning of an Air Force Research Laboratory (AFRL) SWBLI wind tunnel experiment. First, a two-dimensional, flat plate, single-hole configuration was developed. Massflow discrepancies of 14.8% were initially observed …
The Development Of A Vertical-Axis Wind Turbine Wake Model For Use In Wind Farm Layout Optimization With Noise Level Constraints, Eric Blaine Tingey
The Development Of A Vertical-Axis Wind Turbine Wake Model For Use In Wind Farm Layout Optimization With Noise Level Constraints, Eric Blaine Tingey
Theses and Dissertations
This thesis focuses on providing the means to use vertical-axis wind turbines (VAWTs) in wind farms as an alternative form of harnessing wind energy in offshore and urban environments where both wake and acoustic effects of turbines are important considerations. In order for VAWTs to be used in wind farm layout analysis and optimization, a reduced-order wake model is needed to calculate velocities around a turbine quickly and accurately. However, a VAWT wake model has not been available to accomplish this task. Using vorticity data from computational fluid dynamic (CFD) simulations of VAWTs and cross-validated Gaussian distribution and polynomial surface …
Implementations Of Fourier Methods In Cfd To Analyze Distortion Transfer And Generation Through A Transonic Fan, Marshall Warren Peterson
Implementations Of Fourier Methods In Cfd To Analyze Distortion Transfer And Generation Through A Transonic Fan, Marshall Warren Peterson
Theses and Dissertations
Inlet flow distortion is a non-uniform total pressure, total temperature, or swirl (flow angularity) condition at an aircraft engine inlet. Inlet distortion is a critical consideration in modern fan and compressor design. This is especially true as the industry continues to increase the efficiency and operating range of air breathing gas turbine engines. The focus of this paper is to evaluate the Computational Fluid Dynamics (CFD) Harmonic Balance (HB) solver in STAR-CCM+ as a reduced order method for capturing inlet distortion as well as the associated distortion transfer and generation. New methods for quantitatively describing and analyzing distortion transfer and …
Analysis Of High Fidelity Turbomachinery Cfd Using Proper Orthogonal Decomposition, Ronald Alex Spencer
Analysis Of High Fidelity Turbomachinery Cfd Using Proper Orthogonal Decomposition, Ronald Alex Spencer
Theses and Dissertations
Assessing the impact of inlet flow distortion in turbomachinery is desired early in the design cycle. This thesis introduces and validates the use of methods based on the Proper Orthogonal Decomposition (POD) to analyze clean and 1/rev static pressure distortion simulation results at design and near stall operating condition. The value of POD comes in its ability to efficiently extract both quantitative and qualitative information about dominant spatial flow structures as well as information about temporal fluctuations in flow properties. Observation of the modes allowed qualitative identification of shock waves as well as quantification of their location and range of …
Using Star-Ccm+ To Evaluate Multi-User Collaboration In Cfd, Kasey Johnson Webster
Using Star-Ccm+ To Evaluate Multi-User Collaboration In Cfd, Kasey Johnson Webster
Theses and Dissertations
The client-server architecture of STAR-CCM+ allows multiple users to collaborate on a simulation set-up. The effectiveness of collaboration with this architecture is tested and evaluated on five models. The testing of these models is a start to finish set-up of an entire simulation excluding computational time for generating mesh and solving the solution. The different models have distinct differences which test every operation that would be used in a general CFD simulation. These tests focus on reducing the time spent preparing the geometry to be meshed, including setting up for a conformal mesh between multiple regions in conjugate heat transfer …
Analysis And Compression Of Large Cfd Data Sets Using Proper Orthogonal Decomposition, Trevor Jon Blanc
Analysis And Compression Of Large Cfd Data Sets Using Proper Orthogonal Decomposition, Trevor Jon Blanc
Theses and Dissertations
Efficient analysis and storage of data is an integral but often challenging task when working with computation fluid dynamics mainly due to the amount of data it can output. Methods centered around the proper orthogonal decomposition were used to analyze, compress, and model various simulation cases. Two different high-fidelity, time-accurate turbomachinery simulations were investigated to show various applications of the analysis techniques. The first turbomachinery example was used to illustrate the extraction of turbulent coherent structures such as traversing shocks, vortex shedding, and wake variation from deswirler and rotor blade passages. Using only the most dominant modes, flow fields were …
Influence Of Supraglottal Geometry And Modeling Choices On The Flow-Induced Vibration Of A Computational Vocal Fold Model, Timothy E. Shurtz
Influence Of Supraglottal Geometry And Modeling Choices On The Flow-Induced Vibration Of A Computational Vocal Fold Model, Timothy E. Shurtz
