Aircraft vibration and flutter

Abstract

"The paper outlines the theoretical and experimental procedure one has to adopt for flutter prevention during the various stages (project, design and prototype) of the development of modern aircraft. With the advent of high speed, the aerodynamic coefficients have to be calculated with due regards to the effects of compressibility, finite aspect ratio of the lifting surfaces, sweep back and other peculiar shapes of the wings. The use of thin, small aspect ratio with external masses, necessitates the computation of higher frequency modes of vibration. Single degree of freedom flutter and the effect of control surface non-linearities has also become very important. Thus, it is shown how the availability of high speed computing machines, improved experimental technique for model and full scale testing has not kept pace with the uncertainties associated with the transonic speeds, low aspect ratio and the high frequency modes. Cross-checking of theoretical and experimental results at every stage seem to be the only answer."