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 does Froude number tell you?
Froude number (Fr), in hydrology and fluid mechanics, dimensionless quantity used to indicate the influence of gravity on fluid motion .
What is a high Froude number?
When Fr is less than 1, small surface waves can move upstream; when Fr is greater than 1, they will be carried downstream ; and when Fr = 1 (said to be the critical Froude number), the velocity of flow is just equal to the velocity of surface waves. ...
When Froude number is more than 1?
If the Froude number is less than 1, flow is said to be subcritical or slow; if Fr = 1, flow is critical; and if Fr is greater than 1, flow is fast or supercritical .
What is the difference between Reynolds number and Froude number?
Reynolds number deals with the relationship between frictional and inertial forces while Froude number deals with the relationship between gravity and inertial forces. It may then be necessary to compensate for the effect of the other force.
What is the limit of Froude number?
Water measurement in open channel flow
How do you find 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 will be the flow if Froude No is less than 1?
If the Froude number is less than 1, flow is said to be subcritical or slow ; if Fr = 1, flow is critical; and if Fr is greater than 1, flow is fast or supercritical.
When the Mach number is more than 6 the flow is called?
(d) When the Mach number is more than 6, the flow is called hypersonic flow .
What is critical depth?
Critical depth is also the depth of maximum discharge, when the specific energy is held constant . ... Normal Depth: For a given channel geometry, slope, and roughness, and a specified value of discharge Q, a unique value of depth occurs in a steady uniform flow.
What is the application of Reynolds number?
The Reynolds number, referred to as Re, is used to determine whether the fluid flow is laminar or turbulent . It is one of the main controlling parameters in all viscous flows where a numerical model is selected according to pre-calculated Reynolds number.
Can Reynolds number have decimals?
flow velocity (rounded to one decimal place), Froude number (rounded to two decimal places), • Reynolds number ( with no decimal places ). Then classify the flow conditions as laminar/turbulent and as supercritical/subcritical based on your calculations.
How do you use Reynolds number to scale?
The Reynolds number is used to study fluids as they flow . The Reynolds number determines whether a fluid flow is laminar or turbulent. Flowing fluids normally follow along streamlines. If a flow is laminar, fluids will move along smooth streamlines.
What is it called when Froude number lies between 1.7 to 2.5 then?
Weak Jump : Froude number for this flow is between 1.7 to 2.5.
What is Densimetric Froude number?
The densimetric Froude Number is defined as: Fm=uf/sqrt[g*h*(d_rho/rho)] , that is the depth averaged flow velocity over the density abnormally induced internal wave velocity.
What is Froude model law?
The law in which models are based on Froude Number is called as Froude’s model law. Whenever gravity forces are predominant over other forces for dynamic similarity, the Froude number for the model must be equal o Froude number for prototype .