Theses and Dissertations
Computational models of the flow-induced vibrations of the vocal folds are powerful tools that can be used in conjunction with physical experiments to better understand voice production. This thesis research has been performed to contribute to the understanding of vocal fold dynamics as well as several aspects of computational modeling of the vocal folds. In particular, the effects of supraglottal geometry have been analyzed using a computational model of the vocal folds and laryngeal airway. In addition, three important computational modeling parameters (contact line location, Poisson's ratio, and symmetry assumptions) have been systematically varied to determine their influence on model …
A Computational Fluid Dynamics Feature Extraction Method Using Subjective Logic, Clifton H. Mortensen
A Computational Fluid Dynamics Feature Extraction Method Using Subjective Logic, Clifton H. Mortensen
Theses and Dissertations
Computational fluid dynamics simulations are advancing to correctly simulate highly complex fluid flow problems that can require weeks of computation on expensive high performance clusters. These simulations can generate terabytes of data and pose a severe challenge to a researcher analyzing the data. Presented in this document is a general method to extract computational fluid dynamics flow features concurrent with a simulation and as a post-processing step to drastically reduce researcher post-processing time. This general method uses software agents governed by subjective logic to make decisions about extracted features in converging and converged data sets. The software agents are designed …
Design Of A Three-Passage Low Reynolds Number Turbine Cascade With Periodic Flow Conditions, Daniel R. Rogers
Design Of A Three-Passage Low Reynolds Number Turbine Cascade With Periodic Flow Conditions, Daniel R. Rogers
Theses and Dissertations
A numerical method for modeling a low Reynolds number turbine blade, the L1M, is presented along with the pitfalls encountered. A laminar solution was confirmed to not accurately predict the flow features known in low Reynolds number turbine blade flow. Three fully turbulent models were then used to try to predict the separation and reattachment of the flow. These models were also found to be insufficient for transitioning flows. A domain was created to manually trip the laminar flow to turbulent flow using a predictive turbulence transition model. The trip in the domain introduced an instability in the flow field …
Parametric Optimization Design System For A Fluid Domain Assembly, Matthew Jackson Fisher
Parametric Optimization Design System For A Fluid Domain Assembly, Matthew Jackson Fisher
Theses and Dissertations
Automated solid modeling, integrated with computational fluid dynamics (CFD) and optimization of a 3D jet turbine engine has never been accomplished. This is due mainly to the computational power required, and the lack of associative parametric modeling tools and techniques necessary to adjust and optimize the design. As an example, the fluid domain of a simple household fan with three blades may contain 500,000 elements per blade passage. Therefore, a complete turbine engine that includes many stages, with sets of thirty or more blades each, will have hundreds of millions of elements. The fluid domains associated with each blade creates …
Numerical Simulation Of Plasma-Based Actuator Vortex Control Of A Turbulent Cylinder Wake, Nathan Keith Mcmullin
Numerical Simulation Of Plasma-Based Actuator Vortex Control Of A Turbulent Cylinder Wake, Nathan Keith Mcmullin
Theses and Dissertations
A numerical study has been performed to investigate the mechanics of the turbulent wake of a circular cylinder that is controlled by a plasma actuator. The numerical investigation implements a straightforward moving wall boundary condition to model the actuator's effects on the flow. Validations of the moving wall for this simulation are set forth with the understanding that the moving wall can model the plasma actuator bulk flow effects at a distance downstream and not in a region near or on the plasma actuator. The moving wall boundary condition is then applied to a circular cylinder at a Reynolds number …
Heat Transfer To The Inclined Trailing Wall Of An Open Cavity, Orval A. Powell
Heat Transfer To The Inclined Trailing Wall Of An Open Cavity, Orval A. Powell
Theses and Dissertations
Experimental and computational heat transfer investigations were performed on a cavity with an inclined trailing wall (20-degrees to the horizontal), simulating one under investigation for use in a scramjet engine. Heat transfer data are reported in the form of Stanton number obtained using a curve fit to the recorded transient surface temperature history under cold flow conditions. Ascending from the reattachment point, the Stanton number increased by nearly 50% due to flow compression. This effect of flow compression was also evident at the junction of the cavity floor and inclined trailing wall, where the Stanton number also increased by 50%. …