Emoji ICM InfoWork - 🌊 InfoWorks ICM 1D Hydraulic Model Equations

 

🌊 InfoWorks ICM 1D Hydraulic Model Equations:

This section covers the equations used by InfoWorks ICM for 1D hydraulic modeling in InfoWorks networks. For 2D engine equations, please refer to the Basic 2D Hydraulic Theory topic and 2D Conduits topic.

For SWMM networks hydraulic equations, please consult the SWMM Reference Manual (Hydraulics) available on the EPA website.

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🧩 Solution Model:

The solution model for conduits is chosen via the Solution model field in the associated property sheet.

Conduit Model (Full solution model):

• Representation: Conduits are depicted as links between two nodes with defined lengths.
• Boundary Condition: Between a link and a node, it can either be outfall or headloss type.
• Gradient: Determined by invert levels at both link ends.
• Cross-Sectional Shapes: Pre-defined shapes available for closed pipes and open channels.
• Hydraulic Roughness: Two values can be assigned.
• Sediment: Permanent depth can be defined, but no erosion or deposition is accounted for.
• Key Equations: Saint-Venant equations.

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Pressurised Pipe Model:

Use this model for specific pipes such as rising mains or inverted siphons.

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Force Main Model:

An advanced feature representing certain pressurised systems. Consult Innovyze Support for details.

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Permeable Solution Model:

Used for specific pipes like permeable pavements.

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Finite Volume Solution Model:

• Use Case: Specifically for complex trans-critical flow scenarios, like hydraulic jumps within a conduit.
• Solver: Built into the existing solution scheme.

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Solver:

The Newton-Raphson method is utilized to ensure the stability of calculations. The method is characterized by potentially quadratic convergence. Non-linear effects might adjust the timestep.

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Modelling Features:

• Supercritical Conditions: Likely in conduits with a slope greater than the critical slope.
• Low Depths in Conduit: At low depths, the same discharge can occur at two varied downstream depths.

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For a more comprehensive study, ensure you delve deeper into each section to understand the nuances and details of the hydraulic theory. Proper understanding will lead to accurate modeling and simulation results. 📝🌊🌐.

SWMM5 CN Code for Infiltration Rate

 📌 Purpose of the Code:

This code 🖥 calculates the infiltration rate using the Curve Number method for a specific patch of land, known as a subcatchment. 🌍💧

📂 Inputs:

• infil: 📦 A pointer to the Curve Number infiltration object.
• tstep: ⏳ The runoff time step in seconds.
• irate: ☔ The rainfall rate in feet per second.
• depth: 🌊 The depth of runon + ponded water in feet.

📂 Output:

• Sends back 🚀 the infiltration rate in feet per second.

🔍 Detailed Breakdown:

1️⃣ Initial Setup:

• A few local variables like F1 and f1 are initialized. 📊
• fa gives us the max available infiltration rate, considering both the rainfall 🌧 and the effect of ponded water over time. ⌛

2️⃣ Rainfall Case (irate > ZERO):

• New rainfall? 🌦 Reset values! Resets the cumulative precipitation (P), infiltration (F), rate (f), and storage depth (Se).
• Update the total rainfall amount 📈.
• Compute potential new cumulative infiltration 📉.
• Determine the infiltration rate 💧.

3️⃣ No Rainfall Case (else):

• If water's still around 🌊 (but no new rain), the infiltration rate sticks to the last known value but within storage limits.
• If everything's dry 🌵, the time since the last rain (T) gets an update.

4️⃣ Infiltration Update:

• Got some infiltration? 💦 Limit the rate considering the max available rate.
• Make sure the total infiltration (F) gets updated 📝.
• If there's a regeneration constant given, the infiltration capacity (S) takes a dip 📉.

5️⃣ Infiltration Capacity Regeneration:

• No infiltration? Time for the capacity (S) to regenerate 🌱, based on a given constant and the max storage.

6️⃣ Return Value:

• Update the current infiltration rate (f1) for the object and send it back! 🎉

📝 Summary: This nifty function 🖥 computes the infiltration rate in a patch of land using the Curve Number method. It dances 💃 between rainfall and no-rainfall scenarios, adjusting the infiltration capacity as needed. And voilà! It sends back the updated rate. 🌧💧🌱

There we go! A sprinkle of emojis for added flair! ✨🎉🎈 Hope it helps! 😊🌟🎈