Similarity Analysis of Wave Propagation Problems

A wave is any recognizable feature of disturbance that is transferred from one part of the medium to another with a recognizable velocity of propagation. There are two main classes of wave motion that can arise in physical situations: (1) propagation of waves along the characteristics of the governing hyperbolic partial differential equation, and (2) non-characteristic wave propagation for which the wave does not move along the characteristics. In this chapter, we will discuss different aspects of similarity analysis and the role of group invariance, as they relate to wave-propagation problems.