Detailed Overview of kinwave_execute Function in SWMM5 🌊🖥️

 

Detailed Overview of kinwave_execute Function in SWMM5 🌊🖥️🔍

The kinwave_execute function in EPA SWMM5, updated in version 5.2 (Build 5.2.0), is a key component for calculating the kinematic wave flow routing in conduits. Let's dive into a detailed exploration with added emojis for clarity:

Function Prototype 📝

• Input:
  • j (link index)
  • *qinflow (inflow at current time in cubic feet per second - cfs)
  • tStep (time step in seconds)
• Output:
  • *qoutflow (outflow at current time in cfs)
• Returns: Number of iterations used
• Purpose: To determine the outflow over a time step given the flow entering a conduit using Kinematic Wave flow routing.

Flow Diagram 🌊➡️🔄

• Initial Checks:

  • Non-Conduit Link: No routing needed; *qoutflow equals *qinflow.
  • Dummy Cross-Section: No routing performed.

• Module-Level Variables Assignment:

  • pXsect: Points to the link's cross-section.
  • Qfull: Full flow capacity of the link.
  • Afull: Full area of the cross-section.
  • Beta1: Ratio of conduit's beta coefficient to Qfull.

• Normalization of Flows and Areas:

  • Previous flows (q1, q2) and inflow (qin) are normalized against Qfull.
  • Previous areas (a1, a2) are normalized against Afull.
  • Inlet area (ain) is determined based on the inflow.

• Flow and Area Checks:

  • No Flow Condition: If qin is tiny and q2 is also small, qout and aout are set to zero.
  • Solve Continuity Equation:
    • Constant factors (dxdt, dq, C1, C2) are computed.
    • aout is initially guessed from the previous time step's value.
    • The continuity equation is solved for aout.

• Error Handling: Reports an error if the continuity equation isn't solved.

• Compute Normalized Outlet Flow: Based on aout.

• Save New Flows and Areas: Update conduit properties with new flow and area values.

• Return: The number of iterations used or an error code.

Function's Role in SWMM5 🏗️💧🖥️

• kinwave_execute is crucial for modeling how water moves through drainage networks, especially in urban flood scenarios.
• Helps in predicting the response of drainage systems to various rainfall events.

Implementation Details 🔍🔧

• Uses advanced mathematical concepts like continuity equations and Newton-Raphson root finding.
• Integral part of the SWMM5 engine, contributing to its robustness in simulating stormwater runoff and drainage systems.

In summary, kinwave_execute function is a core computational element in SWMM5, applying kinematic wave principles to predict flow dynamics in stormwater drainage systems, crucial for urban hydrology modeling and flood management. 🌊🖥️🧑‍💻📊🛠️🌧️🔍🌍🔄💧📈🚀🔬🌆