An analytical study is presented of the longitudinal long-period dynamics of an aerospace craft in a nearly circular orbit, with a thrust law depending arbitrarily on the speed and altitude. A plane of engine possibilities is first defined, with points corresponding to propulsion systems having prescribed thrust slopes with respect to speed and altitude. Approximate expressions for the characteristic roots and times are obtained by first identifying a small quantity in the coefficients of the characteristic equation, and then expanding in a perturbation series about the origin of the plane of engine possibilities, for which the solution is always known. These expressions agree very well with the exact solutions over a wide range of altitudes and thrust laws. The period of the oscillatory translational mode (phugoid) is found to be independent to first order of the thrust law, generalizing results found by previous investigators for specific thrust laws. The results apply to the speed range from hypersonic to orbital.
Thrust law effects on the long-period modes of aerospace craft
AIAA Atmospheric Flight Mechanics Conference ; 1989 ; Boston, MA, United States
01.01.1989
Aufsatz (Konferenz)
Keine Angabe
Englisch
Longitudinal long-period dynamics of aerospace craft
AIAA | 1988
|Longitudinal long-period dynamics of aerospace craft
NTRS | 1988
|NTRS | 1973
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