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You searched for subject:(Adaptive differencing). Showing records 1 – 2 of 2 total matches.

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University of Central Florida

1. Gerace, Salvadore. A Model Integrated Meshless Solver (mims) For Fluid Flow And Heat Transfer.

Degree: 2010, University of Central Florida

Numerical methods for solving partial differential equations are commonplace in the engineering community and their popularity can be attributed to the rapid performance improvement of modern workstations and desktop computers. The ubiquity of computer technology has allowed all areas of engineering to have access to detailed thermal, stress, and fluid flow analysis packages capable of performing complex studies of current and future designs. The rapid pace of computer development, however, has begun to outstrip efforts to reduce analysis overhead. As such, most commercially available software packages are now limited by the human effort required to prepare, develop, and initialize the necessary computational models. Primarily due to the mesh-based analysis methods utilized in these software packages, the dependence on model preparation greatly limits the accessibility of these analysis tools. In response, the so-called meshless or mesh-free methods have seen considerable interest as they promise to greatly reduce the necessary human interaction during model setup. However, despite the success of these methods in areas demanding high degrees of model adaptability (such as crack growth, multi-phase flow, and solid friction), meshless methods have yet to gain notoriety as a viable alternative to more traditional solution approaches in general solution domains. Although this may be due (at least in part) to the relative youth of the techniques, another potential cause is the lack of focus on developing robust methodologies. The failure to approach development from a practical perspective has prevented researchers from obtaining commercially relevant meshless methodologies which reach the full potential of the approach. The primary goal of this research is to present a novel meshless approach called MIMS (Model Integrated Meshless Solver) which establishes the method as a generalized solution technique capable of competing with more traditional PDE methodologies (such as the finite element and finite volume methods). This was accomplished by developing a robust meshless technique as well as a comprehensive model generation procedure. By closely integrating the model generation process into the overall solution methodology, the presented techniques are able to fully exploit the strengths of the meshless approach to achieve levels of automation, stability, and accuracy currently unseen in the area of engineering analysis. Specifically, MIMS implements a blended meshless solution approach which utilizes a variety of shape functions to obtain a stable and accurate iteration process. This solution approach is then integrated with a newly developed, highly adaptive model generation process which employs a quaternary triangular surface discretization for the boundary, a binary-subdivision discretization for the interior, and a unique shadow layer discretization for near-boundary regions. Together, these discretization techniques are able to achieve directionally independent, automatic refinement of the underlying model,… Advisors/Committee Members: Kassab, Alain.

Subjects/Keywords: meshless methods; meshless model generation; adaptive refinement; radial basis functions; moving least squares; generalized finite differencing; heat transfer; compressible fluid flow; Engineering; Mechanical Engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Gerace, S. (2010). A Model Integrated Meshless Solver (mims) For Fluid Flow And Heat Transfer. (Doctoral Dissertation). University of Central Florida. Retrieved from http://stars.library.ucf.edu/etd/4267

Chicago Manual of Style (16th Edition):

Gerace, Salvadore. “A Model Integrated Meshless Solver (mims) For Fluid Flow And Heat Transfer.” 2010. Doctoral Dissertation, University of Central Florida. Accessed March 18, 2019. http://stars.library.ucf.edu/etd/4267.

MLA Handbook (7th Edition):

Gerace, Salvadore. “A Model Integrated Meshless Solver (mims) For Fluid Flow And Heat Transfer.” 2010. Web. 18 Mar 2019.

Vancouver:

Gerace S. A Model Integrated Meshless Solver (mims) For Fluid Flow And Heat Transfer. [Internet] [Doctoral dissertation]. University of Central Florida; 2010. [cited 2019 Mar 18]. Available from: http://stars.library.ucf.edu/etd/4267.

Council of Science Editors:

Gerace S. A Model Integrated Meshless Solver (mims) For Fluid Flow And Heat Transfer. [Doctoral Dissertation]. University of Central Florida; 2010. Available from: http://stars.library.ucf.edu/etd/4267

2. Edgar, Christopher Austin. Improvements to the pool critical assembly benchmark using 3-D discrete ordinate transport with adaptive difference.

Degree: MS, Mechanical Engineering, 2013, Georgia Tech

The internationally circulated Pool Critical Assembly (PCA) Pressure Vessel Benchmark was analyzed using the PENTRAN Parallel SN code system for the geometry, material, and source specifications as described in the PCA Benchmark documentation. Improvements to the benchmark are proposed through the application of more representative flux and volume weighted homogenized cross sections for the PCA reactor core, which were obtained from a rigorous heterogeneous modeling of all fuel assembly types in the core. A new source term definition is also proposed based on calculated relative power in each core fuel assembly with a spectrum based on the Uranium-235 fission spectra. This research focused on utilizing the BUGLE-96 cross section library and accompanying reaction rates, while examining both adaptive differencing on a coarse mesh basis, as well as the sole use of Directional Theta-Weighted (DTW) SN differencing scheme in order to compare the calculated PENTRAN results to measured data. The results show good comparison with the measured data, which suggests PENTRAN is a viable and reliable code system for calculation of light water reactor neutron shielding and dosimetry calculations. Furthermore, the improvements to the benchmark methodology resulting from this work provide a 6 percent increase in accuracy of the calculation (based on the average of all calculation points), when compared with experimentally measured results at the same spatial location in the PCA pressure vessel simulator. Advisors/Committee Members: Sjoden, Glenn E. (advisor), Yi, Ce (committee member), Petrovic, Bojan (committee member), Deo, Chaitanya (committee member).

Subjects/Keywords: Discrete ordinate; Neutron transport; PENTRAN; Benchmark; Sn; Adaptive differencing; Nuclear pressure vessels; Pressure vessels; Nuclear reactors Cores; Benchmarking (Management)

…Methodology 44 Table 5.3: C/M Equivalent Fission Fluxes from PENTRAN with Adaptive Differencing… …Fluxes from PENTRAN with Adaptive Differencing using Improved Benchmark Methodology 78 Table… …Method for PENTRAN with Adaptive Differencing 78 viii LIST OF FIGURES Page Figure 2.1: PCA… …to Original Method for PENTRAN with DTW Differencing 76 Table 7.3: C/M Equivalent Fission… …Adaptive Solution at 1.0026 MeV and 0.1 eV 47 Figure 5.5: Difference Between DTW and Adaptive… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Edgar, C. A. (2013). Improvements to the pool critical assembly benchmark using 3-D discrete ordinate transport with adaptive difference. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/49087

Chicago Manual of Style (16th Edition):

Edgar, Christopher Austin. “Improvements to the pool critical assembly benchmark using 3-D discrete ordinate transport with adaptive difference.” 2013. Masters Thesis, Georgia Tech. Accessed March 18, 2019. http://hdl.handle.net/1853/49087.

MLA Handbook (7th Edition):

Edgar, Christopher Austin. “Improvements to the pool critical assembly benchmark using 3-D discrete ordinate transport with adaptive difference.” 2013. Web. 18 Mar 2019.

Vancouver:

Edgar CA. Improvements to the pool critical assembly benchmark using 3-D discrete ordinate transport with adaptive difference. [Internet] [Masters thesis]. Georgia Tech; 2013. [cited 2019 Mar 18]. Available from: http://hdl.handle.net/1853/49087.

Council of Science Editors:

Edgar CA. Improvements to the pool critical assembly benchmark using 3-D discrete ordinate transport with adaptive difference. [Masters Thesis]. Georgia Tech; 2013. Available from: http://hdl.handle.net/1853/49087

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