Transient airflow in building drainage systems / John Swaffield

1 Building drainage and vent systems, a traditional building service requiring an engineering analysis makeover? --
1.1 The requirement for drainage and vent systems --
1.2 Basic operational mechanisms within drainage and vent systems --
1.3 Historic development of building drainage and vent systems --
1.4 Air entrainment, annular flow and terminal velocity --
1.5 Assessment of system water flows --
fixture and discharge unit approaches --
1.6 Definition of airflow as unsteady, relationship to pressure surge theory --
1.7 Time line for analysis techniques --
1.8 Concluding remarks --
2 Pressure transient propagation in building drainage and vent systems --
2.1 Development of pressure transient theory --
2.2 Building drainage and vent system pressure transient propagation --
2.3 Wave speed --
2.4 Development of the equations of continuity and momentum, leading to the Joukowsky equation --
2.5 Transients generated by changes in flow velocity --
2.6 Terminal system boundary condition reflections --
2.7 Internal system boundary condition reflections --
2.8 Simplification due to constant wave speed --
2.9 Application to a building drainage and vent system vertical stack --
2.10 Effect of variable wave speed on junction reflection and transmission coefficients --
2.11 Trapped transient in branch --
2.12 Principle of superposition of pressure waves --
2.13 Trap seal reflection coefficient --
2.14 Concluding remarks --
3 Mathematical basis for the simulation of low amplitude air pressure transients in vent systems --
3.1 Development of the general St Venant equations of continuity and momentum --
3.2 Derivation of the St Venant unsteady flow equations in the special case of low amplitude air pressure transient propagation in building drainage and vent systems --
3.3 Application of the Method of Characteristics to transform the St Venant equations into a total derivative form --
3.4 Frictional representation within the St Venant equations --
3.5 Boundary condition modelling --
3.6 Transient driving functions --
3.7 Traction forces acting on the air core within a building drainage and vent system --
3.8 Concluding remarks --
4 Simulation of the basic mechanisms of low amplitude air pressure transient propagation --
AIRNET applications --
4.1 Drainage and vent system design and the simulation of the pressure regime in each common system type in response to multiple appliance discharge --
4.2 Dependence of entrained airflow on appliance discharge, inflow position and restrictions to airflow entry due to blocked vent terminations or defective traps --
4.3 Simulation of transients imposed on the drainage network by external changes in conditions --
4.4 The simulation of stackbase surcharge --
4.5 Modelling the effect of a surcharge in a stack offset --
4.6 Frictional representation as affected by the rate of change of the local flow conditions --
4.7 Discharging branch boundary condition and the effect of falling solids --
4.8 Concluding remarks --
5 Pressure surge as a source of system failure, leading to the development of control and suppression strategies --
5.1 Consequence of transient propagation --
5.2 Control of transients --
5.3 Applications in building utility systems --
5.4 Applications within building drainage and vent systems --
5.5 Development of a low amplitude positive transient attenuator --
5.6 Active and passive pressure transient.