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Posted Fri March 28, 2003 @09:46AM
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With the release of Coolit v5.0, Daat Research Corp. becomes the first CFD company to successfully incorporate embedded mesh technology within an electronics thermal management package. This pioneering approach eliminates dependence on approximate model building techniques, such as resistor networks and lumped parameter (compact) models, thereby simplifying model building while increasing model fidelity and accuracy, and delivering order of magnitude increases in calculating speed.
The software creates individual mesh systems for objects within the system using a grid setup based on the length scales and the physics of each zone. It then manages communications among the multiple zones ensuring reliable, fast and stable convergence. The entire system can be modeled in one swoop with a dramatic reduction in solution time. In a problem simulating the use of multi-zone grids, Coolit v5.0 computed the flow through four pin-fin heat sinks with a reduction in cell count from over one million to just sixty-two thousand and a savings in compute time--from over 8 hours to less than 15 minutes!.
Coolit v5.0 operates on all Windows-based platforms: Windows 95,95, NT, 2000 and XP. For further information, contact Daat Research Corp. at info@daat.com.
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| Application: Navy Successfully Simulates Effect that May Improve Low-Speed Maneuverability
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Posted Thu March 27, 2003 @11:47AM
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By Joseph Slomski and Tom Marino
Research Engineers
Naval Surface Warfare Center, Carderock Division
Bethesda, Maryland
The Naval Surface Warfare Center (NSWC) has successfully simulated the Coanda effect using computational fluid dynamics (CFD) – which may help improve low-speed maneuverability of ships and planes. The engineers demonstrated that by blowing air out of a strategically located slot in an airfoil, the rear stagnation point could be moved further aft along the trailing edge of the airfoil, thereby increasing lift. The military has worked on a number of potential applications for this effect, such as making it possible for submarines moving at low speeds to make sharp turns. The key to the advance made by the NWSC was the use of the Reynolds stress model for predicting turbulence in the jet, which the research shows is far more accurate than the more common k-epsilon models.
The Naval Surface Warfare Center is the principal Navy resource, national focal point and international leader in surface and undersea vehicle science, ship systems and related maritime technology. A major technical component of the Naval Sea Systems Command, the Division is a source of innovative technology for other national priorities such as environment, energy and transportation. The Division is responsible for research, development, test and evaluation, fleet support, and in-service engineering for surface and undersea vehicles, including hull, machinery and electrical systems, and propulsors. It conducts logistics research and development, and provides support to the Maritime Administration and the maritime industry. The technical leadership areas of the Carderock Division include materials, structures, ship protection systems, vehicle concepts, hydrodynamics, acoustic and electromagnetic signatures, environmental protection systems, and logistics.
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| Shuttle Disaster Investigators Turn to CFD for Answers |
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Posted Wed March 26, 2003 @05:19PM
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Newsday is reporting that investigators are presuming that
the shuttle sustained damage to its left wing earlier than
previously thought and that the damage was masked by changes in aerodynamics which locally increased lift, thereby compensating for
any damage.
Stephen Labbe, chief of the Applied Aeroscience and Computational Fluid Dynamics branch at Johnson Space Center, said last week that the shuttle experienced an unusual change in forces on its left wing between the shedding of two pieces of observed debris.
Despite the presumed damage, he said, the orbiter "executed a perfectly nominal roll reversal," or banking of the wings, about two minutes after the two pieces of debris were shed.
Significant damage, he said, can create "locally a very high pressure that is on the lower surface of the wing and starting to push up on the wing."
Labbe and other NASA officials told the board that wind tunnel tests and computational studies simulating various types of damage to the left wing have yet to provide a coherent explanation for all of the forces Columbia experienced before it broke apart. The teams plan to do additional studies that mimic more severe damage than originally postulated, including the loss of multiple leading edge panels rather than just one.
Investigators face a complex task with computational tools they have had to develop as they go. There are no good models, officials said, for what happens when hot gases penetrate a shuttle wing and pass through existing vents or directly attack aluminum spars and ribs.
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| Events: New Series of Web-based CFD Demonstrations
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| SGI Altix 3000 Delivers Performance and Productivity for MCAE Applications |
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| Events: ICEM CFD User Conference 2003
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