hydReng (version 0.1.0)

pressflow_depth_sub: Backwater Height Upstream A Inlet Under Pressure (Bernoulli)

Description

Calculates the backwater height upstream of an inlet (pipe or rectangle) under pressure (Bernoulli). The outlet is submerged; hence, an exit loss (xi_a) has to be specified.

Usage

pressflow_depth_sub(
  z0, z1, Q, h1, v1, Di = NULL, h = NULL, b = NULL, L, ks = NULL, kst, xi_a,
  xi_e = 0.5, nu = 1.14e-6, calc_lam = "kst"
)

Value

Returns the backwater height upstream the inlet:

h0

Water depth upstream the inlet [m].

v

Flow velocity [m/s].

Arguments

z0

Absolute height of upper gate – upstream of the inlet [m.a.s.l].

z1

Absolute height of the pipe/rectangle vertical middle axis at lower gate [m.a.s.l].

Q

Flow [m^3/s].

h1

Water depth downstream the outlet [m].

v1

Velocity downstream the outlet [m/s].

Di

Diameter of pipe [m]. If Di is specified, h and b must be NULL.

h

Height of rectangle [m]. If h is specified, Di must be NULL.

b

Width of rectangle [m]. If b is specified, Di must be NULL.

L

Length of pipe [m].

ks

Equivalent sand roughness [m].

kst

Roughness [m^(1/3)/s].

xi_a

Exit loss, according to Borda-Carnot formula (1 - A1/A2)^2 [-].

xi_e

Entrance loss [-]. Default = 0.5.

nu

Kinematic viscosity [m^2/s]. Default = 1.14e-6.

calc_lam

Defines if lambda should be calculated with ks or kst.

Examples

# Flow in a pipe under pressure with ks value
pressflow_depth_sub(z0=415,z1=413,Q=5.18,h1=2,v1=4,L=20,Di=1,ks=0.01,
calc_lam="ks",xi_a=0.5)

# Flow in a rectangle under pressure with kst value
pressflow_depth_sub(z0=415,z1=413,Q=13.7,h1=2,v1=4,L=20,b=2,h=1,kst=60,
calc_lam="kst",xi_a=0.5)