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One dimensional multi-phase moving boundary problems with phases of different densities

Description: Density changes occur naturally in phase change problems. It is customary in analyzing such problems to ignore the bulk movement of material thus introduced and assume the densities to be equal. However, for one dimensional problems the complexity introduced by this bulk movement is more apparent than real. This can be demonstrated by posing the problem in local coordinates fixed in each phase. In this report we show how to define suitable moving coordinates and, using them, pose and solve a one dimensional, multi-phase Stefan problem with phases of distinct densities. This explicit solution is essentially a similarity solution in the local coordinates. However, utility of these local coordinates is not limited to problems for which similarity solutions exist. They could be used with finite element or finite difference schemes to analyze more complex problems.
Date: January 1, 1982
Creator: Wilson, D.G.
Partner: UNT Libraries Government Documents Department

Mushy-zone model with an exact solution

Description: In this paper we propose a very simple model of a mushy zone which admits of an explicit solution. To our knowledge, it is the only instance where an actual observation of the mushy zone width and structure is used as a partial basis for the model definition. The model rests upon two unknown parameters. The first determines the relation between the equilibrium temperature gradient and the mushy zone width. The second depends upon the dendritic structure in the mushy zone, and is related to the solid fraction. Both can be estimated from experiments. We will limit ourselves to defining the model, presenting its closed form solution, and giving tables from which the solution can be found explicitly. It is shown that in most cases the predicted mushy zone is of very negligible importance.
Date: April 1, 1982
Creator: Solomon, A. D.; Wilson, D. G. & Alexiades, V.
Partner: UNT Libraries Government Documents Department

Bibliography on moving boundary problems with key word index

Description: This bibliography concentrates mainly on time-dependent moving-boundary problems of heat and mass transfer. The bibliography is in two parts, a list of the references ordered by last name of the first author and a key word index to the titles. Few references from before 1965 are included. (RWR)
Date: October 1, 1979
Creator: Wilson, D.G.; Solomon, A.D. & Trent, J.S.
Partner: UNT Libraries Government Documents Department

Feed-pump hydraulic performance and design improvement, Phase I: research program design. Final report

Description: As a result of prior EPRI-sponsored studies, it was concluded that a research program should be designed and implemented to provide an improved basis for the design, procurement, testing, and operation of large feed pumps with increased reliability and stability over the full range of operating conditions. This two-volume report contains a research plan which is based on a review of the present state of the art and which defines the necessary R and D program and estimates the benefits and costs of the program. The recommended research program consists of 30 interrelated tasks. It is designed to perform the needed research; to verify the results; to develop improved components; and to publish computer-aided design methods, pump specification guidelines, and a troubleshooting manual. Most of the technology proposed in the research plan is applicable to nuclear power plants as well as to fossil-fired plants. This volume contains appendixes on pump design, cavitation damage, performance testing, hydraulics, two-phase flow in pumps, flow stability, and rotor dynamics.
Date: March 1, 1982
Creator: Brown, W.H.; Gopalakrishnan, S.; Fehlau, R.; Thompson, W.E. & Wilson, D.G.
Partner: UNT Libraries Government Documents Department

Feed-pump hydraulic performance and design improvement, Phase I: research program design. Final report

Description: As a result of prior EPRI-sponsored studies, it was concluded that a research program should be designed and implemented to provide an improved basis for the design, procurement, testing, and operation of large feed pumps with increased reliability and stability over the full range of operating conditions. This two-volume report contains a research plan which is based on a review of the present state of the art and which defines the necessary R and D program and estimates the benefits and costs of the program. The recommended research program consists of 30 interrelated tasks. It is designed to perform the needed research; to verify the results; to develop improved components; and to publish computer-aided design methods, pump specification guidelines, and a troubleshooting manual. Most of the technology proposed in the research plan is applicable to nuclear power plants as well as to fossil-fired plants. This volume discusses the design, performance and failures of feed pumps, and recommendations for research on pump dynamics, design, and specifications.
Date: March 1, 1982
Creator: Brown, W.H.; Gopalakrishnan, S.; Fehlau, R.; Thompson, W.E. & Wilson, D.G.
Partner: UNT Libraries Government Documents Department

Design of a high-power density Ljungstrom turbine using potassium as a working fluid

Description: The ability to generate large quantities of high-quality power in space will be necessary to meet the needs of many proposed future space programs. The Pacific Northwest Laboratory is studying an advanced multi-megawatt space power system employing a liquid metal Rankine power cycle. This paper examines more closely one component of the system, the power turbine. The turbine design selected for this system is a counter-rotating radial-outflow machine developed in the early twentieth century by two brothers, Fredrik and Birger Ljungstroem turbine was selected because it provides a compact, high-power-density turbine with balanced rotational inertia and is tolerant of moisture in the working fluid. In commercial operation, Ljungstroem turbines have demonstrated excellent rapid start capabilities and good overall efficiency. Moreover, the disadvantages that have hindered its use in conventional power plants are tied to the steam's very large change in specific volume. These disadvantages are circumvented in a machine using potassium for a working fluid. A preliminary design study indicates that high-power turbines, using potassium as a working fluid, are feasible for the Ljungstroem turbine, and that Ljungstroem turbines of 200 MW and greater could easily fit into the cargo bay of the space shuttle. 10 refs., 5 figs. 3 tabs.
Date: April 1, 1986
Creator: Coomes, E.P.; Dodge, R.E.; Wilson, D.G. & McCabe, S.J.
Partner: UNT Libraries Government Documents Department

