A two-dimensional finite element method large eddy simulation for application to turbulent steam generator flow /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1992.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | A major concern in the nuclear power industry is failure of steam generator tubes. Failure of the steam generator tubes necessitates the plugging of the failed tubes. The consequence of steam generator tube plugging is that nuclear plants are forced to operate at lower, or derated, power levels. Premature tube failures have been attributed to a great extent to turbulence induced vibration. This turbulence induced vibration is one probable cause of premature and accelerated fretting and wear of the steam generator tubes. This research emphasizes the investigation of turbulent flow around steam generator tube arrays, while attempting to maintain a general applicability to a wide variety of two-dimensional flows. This study demonstrates a novel solution to unsteady, incompressible fluid flow problems. This approach employs Large Eddy Simulation (LES) with the Finite Element Method (FEM), a very efficient discretization method of the solution domain. A segregated solution technique, solving for each field variable at all nodes, diminishes storage requirements by eliminating the need to solve the globally assembled finite element matrix. A direct benefit is that finer nodalizations can be employed. Equal order quadrilateral elements are used to facilitate the segregated solution algorithm. The solution scheme is higher order accurate to mitigate the effects of numerical diffusion in the advection terms. The closure model for the Sub-Grid Scale (SGS) turbulence is of the Smagorinsky type. This model is easily implemented into this algorithm, and has been a generally accepted turbulence closure model. This conjunction of FEM and LES is unique. The time dependent terms are explicitly treated. The time history of a variety of physically and numerically significant flows are studied. This technique focuses on the utilization of finer nodalizations on physical flows. It is hoped that the resolution associated with mesh refinement will allow a better resolution of the turbulence, that this computational method will allow the temporal nature of turbulent flows to be studied, and that this technique will provide a framework for further study of turbulent flow phenomena. The results show the applicability of FEM/LES and determine the prospects for further development of this methodology. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Nuclear Engineering." |
| Physical Description: | xi, 151 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |