chapter  8
4 Pages


This book has sought to set out the fundamental engineering science relating to the prediction and simulation of building drainage free surface flows, based on nearly 40 years of research and investigation. This has led to a comprehensive approach to designing building drainage systems, and understanding the ‘why’ as well as the ‘how’ of system design. The fundamental mathematics for the description of free surface waves has been available since the nineteenth century when the French elasticity theorist Adhémar Jean Claude Barré de Saint-Venant, commonly known as St Venant, developed his 1-D equations to model open channel flow. These 1-D equations are easier to solve than the much more complex ‘shallow water equations’ and have been shown (see Chapter 3) to be wholly appropriate for free surface wave modelling in partially filled building drainage pipes (Waterwise 2014).