What is the critical depth denoted as?
The critical depth has a Froude number equal to one and corresponds to the minimum energy a flow can possess for a given discharge.
How is the critical depth affected by Q?
How critical depth is affected by the Q? As shown in the results, when the flow rate (Q) is lower, the critical depth is shallower. When the flow rate (Q) is higher, the critical depth is deeper.
What is the normal depth?
Normal depth is the depth of flow in a channel or culvert when the slope of the water surface and channel bottom is the same and the water depth remains constant. Normal depth occurs when gravitational force of the water is equal to the friction drag along the culvert and there is no acceleration of flow.
What is the condition for critical flow formula?
It is characterized, in addition, by a number of conditions [2, 12-14]: the water flow rate is maximum at a given specific energy; the velocity head is equal to half the average depth of the flow in the channel of a small slope; the Froude number is 1; the velocity of the flow in the channel of small slope with uniform
How is alternate depth calculated?
The depths of flow can be either PR = y1 or PR` = y`1. These two possible depths having the same specific energy are known as alternate depths. In Fig. (5.1), a line (OS) drawn such that E = y (i.e. at 450 to the abscissa) is the asymptote of the upper limb of the specific energy curve.
What is Hydraulic depth?
For use in Froude number and energy relationships in open channel flow hydraulics, mean depth, hm, is defined as the depth which, when multiplied by the top water surface width, T, is equal to the irregular section area, A, shown on figures 2-4a and 2-4b, of the flow section and is commonly used for critical flow
Why is critical depth important?
Critical depth is a quantity of fundamental importance to understanding the flow characteristics. If the actual depth is greater than critical depth, then the flow is considered “subcritical”. Subcritical flow is “slow flow” and is impacted by downstream conditions.
What is alternate depth?
Defining Terms Alternate depths — The subcritical or tranquil depth, y , and the supercritical or rapid depth y for a given specific energy and flowrate. Conjugate depths — The depths before and after a hydraulic jump corresponding to a given total thrust (or specific force) and flowrate.
How is Froude number calculated?
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 friction slope?
The rate at which energy is lost along a given length of channel is called the friction slope, and is usually presented as a unitless value or in units of length per length (ft/ft, m/m, etc.). Energy is generally added to a system with a device such as a pump.
How do you measure the depth of a river?
Place a metre ruler into the river until it touches the river bed. Record the distance between the river bed and the surface of the water. You should do this at regular intervals between the banks of the river. Add the depths together and divide by the number of recordings you took to calculate the mean depth.
What is the mean of depth?
noun. a dimension taken through an object or body of material, usually downward from an upper surface, horizontally inward from an outer surface, or from top to bottom of something regarded as one of several layers. the quality of being deep; deepness. complexity or obscurity, as of a subject: a question of great depth
What is meant by critical flow?
critical flow Critical flow occurs when the flow velocity in a channel equals the wave velocity generated by a disturbance or obstruction. In this condition the Froude number (Fr) = 1. When Fr is greater than 1 waves cannot be generated upstream and the flow is said to be supercritical, rapid, or shooting.
What is critical flow rate?
In the context of corrosion or errosion, critical flow rate is the maximum flow rate that avoids damage to the pipe from corrosion or erosion. In the context of liquid unloading, critical flow rate is the minimum flow rate to produce liquids from a well.