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Computational fluid dynamics

Brigham Young University

Articles 1 - 10 of 10

Full-Text Articles in Mechanical Engineering

The Development Of A Vertical-Axis Wind Turbine Wake Model For Use In Wind Farm Layout Optimization With Noise Level Constraints, Eric Blaine Tingey Mar 2017

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 Jun 2016

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 Mar 2016

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 ...


Using Star-Ccm+ To Evaluate Multi-User Collaboration In Cfd, Kasey Johnson Webster Oct 2015

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 Jul 2014

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 Nov 2011

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 ...


A Computational Fluid Dynamics Feature Extraction Method Using Subjective Logic, Clifton H. Mortensen Jul 2010

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 Nov 2008

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 Apr 2008

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 ...


Numerical Simulation Of Plasma-Based Actuator Vortex Control Of A Turbulent Cylinder Wake, Nathan Keith Mcmullin Sep 2006

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 ...