InfoSewer EPS Rules - Muskingum-Cunge technique

 InfoSewer 🖥️ tracks the movement of wastewater 💧 flowing through the network 🌐 over an extended period of time 📅 under varying wastewater loading and operating conditions 🔄. The extended period simulation (EPS) model 📊 implemented in InfoSewer is unsteady 🌊 and is based on the 1D Saint-Venant equations 📜.

The Saint-Venant equations 📝 or full dynamic wave equations for open channel flow routing consist of:

1. Conservation of momentum equation 🌀
2. Equation of continuity 🌊

Details of the equations and parameters (x, A, y, d, Q, V, S0, θ, Sf, g, t, β) are given 📄.

To solve these equations efficiently, especially for large sewer systems 🌐, simplified methods like non-inertial, kinematic wave, and dynamic wave are used 🔄. InfoSewer utilizes the Muskingum-Cunge technique 🌀 for unsteady open channel flow and the energy equation for pressurized flow in pipes.

Flooding 🌊 at manholes and wet wells is not modeled during an EPS in InfoSewer. Instead, flows are conserved 🔄. Actual flooding might divert flows away from structures, potentially causing issues with regulations and health codes 🚫.

SURCHARGE ⚠️: Sewer pipes can experience surcharge flow when the flow rate exceeds capacity. The conditions and consequences of surcharge, along with modeling approaches, are detailed 📄.

FLOW ATTENUATION 📉: As flow travels downstream, it can experience attenuation due to various factors. InfoSewer uses the Muskingum-Cunge method to accurately predict this attenuation 🌊.

HYDROGRAPH AGGREGATION/FLOW ACCUMULATION 📊: Multiple hydrographs with distinct time steps can merge in a sewer system. Aggregating these accurately is crucial. InfoSewer employs a dynamic method to ensure accurate aggregation, preserving both flow peaks and volumes 📈.