Optimized input shaping for a single flexible robot link

Description: This paper will discuss the design of an input shaped open-loop control for a single flexible robot link. The authors develop the equations of motion, including the first flexible mode shape and the actuator dynamics. Additional content includes the hardware system identification iterative runs used to update the model. Optimized input shaped commands for the flexible robot link to produce a rest-to-rest, residual vibration-free, 90 degree maneuver are developed. Correlation between both experimental and analytical results of the 90{degree} slew, using two different identification models, are reviewed.
Date: March 1, 1996
Creator: Wilson, D.G.; Stokes, D.; Starr, G. & Robinett, R.D.
Partner: UNT Libraries Government Documents Department

Mathematics and statistics research progress report, period ending June 30, 1983

Description: This report is the twenty-sixth in the series of progress reports of Mathematics and Statistics Research of the Computer Sciences organization, Union Carbide Corporation Nuclear Division. Part A records research progress in analysis of large data sets, applied analysis, biometrics research, computational statistics, materials science applications, numerical linear algebra, and risk analysis. Collaboration and consulting with others throughout the Oak Ridge Department of Energy complex are recorded in Part B. Included are sections on biological sciences, energy, engineering, environmental sciences, health and safety, and safeguards. Part C summarizes the various educational activities in which the staff was engaged. Part D lists the presentations of research results, and Part E records the staff's other professional activities during the report period.
Date: August 1, 1983
Creator: Beauchamp, J. J.; Denson, M. V.; Heath, M. T.; Lever, W. E. & Wilson, D. G.
Partner: UNT Libraries Government Documents Department

Mathematics and Statistics Research Department progress report for period ending June 30, 1978. [ORNL]

Description: This report is the twenty-first of a series of annual reports dating back to the February 28, 1957, report of the ORNL Mathematics Panel. The current report is divided into five parts: Mathematical and Statistical Research, Statistical and Mathematical Collaboration, Educational Activities, Presentations of Research Results, and Professional Activities. The section entitled Mathematical and Statistical Research contains summaries of the research conducted on Moving Boundary Problems, Multivariate Multipopulation Classification, Numerical Linear Algebra, Statistical Model Development and Evaluation, Materials Science Applications, Biomedical and Environmental Applications, and Complementary Areas. Recorded under Statistical and Mathematical Collaboration are brief accounts of consulting and collaboration with other scientists and engineers in the Nuclear Division of Union Carbide Corporation. These are in the areas of Analytical Chemistry, Biology, Chemistry and Physics, Engineering, Environmental Sciences, Materials Sciences, Security and Communication, and Uranium Resource Evaluation. The Educational Activities section contains descriptions of symposia, workshops, seminar series, short courses, lectures, and student and faculty participation in which the staff was engaged during the report period. The last two parts of the report list the staff's publications and oral presentations as well as its participation in the activities of professional societies and academic institutions. The summaries given here are quite brief; completed work is published in journals or reports as appropriate. 7 figures, 8 tables.
Date: September 1, 1978
Creator: Gardiner, D.A.; Lever, W.E.; Shepherd, D.E.; Ward, R.C. & Wilson, D.G. (comps.)
Partner: UNT Libraries Government Documents Department

Low-pressure-ratio regenerative exhaust-heated gas turbine

Description: A design study of coal-burning gas-turbine engines using the exhaust-heated cycle and state-of-the-art components has been completed. In addition, some initial experiments on a type of rotary ceramic-matrix regenerator that would be used to transfer heat from the products of coal combustion in the hot turbine exhaust to the cool compressed air have been conducted. Highly favorable results have been obtained on all aspects on which definite conclusions could be drawn.
Date: January 1, 1991
Creator: Tampe, L.A.; Frenkel, R.G.; Kowalick, D.J.; Nahatis, H.M.; Silverstein, S.M. & Wilson, D.G.
Partner: UNT Libraries Government Documents Department

Low-pressure-ratio regenerative exhaust-heated gas turbine. Final report

Description: A design study of coal-burning gas-turbine engines using the exhaust-heated cycle and state-of-the-art components has been completed. In addition, some initial experiments on a type of rotary ceramic-matrix regenerator that would be used to transfer heat from the products of coal combustion in the hot turbine exhaust to the cool compressed air have been conducted. Highly favorable results have been obtained on all aspects on which definite conclusions could be drawn.
Date: January 1, 1991
Creator: Tampe, L. A.; Frenkel, R. G.; Kowalick, D. J.; Nahatis, H. M.; Silverstein, S. M. & Wilson, D. G.
Partner: UNT Libraries Government Documents Department