ABSTRACT

While the purpose of a building drainage and vent system is to allow the rapid removal of liquid and solid waste from a building, the mechanisms inherent in system operation have been often regarded as in some way outside the application of quite standard fluid mechanics theory. While the flow conditions are accurately described as unsteady, i.e. responding to random appliance operation with time dependent discharge flow profiles, and multi-phase, i.e. the flow comprises free surface water flows, entrained airflows and intermittent solid transport, this does not imply that a theoretical base for system analysis is not available.