What is the critical depth?
Critical depth is defined as the depth of flow where energy is at a minimum for a particular discharge. Flow profiles are classified by the slope of the channel (So), yn, and yc.
What is bed slope in open channel?
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.
What is relation between C and N in open channel flow?
C. Vegetated or grassed channels (ditches or waterways) are the most complicated to design because the roughness of the channel, i.e., vegetation height, may be comparable to the depth of flow. This results in the Manning’s n being a function of flow velocity and hydraulic radius rather than a constant.
What is normal depth in open channel flow?
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 critical depth in open channel?
Critical Flow: The variation of specific energy with depth at a constant discharge shows a minimum in the specific energy at a depth called critical depth at which the Froude number has a value of one. Critical depth is also the depth of maximum discharge, when the specific energy is held constant.
What is alternate depth?
Alternate depths are defined as the depths of flow in open channels for which the specific energy is the same. Solution to problems concerning transition in the width and bottom of the channels requires computation of alternate depths.
What is bottom slope?
Definition: Break line representing the lower boundary of an area having a constant slope in the terrain surface, typically varying approximately between 2° and 40°.
What is an adverse slope?
When an unsteady free surface flow encounters an adverse slope, it results in a decelerating flow up the adverse slope.
What is water surface slope?
The water surface profile within a culvert can be classified two different ways: 1. Hydraulic Slope, which is based on the slope of the culvert bottom and. 2. Hydraulic Curve, which is based on the relationship of the water depth relative to critical depth and normal depth.
How many surface profiles are possible on a steep channel?
Thus, we have 13 different types of surface profiles: three for the mild slope, three for the steep slope, two for the critical slope (zone 2 does not Page 6 124 5 GRADUALLY VARIED FLOW exist since yn = yc and we do not consider the critical-depth line as a surface profile); two for the horizontal slope (zone 1 does …
What is a water surface profile?
The water Surface Profile reports the results of the hydraulic calculations graphed in the culvert. Normal depth is the depth of flow in a channel or culvert when the slope of the water surface and channel bottom are the same and the water depth remains constant. …
When Froude number is between 2.5 to 4.5 The jump is said to be?
Explanation: An oscillating jump is a jump that takes place when the Froude’s number is in between 2.5 to 4.5. During this jump, the jet water at the entrance of the jump fluctuates. It fluctuates from the bottom of the channel to the top of the channel.
Why do hydraulic jumps occur?
A hydraulic jump occurs when the upstream flow is supercritical (F>1). To have a jump, there must be a flow impediment downstream. The downstream impediment could be a weir, a bridge abutment, a dam, or simply channel friction. Water depth increases during a hydraulic jump and energy is dissipated as turbulence.
When Froude number is between 1 to 1.7 What is the jump?
9. Classification of Hydraulic jump 1. Based on Froude number Classification of hydraulic jumps: (a) Fr =1.0 to 1.7: undular jumps; (b) Fr =1.7 to 2.5: weakjump; (c) Fr =2.5 to 4.5: oscillating jump; (d) Fr =4.5 to 9.0: steadyjump; 10.
How do you calculate conjugate depth?
Conjugate depths are determined by the one-dimensional momentum equation as follows:(14) Q 2 g A 1 + A 1 h c 1 = Q 2 g A 2 + A 2 h c 2 where A1 and A2 are the cross-sectional areas upstream and downstream of a hydraulic jump, respectively (m2), and hc1 and hc2 are the water depths from the centroids of the cross- …
What is upstream depth?
Definition of conjugate depths The depth upstream of a hydraulic jump is always supercritical, and the depth downstream of a hydraulic jump is always subcritical. It is important to note that the conjugate depth is different than the alternate depths for flow which are used in energy conservation calculations.
What is the use of blench curve?
Blench had given curves, relating HLandE1for di~ferent values of q (Plate IO. I). These curves are very useful in determining the location of the jump on a ;,;loping glacis, – as explained below. .
What is blench curve?
49. For a given discharge in a channel, Blench curves give the relationship between the loss of head (HL) and. [A]. specific energy up-stream. [B].
What is Montague’s curve?
Montague (minor planet designation: 535 Montague) is a minor planet orbiting the Sun that was discovered by Raymond Smith Dugan on 7 May 1904 in Heidelberg, Germany. It was named after the town Montague in Massachusetts. Photometric observations of this asteroid give a light curve with a period of 10.248 hours.
What is sloping Glacis?
A glacis (/ˈɡleɪ. sɪs/; French: [ɡlasi]) in military engineering is an artificial slope as part of a medieval castle or in early modern fortresses. A glacis plate is the sloped front-most section of the hull of a tank or other armoured fighting vehicle.