4,941 research outputs found
MAG3D and its application to internal flowfield analysis
MAG3D (multiblock adaptive grid, 3D) is a 3D solution-adaptive grid generation code which redistributes grid points to improve the accuracy of a flow solution without increasing the number of grid points. The code is applicable to structured grids with a multiblock topology. It is independent of the original grid generator and the flow solver. The code uses the coordinates of an initial grid and the flow solution interpolated onto the new grid. MAG3D uses a numerical mapping and potential theory to modify the grid distribution based on properties of the flow solution on the initial grid. The adaptation technique is discussed, and the capability of MAG3D is demonstrated with several internal flow examples. Advantages of using solution-adaptive grids are also shown by comparing flow solutions on adaptive grids with those on initial grids
Interactive solution-adaptive grid generation procedure
TURBO-AD is an interactive solution adaptive grid generation program under development. The program combines an interactive algebraic grid generation technique and a solution adaptive grid generation technique into a single interactive package. The control point form uses a sparse collection of control points to algebraically generate a field grid. This technique provides local grid control capability and is well suited to interactive work due to its speed and efficiency. A mapping from the physical domain to a parametric domain was used to improve difficulties encountered near outwardly concave boundaries in the control point technique. Therefore, all grid modifications are performed on the unit square in the parametric domain, and the new adapted grid is then mapped back to the physical domain. The grid adaption is achieved by adapting the control points to a numerical solution in the parametric domain using control sources obtained from the flow properties. Then a new modified grid is generated from the adapted control net. This process is efficient because the number of control points is much less than the number of grid points and the generation of the grid is an efficient algebraic process. TURBO-AD provides the user with both local and global controls
NASA Workshop on future directions in surface modeling and grid generation
Given here is a summary of the paper sessions and panel discussions of the NASA Workshop on Future Directions in Surface Modeling and Grid Generation held a NASA Ames Research Center, Moffett Field, California, December 5-7, 1989. The purpose was to assess U.S. capabilities in surface modeling and grid generation and take steps to improve the focus and pace of these disciplines within NASA. The organization of the workshop centered around overviews from NASA centers and expert presentations from U.S. corporations and universities. Small discussion groups were held and summarized by group leaders. Brief overviews and a panel discussion by representatives from the DoD were held, and a NASA-only session concluded the meeting. In the NASA Program Planning Session summary there are five recommended steps for NASA to take to improve the development and application of surface modeling and grid generation
Thermophysical properties of a Cu46Zr42Al7Y5 bulk metallic glass-forming liquid
The thermophysical properties, including the specific volume V, the surface tension sigma, and the viscosity eta, of a Cu46Zr42Al7Y5 bulk metallic glass in the molten state were investigated using a containerless high-temperature high-vacuum electrostatic levitation technique. The viscosity measurements indicate that the Cu46Zr42Al7Y5 alloy exhibits an intermediate fragility with the fragility index m=49
Scoping study on natural resources and climate change in Southeast Asia with a focus on agriculture. Final report
Climate change / Natural resources / Environmental effects / Agroecology / Agricultural production / Crops / Cropping systems / Farming systems / Livestock / Fisheries / Food security / Water management / Economic aspects / Rural poverty / Policy / Nutrient management / South East Asia / Cambodia / Laos / Thailand / Vietnam / Myanmar / China / Greater Mekong Subregion / Tonle Sap / Yunnan
The nonlinear Bernstein-Schr\"odinger equation in Economics
In this paper we relate the Equilibrium Assignment Problem (EAP), which is
underlying in several economics models, to a system of nonlinear equations that
we call the "nonlinear Bernstein-Schr\"odinger system", which is well-known in
the linear case, but whose nonlinear extension does not seem to have been
studied. We apply this connection to derive an existence result for the EAP,
and an efficient computational method.Comment: 8 pages, submitted to Lecture Notes in Computer Scienc
Health Informatics and E-health Curriculum for Clinical Health Profession Degrees
This article is published online with Open Access by IOS Press and distributed under the terms
of the Creative Commons Attribution Non-Commercial License.The project reported in this paper models a new approach to making health informatics and e-health education widely available to students in a range of Australian clinical health profession degrees. The development of a Masters level subject uses design-based research to apply educational quality assurance practices which are consistent with university qualification frameworks, and with clinical health profession education standards; at the same time it gives recognition to health informatics as a specialised profession in its own right. The paper presents details of (a) design with reference to the Australian Qualifications Framework and CHIA competencies, (b) peer review within a three-university teaching team, (c) external review by experts from the professions, (d) cross-institutional interprofessional online learning, (e) methods for evaluating student learning experiences and outcomes, and (f) mechanisms for making the curriculum openly available to interested parties. The project has sought and found demand among clinical health professionals for formal health informatics and e-health education that is designed for them. It has helped the educators and organisations involved to understand the need for nuanced and complementary health informatics educational offerings in Australian universities. These insights may aid in further efforts to address substantive and systemic challenges that clinical informatics faces in Australia
Climate change, water and agriculture in the Greater Mekong subregion
Climate change / Adaptation / Indicators / Water resource management / River basins / Water availability / Water quality / Groundwater / Fisheries / Ecosystems / Water power / Population growth / Land use / Biofuels / Sea level / South East Asia / Cambodia / Laos / Myanmar / Thailand / Vietnam / China / Greater Mekong Subregion / Yunnan Province
RANS and DES Computations for a Wing with Ice Accretion
A computational investigation was performed to assess the effectiveness of Detached Eddy Simulation (DES) as a tool for predicting icing effects. The AVUS code, a public domain flow solver, was employed to compute solutions for an iced wing configuration using DES and steady Reynolds Averaged Navier-Stokes (RANS) equation methodologies. The wing section considered here was a business jet airfoil (GLC305) with a 22.5-minute glaze ice accretion (944-ice shape). The section was extruded to form a rectangular planform. The model was mounted between two walls so no tip effects were considered. The numerical results were validated by comparison with experimental data for the same configuration. The time-averaged DES computations showed some improvement in lift and drag results near stall when compared to steady RANS results. However, comparisons of the flow field details did not show the level of agreement suggested by the integrated quantities. More validation is needed to determine what role DES can play as part of an overall icing effects prediction strategy
Characterization of an Improved, Real-Time MEMS-Based Phase-Shifting Interferometer
We describe and present detailed performance characterizations for an enhanced version of our MEMS-Based Phase-Shifting Interferometer (MBPSI) that achieves 13 times denser motion reconstruction than our original system. We measure the noise
level to be ≤±6 nm λ for a 660 nm laser), and the frequency-resolution to be ≤ 0.03Hz for 31Hz motion captured at 300Hz.
We have successfully tracked a piezo-based actuator, driven with an arbitrary waveform composed of transients ≤10Hz
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