# Outlet

The Outlet lets water flow downstream with a prescribed flow rate. It is similar to the Pump, except that water only flows down, by gravity.

When PID controlled, the Outlet must point towards the controlled Basin in terms of edges.

# 1 Tables

## 1.1 Static

column | type | unit | restriction |
---|---|---|---|

node_id | Int32 | - | sorted |

control_state | String | - | (optional) sorted per node_id |

active | Bool | - | (optional, default true) |

flow_rate | Float64 | $^3/$ | non-negative |

min_flow_rate | Float64 | $^3/$ | (optional, default 0.0) |

max_flow_rate | Float64 | $^3/$ | (optional) |

min_upstream_level | Float64 | \(\text{m}\) | (optional) |

max_downstream_level | Float64 | \(\text{m}\) | (optional) |

# 2 Equations

The Outlet is very similar to the Pump, but it has an extra reduction factor for physical constraints:

\[ Q = \mathrm{clamp}(\phi Q_\text{set}, Q_{\min}, Q_{\max}) \]

- \(Q\) is the realized Outlet flow rate.
- \(Q_\text{set}\) is the Outlet’s target
`flow_rate`

. - \(Q_{\min}\) and \(Q_{\max}\) are the Outlet
`min_flow_rate`

and`max_flow_rate`

. - \(\phi\) is the reduction factor, which smoothly reduces flow based on all of these criteria:
- The upstream volume is below \(10 m^3\).
- The upstream level is less than \(0.02 m\) above the downstream level.
- The upstream level is below
`min_upstream_level`

+ \(0.02 m\) - The downstream level is above
`max_downstream_level`

- \(0.02 m\)