Mathematical Models in WaterModels

Notation for Sets

A water distribution network is represented by a directed graph $\mathcal{G} := (\mathcal{N}, \mathcal{L})$, where $\mathcal{N}$ is the set of nodes and $\mathcal{L}$ is the set of arcs (conventionally "links," e.g., pipes and valves). Temporal evolution of the network is represented by a set $\mathcal{K}$, denoting the set of all time steps considered. In summary, the following sets are commonly used when defining a WaterModels problem formulation:

NotationWaterModels TranslationDescription
$\mathcal{N}$wm.ref[:nw][n][:node]nodes (to which nodal-type components are attached)
$\mathcal{K}$nw_ids(wm)time indices (multinetwork indices labeled by n)
$\mathcal{D}$wm.ref[:nw][n][:demand]demands
$\mathcal{R}$wm.ref[:nw][n][:reservoir]reservoirs
$\mathcal{T}$wm.ref[:nw][n][:tank]tanks
$\mathcal{A} \subset \mathcal{L}$wm.ref[:nw][n][:pipe]pipes
$\mathcal{P} \subset \mathcal{L}$wm.ref[:nw][n][:pump]pumps
$\mathcal{W} \subset \mathcal{L}$wm.ref[:nw][n][:regulator]regulators
$\mathcal{S} \subset \mathcal{L}$wm.ref[:nw][n][:short_pipe]short pipes
$\mathcal{V} \subset \mathcal{L}$wm.ref[:nw][n][:valve]valves

Physical Feasibility

Nodes

Demands

Reservoirs

Tanks

Pipes

Design Pipes

Pumps

Regulators

Short Pipes

Valves

Satisfaction of Flow Bounds

Satisfaction of Head Bounds

Conservation of Flow

Head Loss Relationships

Nonconvex Nonlinear Program

Mixed-integer Convex Program

Mixed-integer Linear Program