Hostname: page-component-848d4c4894-jbqgn Total loading time: 0 Render date: 2024-07-03T12:41:47.166Z Has data issue: false hasContentIssue false

Forces, moments, and added masses for Rankine bodies

Published online by Cambridge University Press:  28 March 2006

L. Landweber
Affiliation:
Iowa Institute of Hydraulic Research, State University of Iowa
C. S. Yih
Affiliation:
Iowa Institute of Hydraulic Research, State University of Iowa

Abstract

The dynamical theory of the motion of a body through an inviscid and incompressible fluid has yielded three relations: a first, due to Kirchhoff, which expresses the force and moment acting on the body in terms of added masses; a second, initiated by Taylor, which expresses added masses in terms of singularities within the bòdy; and a third, initiated by Lagally, which expresses the forces and moments in terms of these singularities. The present investigation is concerned with generalizations of the Taylor and Lagally theorems to include unsteady flow and arbitrary translational and rotational motion of the body, to present new and simple derivations of these theorems, and to compare the Kirchhoff and Lagally methods for obtaining forces and moments. In contrast with previous generalizations, the Taylor theorem is derived when other boundaries are present; for the added-mass coefficients due to rotation alone, for which no relations were known, it is shown that these relations do not exist in general, although approximate ones are found for elongated bodies. The derivation of the Lagally theorem leads to new terms, compact expressions for the force and moment, and the complete expressions of the forces and moments in terms of singularities for elongated bodies.

Type
Research Article
Copyright
© 1956 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Birkhoff, G. 1953 Hydrodynamics. Princeton University Press.
Cummins, W. E. 1953 The forces and moments acting on a body moving in an arbitrary potential stream. David Taylor Model Basin, Rep. no. 708.Google Scholar
Lagally, M. 1922 Berechnung der Kräfte und Momente die stroömende Flüssigkeiten auf ihre Begrenzung ausüben. Z. angew. Math. Mech. 2, 409.Google Scholar
Lamb, H. 1932 Hydrodynamics, 6th Ed. Cambridge University Press.
Landweber, L. 1956 On a generalization of Taylor's virtual mass relation for Rankine bodies. Quart. Appl. Math. 14, 51.Google Scholar
Taylor, G. I. 1928 The energy of a body moving in an infinite fluid, with an application to airships. Proc. Roy. Soc. A, 120, 13.Google Scholar