Browsing by Author "Ward, G. N."

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    The drag of source distributions in linearized supersonic flow
    (Cranfield College of Aeronautics, 1955-02) Ward, G. N.
    Most bodies whose wave drags in supersonic flow have been calculated by linearised theory are such that the flows can be represented by a suitable distribution of sources. The present paper extends this idea by considering the drag problem for the general class of thin and slender bodies which can be replaced by sources only. The flow due to sources is necessarily acyclic, so there can be no local cross-stream forces on such bodies, since their presence would require the introduction of vortex elements.
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    Stability of a rotating cylindrical shell partially filled with liquid
    (College of Aeronautics, 1957-03) Ward, G. N.
    The theory of the stability of a gyroscope which has a right circular cylindrical cavity partially filled with liquid has been developed by Stewartson (reference 1), who has shown that instabilities occur at and near those filling-ratios for which the frequencies of free oscillations of the liquid filling coincide with the frequencies of precession and nutation of the empty gyroscope when the mass of liquid is small compared with the mass of the empty gyroscope. Then applied to the motion of a gyrostat, Stewartson's theory shows that there is an infinite number of filling-ratios at which instability is to be expected theoretically; but, in practice, it is to be expected that the effects of viscosity in the liquid filling will damp out all but the graver modes of oscillation, and one of the objects of the present experimental investigation was to determine how many of the instabilities could be detected. Stewartson's theory also predicts the range of filling-ratios for which the gyrostat should be unstable, and a second object of the experiments was to verify these predicted ranges.