🌊 Continuous Grade Inlets 🌊
Continuous grade inlets play a pivotal role in managing water flow. They work based on the inlet's efficiency in capturing the flow.
🔶 Continuous Grate Inlet 🔶
The formulas used in InfoWorks ICM 🖥️ for understanding flow interception are inspired by the equations from the reputable FHWA HEC 22 Urban Drainage Manual 📘.
To get started, you'll need these inlet parameters on the Node Property Sheet:
- Cross slope 📐
- Grate width 📏
- Grate length 🔍
- Velocity where splash-over occurs first 🌊
- Clogging factor (representing the percentage decrease in flow capacity of the grate) 🍂.
If the inlet gets drowned or experiences reverse flow, then the orifice equation from the Sag Grate Inlet kicks in. The open area is perceived as 0.8LW, a standard reduction across many inlet types.
📌 Efficiency is expressed using:
(Equation 1)
Where:
- Rf = Frontal flow ratio 🌊
- Rs = Side flow ratio 🌊
- E0 = Frontal flow proportion 🌊
The formulas for Rf, Rs, and E0 are provided (Equations 2, 3, & 4).
🔷 Continuous Curb-opening Inlet 🔷
For this inlet type, the equations employed by InfoWorks ICM are also based on the FHWA HEC 22 Urban Drainage Manual 📘.
Parameters required on the Node Property Sheet include:
- Curb opening length 📏
- Cross slope 📐
- For depressed inlets, gutter depression and lateral width of gutter depression are essential 🌊.
When dealing with drowned-forward or reverse flow, either drowned weir or orifice flow mechanics are used, similar to the Sag Curb-opening inlet. The nominal opening height is taken as 100mm.
📌 Efficiency is expressed as:
(Equation 6)
Where:
- L = Curb opening length 📏
- LT = Required curb opening length for total interception 🌊
The formula for LT is given by Equation 7. If you're dealing with a depressed curb-opening inlet, then replace Sx with Se, which is the equivalent cross slope calculated using Equation 8.
Remember, InfoWorks ICM's equations and parameters ensure optimal water flow management, making our urban spaces safer and more efficient! 💧🌟
