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Showing papers by "Vaughn College of Aeronautics and Technology published in 1962"


Journal ArticleDOI
TL;DR: In this paper, the frequency and amplification rates for a disturbance growing with respect to time are compared with those of a spatially growing wave having the same wave number, and it is shown that the frequencies are equal to a high order of approximation.
Abstract: The frequency and amplification rates for a disturbance growing with respect to time are compared with those of a spatially-growing wave having the same wave-number. For small rates of amplification it is shown that the frequencies are equal to a high order of approximation, and that the spatial growth is related to the time growth by the group velocity.

632 citations


Journal ArticleDOI
TL;DR: In this paper, a numerical solution of the partial differential equation for heat transfer in the incompressible turbulent boundary layer has been obtained for uniform ( q w ρC p u i )/√( c f 2 ) and for Prandtl numbers 0-7, 1 and 7.

15 citations



Journal ArticleDOI
TL;DR: Some of the basic relationships which are involved in the design and performance of man powered aircraft are investigated in the hope that possible ways of obtaining further improvements may emerge.
Abstract: In 1961 I assisted Mr. G. M. Lilley in writing a survey of the design and performance of man powered aircraft. Our conclusions were that man powered flight is just possible if the aircraft is carefully designed to give excellent aerodynamic characteristics, with a stiff, light structure and flown by a pilot whose power output is comparable with that of a National Amateur Cycling Champion. Such a machine would not fly more than fifteen to twenty feet above the ground and could operate only in still air conditions. The type of aircraft which emerged from the calculations was similar in general principles to those being developed currently at Hatfield and Southampton. In this lecture I propose to investigate some of the basic relationships which are involved in the hope that possible ways of obtaining further improvements may emerge. Since the conclusion of our survey was that flight was marginally possible, slight improvements might well go a long way towards making man powered flight possible.

5 citations


Journal ArticleDOI
TL;DR: In this article, a simple and rigorous theory of the perturbations of the orbits of close earth satellites can be constructed which is valid for all values of orbital eccentricity less than unity.
Abstract: It is shown that a simple and rigorous theory of the perturbations of the orbits of close earth satellites can be constructed which is valid for all values of orbital eccentricity less than unity. A vector treatment is used which leads naturally to a description of the orbital geometry in terms of the angular momentum, the direction of perigee, and the eccentricity, from which other elements may be obtained without difficulty. The method is applied briefly to the first-order effects of the earth's oblateness, and in more detail to the effects of atmospheric resistance. Certain integrals occurring in the theory of atmospheric resistance are evaluated as asymptotic series whose first two terms are sufficient for determining the perturbations to high accuracy. The motion of a close satellite of the earth departs from that of a Keplerian elliptical orbit primarily as the result of perturbing forces caused by the oblateness of the earth and the presence of the earth's atmosphere. There are also secondary perturbing forces caused by the gravitational attractions of the sun and the moon, and by solar radiation pressure, but these are small compared with the primary perturbations, except possibly in the case of low-density balloon satellites for which radiation pressures may be important, provided that the satellite does not move too far away from the earth. These perturbing forces are sufficiently small compared with the central gravitational field to allow the use of series-expansion or iteration methods for the calculation of the perturbed motions, and, further, for most satellites launched to date, the orbital eccentricities have been small enough to allow the theoretical predictions of the motions to be based on series expansions in powers of the eccentricity. The resulting analysis has usually been somewhat complicated, and it is the purpose of the present paper to show that a simplified and rigorous theory of these motions can be developed which does not depend upon the eccentricity being small. The method depends on the possibility of choosing a mean Keplerian orbit whose elements vary slowly with time, the actual orbital motion being oscillatory about this mean orbit, with period approximately equal to the orbital period. The applications in this paper are limited to the determination of the first-order variations of the mean orbit that are caused by the earth's oblateness and atmospheric resistance, but the actual motion is not difficult to obtain. The extension to second-order perturbations is easy in principle, but the algebra is much heavier than that for the first-order solution. For conciseness, the analysis is in vector form, and this leads naturally to a somewhat unconventional description of the orbital geometry in terms of the angular momentum, the direction of perigee, and the eccentricity as elements, from which the more usual sets of elements can be obtained without difficulty. The expressions found for the rates of change of the angular momentum and of the direction of [ 130 ]

3 citations


Journal ArticleDOI
01 Sep 1962-Nature
TL;DR: In this paper, the authors used a simple electrical device to maintain a constancy of torque (within 1 part in 5 × 103) as the disk rotates during creep, recorded continuously by a photoelectric follower and associated recorder (Graphi-spot) which traces the movement of a spot of light reflected from a mirror mounted on the shaft of the torque disk.
Abstract: EXPERIMENTS have been conducted on thin-walled tubes of an aluminium–magnesium alloy (3.08 per cent magnesium, 0.3 iron, 0.44 manganese, 0.18 silicon) under conditions of simple shear. Two tubes aligned on a common axis are used for each test, the torque being applied through a disk connected to both tubes. The assembly is mounted in a thermostatically controlled enclosure, and to avoid any possible errors due to inertial effects associated with the dynamic stress component, the torque is applied through a spring system. A simple electrical device is used to maintain a constancy of torque (within 1 part in 5 × 103) as the disk rotates during creep. The creep curves are recorded continuously by a photoelectric follower and associated recorder (a ‘Graphi-spot’) which traces the movement of a spot of light reflected from a mirror mounted on the shaft of the torque disk.

3 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of compressibility, temperature-jump and gaseous adsorption were considered in an attempt to predict the temperature-time history at the interface between a gas and a solid when both the temperature and the pressure of the gas are suddenly changed.
Abstract: The effects of compressibility, temperature-jump and gaseous adsorption are considered in an attempt to predict the temperature-time history at the interface between a gas and a solid when both the temperature and the pressure of the gas are suddenly changed. It appears that temperature-jump will be the dominant effect, with adsorption contributing significantly in some circumstances. Compressibility is of minor importance during practically-resolvable time intervals. Some experimental evidence which gives tentative support to the results of the analysis is commented upon.

2 citations