| 1. |
- Luckrin, J. M., et al.
(författare)
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A synthesis of hybrid RANS/LES CFD results for F-16XL aircraft aerodynamics
- 2015
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Ingår i: 33rd AIAA Applied Aerodynamics Conference. - Reston, Virginia : American Institute of Aeronautics and Astronautics (AIAA). - 9781624103636
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Konferensbidrag (refereegranskat)abstract
- A synthesis is presented of recent numerical predictions for the F-16XL aircraft flow fields and aerodynamics. The computational results were all performed with hybrid RANS/LES formulations, with an emphasis on unsteady flows and subsequent aerodynamics, and results from five computational methods are included. The work was focused on one particular low-speed, high angle-of-attack flight test condition, and comparisons against flight-test data are included. This work represents the third coordinated effort using the F-16XL aircraft, and a unique flight-test data set, to advance our knowledge of slender airframe aerodynamics as well as our capability for predicting these aerodynamics with advanced CFD formulations. The prior efforts were identified as Cranked Arrow Wing Aerodynamics Project International, with the acronyms CAWAPI and CAWAPI-2.
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| 2. |
- Tomac, Maximilian, et al.
(författare)
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Unsteady aero-loads from vortices shed on A320 landing gear door : CFD compared to flight tests
- 2016
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Ingår i: 54th AIAA Aerospace Sciences Meeting. - Reston, Virginia : American Institute of Aeronautics and Astronautics. - 9781624103933
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Konferensbidrag (refereegranskat)abstract
- AFLoNext is a project of four years duration, funded by the European Commission within the Seventh Framework Programme. The project’s main objectives are proving and maturing highly promising flow control and noise reduction technologies for novel aircraft configurations, to achieve a big step forward towards improved aircraft performance and thus reducing the environmental footprint. The project consortium is composed by 40 European partners from 15 countries. One of the six technology streams, which are forming the scientific concept of AFLoNext, is concerned with the mitigation and control of vibrations in the undercarriage area during take-off and landing. Structural components in the vicinity of the landing gears, e.g. undercarriage housing walls, struts or landing gear doors, are often subject to significant dynamic loading. These loads originate from fluctuating aerodynamic pressures and resulting structural vibrations. Unsteady pressures on structural parts are caused by highly fluctuating and complex aerodynamic flow behavior under the fuselage. The paper describes the CFD approach employed to predict such dynamic loads and presents some preliminary results that have been computed with hybrid RANS-LES models and the Lattice Bolzmann method. Several vibration control devices have been proposed and are discussed in the paper. Some of these devices will be installed in the near future on the DLR Airbus 320 ATRA (Advanced Technology Research Aircraft) to perform flight tests to and to measure dynamic loads.
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| 3. |
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| 4. |
- Luckring, James M., et al.
(författare)
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Synthesis of Hybrid Computational Fluid Dynamics Results for F-16XL Aircraft Aerodynamics
- 2017
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Ingår i: Journal of Aircraft. - 0021-8669 .- 1533-3868. ; 54:6, s. 2100-2114
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Tidskriftsartikel (refereegranskat)abstract
- A synthesis is presented of recent numerical predictions for the F-16XL aircraft flowfields and aerodynamics. The computational analyses were all performed with hybrid Reynolds-averaged Navier-Stokes/large-eddy simulation formulations, with an emphasis on unsteady flows and associated aerodynamics, and results from five computational methods are included. The work focused on one particular low-speed high angle-of-attack flight-test condition, and comparisons against flight-test data are included. This work represents the third coordinated effort using the F-16XL aircraft, and a unique flight-test dataset, to advance the knowledge of slender airframe aerodynamics as well as the capability for predicting these aerodynamics with advanced computational fluid dynamics formulations. The prior efforts were identified as the Cranked-Arrow Wing Aerodynamics Project International.
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| 5. |
- Quintero, E M, et al.
(författare)
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Glial cell line-derived neurotrophic factor is essential for neuronal survival in the locus coeruleus-hippocampal noradrenergic pathway.
- 2004
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Ingår i: Neuroscience. - : Elsevier BV. - 0306-4522. ; 124:1, s. 137-46
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Tidskriftsartikel (refereegranskat)abstract
- It has been shown that the noradrenergic (NE) locus coeruleus (LC)-hippocampal pathway plays an important role in learning and memory processing, and that the development of this transmitter pathway is influenced by neurotrophic factors. Although some of these factors have been discovered, the regulatory mechanisms for this developmental event have not been fully elucidated. Glial cell line-derived neurotrophic factor (GDNF) is a potent neurotrophic factor influencing LC-NE neurons. We have utilized a GDNF knockout animal model to explore its function on the LC-NE transmitter system during development, particularly with respect to target innervation. By transplanting various combinations of brainstem (including LC) and hippocampal tissues from wildtype or GDNF knockout fetuses into the brains of adult wildtype mice, we demonstrate that normal postnatal development of brainstem LC-NE neurons is disrupted as a result of the GDNF null mutation. Tyrosine hydroxylase immunohistochemistry revealed that brainstem grafts had markedly reduced number and size of LC neurons in transplants from knockout fetuses. NE fiber innervation into the hippocampal co-transplant from an adjacent brainstem graft was also influenced by the presence of GDNF, with a significantly more robust innervation observed in transplants from wildtype fetuses. The most successful LC/hippocampal co-grafts were generated from fetuses expressing the wildtype GDNF background, whereas the most severely affected transplants were derived from double transplants from null-mutated fetuses. Our data suggest that development of the NE LC-hippocampal pathway is dependent on the presence of GDNF, most likely through a target-derived neurotrophic function.
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| 10. |
- Lorentzon, Mattias, 1970, et al.
(författare)
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Habrec1, a novel serine/threonine kinase TGF-beta type I-like receptor, has a specific cellular expression suggesting function in the developing organism and adult brain
- 1996
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Ingår i: Exp Neurol. - : Elsevier BV. - 0014-4886 .- 0014-4886. ; 142:2, s. 351-60
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Tidskriftsartikel (refereegranskat)abstract
- Members of the TGF-beta superfamily signal through a dual receptor system consisting of a type II receptor protein kinase that binds the ligand, after which this complex associates with a type I receptor to mediate intracellular signaling. In mammals, six type I and five type II receptors mediating responses to different TGF-beta family members have been identified to date. Using primers from conserved regions of the protein kinase domain of the serine/threonine kinase receptors in a low-stringency polymerase chain reaction-based screening procedure, and deselecting known receptors with colony hybridization, we now report cloning a novel receptor member. The novel receptor was found in a cDNA library prepared from the habenular nucleus area and was designated Habrec1. Although only a partial sequence is available, it fits the criteria for a TGF-beta type I serine/threonine kinase receptor. In situ hybridization of Habrec1 reveals mRNA expression in several distinct areas of the developing central nervous system, including cortex cerebri, cerebellum, hippocampus, striatum, and thalamic nuclei. Expression is also seen in the anterior pituitary. In the periphery, strong expression prenatally includes brown fat, the gastrointestinal tract, liver, pancreas, thymus, and nasal cavity epithelium. In the adult brain Habrec1 mRNA is prominently found in cerebellum, cortex cerebri, and striatum, but at lower levels in several additional areas. We conclude that Habrec1 is a member of the TGF-beta type I receptor family with expression patterns in the developing animal, suggesting specific functions in and outside the nervous system, and in the adult CNS, suggesting roles in both cortical and subcortical brain circuitry.
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