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A super-sampled projection method for level-set construction in fluid-solid interaction problems

Sandia journal manuscript; Not yet accepted for publication

Tipton, David G.

Here, this paper considers the issues central to fast level-set construction for the general treatement of moving interfaces in coupled fluid-solid interaction problems where the Lagrangian solid experiences large bulk motion. The central idea is based on a super-sampled L2 projection, that in conjunction with a Lagrangian interface position, permits rapid identification of the solid interface in the fluid mesh and enables the imposition of boundary conditions for the fluid. A series of convergence studies are presented in terms of numerical quadrature and mesh refinement to illustrate the effectiveness of the super-sampled projection on unstructured grids. The extraction of the interface location based on distance functions is compared to the super-sampled projection method. Finally, it is shown that the extraction of an interface location based on a zero level-set converges as O(h) when compared to the exact interface location - suggesting that the availability of a Lagrangian interface description is always preferred.

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TYPE Journal Article YEAR 2009
OSTI

Sandia National Laboratories, California Air Quality Program annual report

Gardizi, Leslee P.

The annual program report provides detailed information about all aspects of the SNL/CA Air Quality Program. It functions as supporting documentation to the SNL/CA Environmental Management System Program Manual. The program report describes the activities undertaken during the past year, and activities planned in future years to implement the Air Quality Program, one of six programs that supports environmental management at SNL/CA.

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TYPE SAND Report YEAR 2009
DOIOSTI

Wall pressure exerted by hydrogenation of sodium aluminum hydride

Zimmerman, Mark D.; Perras, Yon E.

Wall pressure exerted by the bulk expansion of a sodium aluminum hydride bed was measured as a function of hydrogen content. A custom apparatus was designed and loaded with sodium alanates at densities of 1.0, 1.1, and 1.16 g/cc. Four complete cycles were performed to identify variations in measured pressure. Results indicated poor correlation between exerted pressure and hydrogen capacity of the sodium alanate beds. Mechanical pressure due to the hydrogenation of sodium alanates does not influence full-scale system designs as it falls within common design factors of safety. Gas pressure gradients within the porous solid were identified and may limit reaction rates, especially for high aspect ratio beds.

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TYPE SAND Report YEAR 2009
DOIOSTI
Results 75326–75350 of 99,299
Results 75326–75350 of 99,299