What is the formula for Froude number?

It is generally expressed as Fr = v/(gd)1/2, in which d is depth of flow, g is the gravitational acceleration (equal to the specific weight of the water divided by its density, in fluid mechanics), v is the celerity of a small surface (or gravity) wave, and Fr is the Froude number.

What is Froude number in open channel?

In open channel hydraulics, the Froude number is a very important non-dimensional parameter. The Froude Number is a dimensionless parameter measuring the ratio of “the inertia force on a element of fluid to the weight of the fluid element” – the inertial force divided by gravitational force.

What is the formula for the area of a trapezoidal channel?

The hydraulic radius for flow in a trapezoidal open channel can be expressed in terms of y, b, and z, as follows: i) The cross-sectional area of flow, A, is the area of the trapezoid in Figure 4: A = y(b + B)/2 = (y/2)(b + B)

What is the formula of critical depth?

The governing equation for critical depth computation is [1](1) Q 2 g = A 3 B , where is the discharge given to compute the corresponding critical depth, is the gravitational acceleration, is the cross section area, and is the top width at the water surface.

What is Froude number in mixing?

The Froude number is the ratio of inertial forces to gravitational forces. In mixing, it can be used to describe vortex depth or wave height on the liquid surface.

When Froude number is 1 the type of jump is called?

Types of Hydraulic Jumps – Based on Froude’s Number: 1. Undular Hydraulic Jump – Froude Number (1 to 3): 2.

What is the Froude number in a channel at critical depth?

The critical depth for a rectangular channel can be calculated from the fact that the Froude number is equal to one at critical flow conditions. For a rectangular channel , this fact leads to the equation: Vc/(gyc)1/2 = 1, where the subscript c is used to indicate critical flow conditions for the velocity and depth.

What is trapezoidal channel?

Trapezoidal Channel is an open channel with a trapezoidal cross section where both sides have the same slope. The flow routing through a Channel Connection is described in Analysis of Connections. Parameters to specify: Length, Slope, Manning’s n, Diameter/Base Width, Height, Side Slope, see Connection Inputs.

Why does the trapezoid area formula work?

The area of this parallelogram is its height (half-height of the trapezoid) times its base (sum of the bases of the trapezoid), so its area is half-height × (base1 + base2). Because the parallelogram is made from exactly the same “stuff” as the trapezoid, that’s the area of the trapezoid, too.

How do you find the critical depth of a trapezoidal channel?

For a channel with a trapezoidal cross section, the critical flow condition is given by Fr = Vc/[g(A/B)c]1/2 = 1, where Ac = yc(b + zyc) and Bc = b + zyc2 , where z is the trapezoidal channel side slope (H:V = z:1).

What is the meaning of Froude number?

From Wikipedia, the free encyclopedia. In continuum mechanics, the Froude number (Fr) is a dimensionless number defined as the ratio of the flow inertia to the external field (the latter in many applications simply due to gravity).

How do you calculate the Froude number?

The Froude Number is a dimensionless parameter measuring the ratio of “the inertia force on a element of fluid to the weight of the fluid element” – the inertial force divided by gravitational force. The Froude Number can be expressed as. Fr = v / (g h m) 1/2 (1) where. Fr = Froude number.

How do you calculate the critical flow condition for a trapezoidal channel?

Calculations for a Trapezoidal Channel. For a channel with a trapezoidal cross section, the critical flow condition is given by Fr = Vc/[g(A/B)c]1/2 = 1, where Ac = yc(b + zyc) and Bc = b + zyc2 , where z is the trapezoidal channel side slope (H:V = z:1).

What is the Froude number in open channel flow?

Water measurement in open channel flow generally requires the Froude number to be less than 0.5 to prevent waves disturbing accurate head readings. When the Froude number is 1 the velocity is equal to the velocity of wave propagation and downstream waves or pressure disturbances cannot travel upstream.

What is the value of Froude number for hydraulic jump?

For a hydraulic jump to occur, the pre jump Froude number F r1 should be greater than 1. The post jump Froude number F r2 will be less than 1. The table below shows the values of the post jump Froude number F r2 for various values of pre jump Froude number F r1.