flow_max_freeboard: Maximum Flow Including Freeboard

In hydReng: Hydraulic Engineering Tools

Maximum Flow Including Freeboard

Description

Calculates the maximum discharge of a CSarbitrary object including a freebord for a given bottom slope under uniform flow conditions.

Usage

flow_max_freeboard(object, J, type = "KOHS", sigma_wz = 0, fw = TRUE, fv = FALSE, ft = 0,
fe = NULL, fe_min = 0, fe_max = Inf, method = "Strickler",
ret = "all", plot = FALSE)

Arguments

object	A CSarbitrary object.
J	Bottom slope [-].
type	Type of freeboard calculation. Defaults to "KOHS".
sigma_wz	Uncertainty in bed elevation (morphodynamics) [m].
fw	Logical; considers freeboard due to uncertainty in water elevation. If TRUE, calculates according to KOHS; if FALSE, sets fw = 0.
fv	Logical; considers freeboard due to waves. If 'TRUE', calculates according to KOHS; if FALSE, sets fv = 0.
ft	Freeboard due to driftwood based on KOHS (2013) [m].
fe	Fixed freeboard value to override calculations [m].
fe_min	Minimum freeboard [m].
fe_max	Maximum freeboard [m].
method	Method to calculate the roughness. Allowed are "Strickler" (equal roughness) and "Einstein" (mean roughness).
ret	Definition of the result returned by the function ("all", "Qmax", "hmax", "fe", or "v").
plot	Logical; whether to plot the results.

Value

Depending on ret, returns flow, water level, velocity, or all details.

References

KOHS (2013). Freibord bei Hochwasserschutzprojekten und Gefahrenbeurteilungen - Empfehlungen der Kommission Hochwasserschutz KOHS. Wasser Energie Luft 105(1): 43-53.

Examples

# Cross section
x <- c(-0.85, 3, 15, 18.85)
z <- c(3.85, 0, 0, 3.85)
cs<- CSarbitrary(x = x, z = z, xb_l = 3, xb_r = 15,
                                      kSt_B = 45)

# Channel
flow_max_freeboard(cs, sigma_wz = 0.3, fv = FALSE, J = 2.2 * 10^-2)
# Dam
flow_max_freeboard(cs, sigma_wz = 0.3, fv = TRUE, J = 2.2 * 10^-2)
# Bridge
flow_max_freeboard(cs, sigma_wz = 0.3, fv = TRUE, ft = 0.5,
           J = 2.2 * 10^-2)

# Sensitivity analysis for slope
J <- seq(1, 3, 0.1) * 10^-2
Q <- sapply(J, function(J) {
  flow_max_freeboard(cs, sigma_wz = 0.3, fv = TRUE, ft = 0.5,
             J = J)$Qmax
})
plot(J, Q, type = "l")

hydReng documentation built on April 4, 2025, 1:57 a.m.