Haha.. nice to see you on here again Doone. Florida was fun, but I am glad to be back. As for Nashville, you should check it out again... MANY changes here the past 10 years, including the arrival of the Titans & Predators!
Purpose: The purpose of this note is to explain a significant dynamic wave routing difference between EPA SWMM 5.0.013 and EPA SWMM 5.0.011 and before. A few people have detected a difference. The previous solution(s) would use only the midpoint area (Amid) and hydraulic radius (Rmid) in the dynamic wave solution. The new solution will use a slider or linear combination of the midpoint area (Amid) and hydraulic radius (Rmid) and the upstream cross sectional area (A1) and hydraulic radius (R1). The slider is based on the Froude number in the link. The change involves the A and R link spacing in the two dominant terms of the St. Venant Equation:
The new method is a linear combination or slider that weights the value of A and R in the St. Venant Equation based on the value of rho (), or
), or
