© 1952 by Oxford University Press
NOTE ON A GENERALIZATION OF RAYLEIGH'S PRINCIPLE
( Department of Aeronautics and Fluid Mechanics, The University Glasgow )
Any root
of the characteristic equation of a set of n linear ordinary differential equations with constant coefficients and of order m is also a root of an equation of degree m whose coefficients are quadratic forms in the modal coordinates corresponding to
. It is shown that, when the matrices of the coefficients of each order in the differential equations are symmetric, the root
of the equation of mth degree is stationary for small deviations of the modal coordinates from their true ratios for the mode considered.