Quick Answer: How Is Channel Area Calculated?

What is the formula of discharge?

Discharge (also called flow rate) If v is the mean velocity and A is the cross sectional area, the discharge Q is defined by Q = Av which is known as volume flow rate.

Discharge is also expressed as mass flow rate and weight flow rate..

How do you calculate depth?

If you have several objects that have a depth, then you can calculate the average depth. The average depth looks at how deep all the objects are when considered together. The formula for average is the sum of all the depths divided by the number of depths you have. Measure all of your depths.

What is bed slope?

The depth–slope product is used to calculate the shear stress at the bed of an open channel containing fluid that is undergoing steady, uniform flow. … It is the product of the water depth and the mean bed slope, along with the acceleration due to gravity and density of the fluid.

How do you find the slope of a river?

Calculate the channel slope. Using the formula, slope equals change in elevation divided by ground distance. For example, if the ground distance is 11/16 or 0.69 inches and the scale factor is 1 inch equals 2,000 feet per inch, this equals 1,380 feet. The channel slope is 10 divided by 1,380, which equals 0.0072.

How do you calculate the hydraulic radius of a pipe?

Rh is the hydraulic radius = A/P. P is the wetted perimeter of the cross-sectional area of flow in ft. *You may recall that uniform open channel flow (which is required for use of the Manning equation) occurs for a constant flow rate of water through a channel with constant slope, size and shape, and roughness.

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.

How do you find the rise and run of slope?

To do this, multiply the slope by the run. Solve the equation. For example, if the slope of the line is -1 and its run is -3, multiply -1 by -3. The result is the rise.

How do you find the hydraulic radius of a channel?

In order to calculate hydraulics radius first of all cross section area of the rectangular channel must be calculated then wetted perimeter of the channel is calculated. Once we have area and wetted perimeter then simply divide the area over wetted perimeter.

What value is calculated by multiplying the area of a channel by the average velocity of the water?

By multiplying the cross-sectional area (width of section x stage height) by the velocity, one can calculate the discharge for that section of stream. The discharge from each section can be added to determine the total discharge of water from the stream.

What is 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 are the sides of a channel called?

Characteristics of Streams The channel is always there even if no water is running in it. The deepest part of the channel, the route taken by the last (or first) bit of water, is called the thalweg (TALL-vegg, from the German for “valley way”). The sides of the channel, along the edges of the stream, are its banks.

What is critical depth?

Critical depth is defined as the depth of flow where energy is at a minimum for a particular discharge.

What is the wetted perimeter of a channel?

In open channel flow, the wetted perimeter is defined as the surface of the channel bottom and sides in direct contact with the aqueous body. Friction losses typically increase with an increasing wetted perimeter, resulting in a decrease in head.

What is side slope?

Side slope (Figure 5-2) is defined as the slope of the cut or fill expressed as the ratio of horizontal distance to vertical distance.

How do you calculate channel flow rate?

Using the equation, V = Q/A as a definition for average flow velocity, the Manning Equation becomes: V = (1.49/n)(R2/3)(S1/2), with average flow velocity in ft/sec. In S.I. units this equation becomes: V = (1.0/n)(R2/3)(S1/2), with average velocity in m/s.

How is open channel discharge calculated?

The DCM is based on the uniform velocity in the area. In this method, the compound channel section is divided into the main channel and the floodplains, and then the total discharge is calculated by adding the discharge through the area.

What is channel slope?

Channel slope or gradient is the difference in elevation between two points on a stream divided by the distance between them measured along the stream channel.

Is it possible to use Venturi meter for measuring discharge in an open channel?

Flow rate measurement in open channel : VENTURI CHANNEL. Manufactured Venturi channels are dedicated for flow rate measurement in open flumes, and totalization on effluents. They are useful either on waste water, contaminated fluid even with solids/ particles or chemically aggressi- ve.

What is channel shape?

The cross-sectional shape of a natural stream channel is determined by streamflow, the amount and type of sediment carried by the stream and the rocks, soils and vegetation that make up the bed and banks of the channel. Most natural channels tend to be asymmetrical at bends and trapezoidal in straight stretches.