4,031 research outputs found
The pressure distribution over a semicircular wing tip on an airplane in flight
This note presents the results of flight pressure distribution tests on the right upper wing panel of a Douglas M-3 airplane equipped with a semicircular wing tip. The results are given in tables and curves in such form that the load distribution for any force coefficient within the usual range encountered in flight may easily be determined
Wide-Field Imaging from Space of Early-Type Galaxies and Their Globular Clusters
Wide-field imaging from space will reveal a wealth of information about the
globular cluster systems of any galaxies in the local universe that are
observed by such a mission. Individual globular clusters around galaxies in the
local universe have compact sizes that are ideal for the excellent spatial
resolution afforded by space-based imaging, while systems of these globular
clusters have large spatial extent that can only be fully explored by
wide-field imaging. One example of the science return from such a study is the
determination of the major formation epoch(s) of galaxies from the ages of
their globular clusters determined via their optical to near-infrared colors. A
second example is determining the sites of metal-poor globular cluster
formation from their cosmological bias, which constrains the formation of
structures early in the universe.Comment: To appear in the conference proceedings of "Wide Field Imaging from
Space" published in New Astronomy Reviews, eds. T. McKay, A. Fruchter, & E.
Linde
The pressure distribution over a modified elliptical wing tip on a biplane in flight
This note presents the results of flight pressure-distribution tests on the right upper wing panel of a Douglas M-3 airplane equipped with a modified elliptical tip having a slight amount of washout. The results are given in tables and curves in such form that the load distribution for any normal force coefficient within the usual range encountered in flight may be determined
Blood flow dynamics in patient specific arterial network in head and neck
This paper shows a steady simulation of blood flow in the major head and neck arteries as if they
had rigid walls, using patient specific geometry and CFD software FLUENT
R . The Artery geometry
is obtained by CT–scan segmentation with the commercial software ScanIPTM. A cause and
effect study with various Reynolds numbers, viscous models and blood fluid models is provided.
Mesh independence is achieved through wall y+ and pressure gradient adaption. It was found, that
a Newtonian fluid model is not appropriate for all geometry parts, therefore the non–Newtonian
properties of blood are required for small vessel diameters and low Reynolds numbers. The k–!
turbulence model is suitable for the whole Reynolds numbe
The Globular Cluster System of the Spiral Galaxy NGC7814
We present the results of a wide-field photometric study of the globular
cluster (GC) system of the edge-on Sab spiral NGC7814. This is the first spiral
to be fully analyzed from our survey of the GC systems of a large sample of
galaxies beyond the Local Group. NGC7814 is of particular interest because a
previous study estimated that it has 500-1000 GCs, giving it the largest
specific frequency (S_N) known for a spiral. Understanding this galaxy's GC
system is important in terms of our understanding of the GC populations of
spirals in general and has implications for the formation of massive galaxies.
We observed the galaxy in BVR filters with the WIYN 3.5-m telescope, and used
image classification and three-color photometry to select GC candidates. We
also analyzed archival HST WFPC2 images of NGC7814, both to help quantify the
contamination level of the WIYN GC candidate list and to detect GCs in the
inner part of the galaxy halo. Combining HST data with high-quality
ground-based images allows us to trace the entire radial extent of this
galaxy's GC system and determine the total number of GCs directly through
observation. We find that rather than being an especially high-S_N spiral,
NGC7814 has <200 GCs and S_N ~ 1, making it comparable to the two most
well-studied spirals, the Milky Way and M31. We explore the implications of
these results for models of the formation of galaxies and their GC systems. The
initial results from our survey suggest that the GC systems of typical
ellipticals can be accounted for by the merger of two or more spirals, but that
for highly-luminous ellipticals, additional physical processes may be needed.Comment: 28 pages, incl. 4 figures; accepted for publication in The
Astronomical Journal, November 2003 issu
The pressure distribution over a square wing tip on a biplane in flight
This note presents the results obtained in pressure distribution tests on the right upper panel of a Douglas M-3 airplane in flight. These tests are a part of an extensive investigation on the effect of changes in tip shape on the load distribution
Preliminary Study of Applied Load Factors in Bumpy Air
Theoretical relations involved in the study are reviewed to furnish a basis upon which experimental data can be properly analyzed. The structure of the atmosphere in relation to the load-factor problem is briefly discussed, and the acceleration data obtained on a number of flights with various airplanes are presented and analyzed to the extent that the results are applicable to n=any airplane
Discharge coefficients for thick-plate orifices
Investigation enables more accurate prediction of coolant flows within internally cooled turbine blades and vanes. The data is applicable for predicting flows in complex flow passages
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