Abstract

One of the many outstanding achievements of G I Taylor was the discovery of relatively simple statistical laws that apply to highly complex turbulent flows. The emergence of simple laws from complexity is well known in other branches of physics, for example the emergence of the laws of heat conduction from molecular dynamics. Complexity can also arise at large scales, and the structural vibration of an aircraft or a car can be a surprisingly difficult phenomenon to analyse, partly because millions of degrees of freedom may be involved, and partly because the vibration can be extremely sensitive to small changes or imperfections in the system. In this talk it is shown that the prediction of vibration levels can be much simplified by the derivation and exploitation of emergent laws, analogous to some extent to the heat conduction equations, but with an added statistical aspect, as in turbulent flow. The emergent laws are discussed and their application to the design of aerospace, marine, and automotive structures is described. As an aside it will be shown that the same emergent theory can be applied to a range of problems involving electromagnetic fields.