Closure to “Air demand prediction and air duct design optimization method for spillway tunnel”

where Co is the so-called choking number (Crispino et al., 2019; Stahl & Hager, 1999), F the approach Froude number, Y∗ = Ht/h0 the sequent depth ratio for pressurized flows for a rectangular tunnel, Ht the tunnel height and h0 the water depth. When Eqs (1) and (2) are applied, the detailed parameters of the spillway tunnel of Jinping-I dam are listed in Table C1, in which s is the gate opening percentage, hgate the height of gate opening, hc the water depth of the contraction section downstream the gate (Henry, 1977), B the tunnel width, Hteq = A/B the equivalent tunnel height and A ≈ 206m2 the sectional area Figure C1 Comparison of β: (a) prototype observations, (b) Eq. (1), (c) the model of the original article