Discussion of “Jacobian Matrix for Solving Water Distribution System Equations with the Darcy-Weisbach Head-Loss Model” by Angus Simpson and Sylvan Elhay

Dejan Brkić (1)

1 European Commission

The general recommendation by Simpson and Elhay (2011) that the Hazen-Williams formula be replaced by the Darcy-Weisbach is heartily applauded. Today, this fact cannot be disputed. The main purpose of this discussion is to recommend more appropriate formulas for the calculation of the Darcy friction factor, λ which are more suitable for computation of the derivatives in a Jacobian matrix, and also to clarify a few points in the calculation of the flowdependent Jacobian.

Domaines: Sciences de l'ingénieur [physics]

Dejan Brkić. Discussion of “Jacobian Matrix for Solving Water Distribution System Equations with the Darcy-Weisbach Head-Loss Model” by Angus Simpson and Sylvan Elhay. Journal of Hydraulic Engineering, 2012, 138 (11), pp.1000-1001. ⟨10.1061/(asce)hy.1943-7900.0000529⟩. ⟨hal-01586518⟩