Flow routing within a conduit link in SWMM is governed by the conservation of mass and momentum equations for gradually varied, unsteady flow (i.e., the Saint Venant flow equations). The SWMM user has a choice on the level of sophistication … Read the rest
The dialog box for the SCS peak discharge method is shown below.
· Unit System – English or SI unit.
· Solving Target – Peak discharge or time of concentration.
· Equations – Rational method or … Read the rest
Energy Relation for Closed Conduit Flow
Conservation of energy involves a balance in total energy, expressed as head, between any upstream point of flow and a corresponding downstream point, including head losses caused by friction and the viscous dissipation of turbulence at bends and other appurtenances (i.e., form losses or … Read the rest
Gutter Flow
Gutters are the sections of roadway that run adjacent to the curb. Their purpose is to collect and convey surface runoff to drainage inlets and in turn to underground storm sewers. The corresponding spread of water onto the pavement, or top width of flow measured perpendicular to the … Read the rest
Pump Characteristic Curve
Pump Characteristic Curve
Pump characteristic curves are usually presented graphically describing the relationship between pump head, hp, and the flow rate, Q using either an exponential equation or 3-point quadratic form. The exponential pump characteristic curve is given as
where hc = the pump cutoff head … Read the rest
Inertia of Pumps and Motors
The combined inertia of pumps and motors driving them, including the connecting shafts and couplings, is required for transient analysis associated with the starting and stopping of pumps. The equations provided below are intended to be used as an initial guide to the inertia values … Read the rest
3.4 Gradually Varied Flow
Discussions in the previous sections have focused on uniform flow hydraulics where flow depth y and flow velocity V remain constant along the channel. In this section, we consider gradually varied flow, which is a form of steady nonuniform flow characterized by gradual variations in flow … Read the rest
2.3.1 Flow Calculator (Simple in Innovyze H2OCalc)
The Flow Calculator category performs hydraulic calculations for the following elements: Circular Channel, Rectangular Channel, Triangular Channel, Trapezoidal Channel, Irregular Channel, and Pressurized Pipe.
Circular Channel
The circular channel dialog box is shown below.
Input for circular channel:
3.14 Water Hammer
Surge analysis is important to estimate the worst-case events in the Water Distribution Systems (WDS). Transient regimes in WDS are inevitable and will normally occur as a result of action at pump stations and control valves. Regions that are particularly susceptible to transients are high elevation areas, … Read the rest
3.3 Moody Friction Factor Calculator
Darcy-Weisbach friction factor, f, can be evaluated in terms of equivalent sand grain roughness, e, and Reynolds number, Re. Reynolds number is a dimensionless ratio of inertial forces to viscous forces acting on flow and is defined for any cross-sectional shape as
For … Read the rest