Equations of Motion in Terms of Osculating Elements

In previous papers (Prȩtka and Dybczyński, 1994; Dybczyński and Prȩtka, 1996) we presented detailed analysis of selected examples of the long-term evolution of the orbit of Oort cloud comets under the influence of the galactic disk tidal force, as well as some statistical characteristics of the simulated observable comet population. This paper presents further improvements in our Monte Carlo simulation programme which allow us to represent in a better way the real processes of production of observable comets due to galactic perturbations.In our second paper (Dybczyński and Prȩtka, 1996), following some other authors (see for example Matese and Whitman, 1989), we treated a comet as observable when its osculating perihelion distance decreased below some adopted observability limit (5 AU in our case). Limiting the investigation to the evolution of osculating elements allowed us to use very fast and efficient averaged Hamiltonian equations of motion in our simulation. However, further detailed analysis of the problem showed that the adopted observability definition was insufficient: what makes a comet observable is not its osculating perihelion distance but its true distance from the Sun, smaller than some adopted threshold value. It may happen that when the osculating perihelion distance is at its smallest, the comet is around its aphelion distance.

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Equations of motion for isolated bodies with relativistic corrections including the radiation reaction force

Symposium - International Astronomical Union ◽

10.1017/s0074180900147941 ◽

1986 ◽

Vol 114 ◽

pp. 19-34 ◽

Cited By ~ 1

Author(s):

L. P. Grishchuk ◽

S. M. Kopejkin

Keyword(s):

Equations Of Motion ◽

Reaction Force ◽

Slow Motion ◽

Major Axis ◽

Radiation Reaction ◽

Secular Change ◽

Semi Major Axis ◽

Relativistic Corrections ◽

Relativistic Mass ◽

Osculating Elements

We have derived in an explicit form the equations of motion for two spherically-symmetric non rotating bodies in the slow motion approximation. The equations include relativistic corrections of order (v/c)2, (v/c)4 and (v/c)5 to the newtonian equations of motion. It is shown that the equations depend on the only parameter characterizing each body, namely on its relativistic mass, regardless of its internal structure and degree of compactness. This means that the equations can also be applied to bodies with a strong internal gravity, such as neutron stars and black holes. It is shown that in the (v/c)2 and (v/c)4 approximations the equations can be derived from a Lagrangian. The Lagrangian is given in an exact form. The integration of the equations of motion is performed by the method of osculating elements. The formulae for secular change of the semi-major axis and eccentricity coincide precisely with the standard ones whose derivation is based on a calculation of the energy flux in the outgoing gravitational waves.

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The motion of a lunar orbiter

Symposium - International Astronomical Union ◽

10.1017/s0074180900105686 ◽

1966 ◽

Vol 25 ◽

pp. 373

Author(s):

Y. Kozai

Keyword(s):

Degrees Of Freedom ◽

Dimensional Space ◽

Artificial Satellite ◽

Equations Of Motion ◽

Triaxial Ellipsoid ◽

The Moon ◽

Secular Motion ◽

The Earth ◽

Close Satellite ◽

The Mean

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.

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On the motion of comet P/d’Arrest

International Astronomical Union Colloquium ◽

10.1017/s025292110003387x ◽

1974 ◽

Vol 22 ◽

pp. 145-148

Author(s):

W. J. Klepczynski

Keyword(s):

Equations Of Motion ◽

Variational Equations ◽

Partial Derivatives

AbstractThe differences between numerically approximated partial derivatives and partial derivatives obtained by integrating the variational equations are computed for Comet P/d’Arrest. The effect of errors in the IAU adopted system of masses, normally used in the integration of the equations of motion of comets of this type, is investigated. It is concluded that the resulting effects are negligible when compared with the observed discrepancies in the motion of this comet.

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Validation of a Belt Model for Prediction of Hub Forces from a Rolling Tire4

Tire Science and Technology ◽

10.2346/1.3130984 ◽

2009 ◽

Vol 37 (2) ◽

pp. 62-102 ◽

Cited By ~ 3

Author(s):

C. Lecomte ◽

W. R. Graham ◽

D. J. O’Boy

Keyword(s):

Internal Pressure ◽

Equations Of Motion ◽

Three Dimensional ◽

Prediction Method ◽

Analytical Models ◽

Beam Model ◽

Impedance Boundary ◽

Bending Waves ◽

Tire Rotation ◽

Three Dimensional Models

Abstract An integrated model is under development which will be able to predict the interior noise due to the vibrations of a rolling tire structurally transmitted to the hub of a vehicle. Here, the tire belt model used as part of this prediction method is first briefly presented and discussed, and it is then compared to other models available in the literature. This component will be linked to the tread blocks through normal and tangential forces and to the sidewalls through impedance boundary conditions. The tire belt is modeled as an orthotropic cylindrical ring of negligible thickness with rotational effects, internal pressure, and prestresses included. The associated equations of motion are derived by a variational approach and are investigated for both unforced and forced motions. The model supports extensional and bending waves, which are believed to be the important features to correctly predict the hub forces in the midfrequency (50–500 Hz) range of interest. The predicted waves and forced responses of a benchmark structure are compared to the predictions of several alternative analytical models: two three dimensional models that can support multiple isotropic layers, one of these models include curvature and the other one is flat; a one-dimensional beam model which does not consider axial variations; and several shell models. Finally, the effects of internal pressure, prestress, curvature, and tire rotation on free waves are discussed.

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Calculation of Dynamic Tire Forces from Aircraft Instrumentation Data

Tire Science and Technology ◽

10.2346/1.3481649 ◽

2010 ◽

Vol 38 (3) ◽

pp. 182-193 ◽

Cited By ~ 1

Author(s):

Gary E. McKay

Keyword(s):

System Performance ◽

Equations Of Motion ◽

Test Laboratory ◽

Excellent Correlation ◽

Friction Behavior ◽

Aircraft Landing ◽

Data Scatter ◽

Tire Forces ◽

Six Degree Of Freedom ◽

Tire Friction

Abstract When evaluating aircraft brake control system performance, it is difficult to overstate the importance of understanding dynamic tire forces—especially those related to tire friction behavior. As important as they are, however, these dynamic tire forces cannot be easily or reliably measured. To fill this need, an analytical approach has been developed to determine instantaneous tire forces during aircraft landing, braking and taxi operations. The approach involves using aircraft instrumentation data to determine forces (other than tire forces), moments, and accelerations acting on the aircraft. Inserting these values into the aircraft’s six degree-of-freedom equations-of-motion allows solution for the tire forces. While there are significant challenges associated with this approach, results to date have exceeded expectations in terms of fidelity, consistency, and data scatter. The results show excellent correlation to tests conducted in a tire test laboratory. And, while the results generally follow accepted tire friction theories, there are noteworthy differences.

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