scholarly journals Vortex pairs on a triaxial ellipsoid and Kimura's conjecture

2018 ◽  
Vol 10 (2) ◽  
pp. 189-208 ◽  
Author(s):  
Adriano Regis Rodrigues ◽  
◽  
César Castilho ◽  
Jair Koiller ◽  
◽  
...  
2019 ◽  
Vol 24 (1) ◽  
pp. 61-79
Author(s):  
Jair Koiller ◽  
César Castilho ◽  
Adriano Regis Rodrigues

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.


2003 ◽  
Vol 15 (7) ◽  
pp. 1861-1874 ◽  
Author(s):  
Denis Sipp ◽  
Laurent Jacquin
Keyword(s):  

2013 ◽  
Vol 50 (1) ◽  
pp. 26-31 ◽  
Author(s):  
Stephen A. Kissin ◽  
Neil D. MacRae ◽  
Reid R. Keays

A. 3.58 kg pallasite meteorite was found in April 2001, near the mouth of the Saugeen River on Lake Huron (44°30.385′N, 81°22.330′W) by Carl Young of London, Ontario. The specimen is in the form of an irregular triaxial ellipsoid approximately 6.8 cm × 13.4 cm × 18.1 cm. Olivine crystals are visible on the smooth exterior surface which has a thin rind of oxidized iron. The sectioned interior contains olivine crystals with a considerable range in sizes up to approximately 2.5 cm diameter. Larger crystals have angular outlines and some are fractured, although corners and small grains are rounded. Apart from the kamacite and taenite of the metal phase, only small amounts of schreibersite and troilite are present. Analysis of the metal phase by instrumental neutron activation analysis (INAA) yielded Ni 97.4 mg/g, Ga 17.2 μg/g, Ge 77.8 μg/g, Ir 0.137 μg/g, and Au 2.12 μg/g. These values lie within the defined ranges for main group pallasites, except that Ge is ca. 20% higher. Analysis by inductively coupled plasma – mass spectrometry (ICP–MS) yielded Ir 0.0755 μg/g and Au 0.937 μg/g, differences attributed to difference in the mass and heterogeneity of the material analyzed. Olivines were found to have a mean composition of fayalite (Fa) 12.30, within the range of compositions for main group pallasites. Although the Hopewell Mounds of south-central Ohio contain fragments of the Brenham (Kansas) pallasite that were transported there by pre-contact people and are in the same region as the Southampton meteorite find, the apparent glacial transport of the newly found pallasite together with its compositional and textural differences indicate that it is a unique meteorite and the third pallasite found in Canada. The pallasite is named after the community of Southampton in which it was found.


Author(s):  
C. R. Hedlund ◽  
P. M. Ligrani ◽  
H.-K. Moon ◽  
B. Glezer

Heat transfer and fluid mechanics results are given for a swirl chamber whose geometry models an internal passage used to cool the leading edge of a turbine blade. The Reynolds numbers investigated, based on inlet duct characteristics, include values which are the same as in the application (18000–19400). The ratio of absolute air temperature between the inlet and wall of the swirl chamber ranges from 0.62 to 0.86 for the heat transfer measurements. Spatial variations of surface Nusselt numbers along swirl chamber surfaces are measured using infrared thermography in conjunction with thermocouples, energy balances, digital image processing, and in situ calibration procedures. The structure and streamwise development of arrays of Görtler vortex pairs, which develop along concave surfaces, are apparent from flow visualizations. Overall swirl chamber structure is also described from time-averaged surveys of the circumferential component of velocity, total pressure, static pressure, and the circumferential component of vorticity. Important variations of surface Nusselt numbers and time-averaged flow characteristics are present due to arrays of Görtler vortex pairs, especially near each of the two inlets, where Nusselt numbers are highest. Nusselt numbers then decrease and become more spatially uniform along the interior surface of the chamber as the flows advect away from each inlet.


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