What are the classifications of flow profile?
Flow profiles are classified by the slope of the channel (So), yn, and yc. There are five slope classifications designated by the letters C, M , S, A, and H (critical, mild, steep, adverse, and horizontal) respectively.
How many surface profiles are possible in Gvf?
Table 1 shows the four (4) classes of water-surface profiles and the twelve (12) possible profiles.
Which one of the following is gradually varied flow?
nonuniform flow characterized by gradual variations in flow depth and velocity (small slopes and no abrupt changes) and a free surface that always remains smooth (no discontinuities or zigzags).
What is the equation of gradually varied flow?
The basic governing equation of the steady GVF in open channels is given by , (1) dy dx = S 0 – S f 1 – F 2 where y = depth of flow (m), x = distance along the channel, measured positive in the downstream direction (m), dy/dx = slope of the free surface at any location x, S0 = longitudinal slope of the channel …
How are the GVF profile classified?
10. A gradually varied flow profile is classified based on the channel slope, and the magnitude of flow depth, y in relation to yn and yc . The channel slope is classified based on the relative magnitudes of the normal depth, yn and the critical depth, yc .
Which GVF profile is negative dY dX?
From this, we can see that only M₂, S₂, H₂, and A₂ are the negative GVF profiles.
What are the assumptions of GVF?
Some of the important assumptions under which the gradually varied flow (GVF) holds ideal are: The slope of the channel/canal is very small. The vertical depth is considered from the bottom. The pressure distribution is hydrostatic because the curvature of streamlines is small.
Which method is used for computation of GVF?
The direct integration method is used to compute free surface profiles in gradually varied flow (GVF) along the length of a prismatic open channel.
What is backwater profile?
Profile of water surface elevation above a specified reference level along a flow path, usually upstream from an obstruction.
How does GVF calculate normal depth?
The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0. The water depth gets closer to Yn as the calculation proceeds further and further upstream. If Yc>Ys, then the slope is a C3. The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax.
What causes gradually varied flow?
Explanation: Gradually varied flow is steady non-uniform because the velocity of water remains constant at a specified point, but it changes from one point to another point.
What is the expression for head loss in case of a Gvf?
What is the expression for head loss in case of a GVF? Therefore, hf = LSf. 2.
When so is less than zero it is called?
Explanation: When So is less than zero, it is called Adverse slopes.
What is the difference between gradually varied flow and rapidly varied flow?
Rapidly varied flow (RVF) occurs over a short distance near the obstacle. Gradually varied flow (GVF) occurs over larger distances and usually connects UF and RVF.
What is gradually varied flow in open channel?
A steady non-uniform flow in a prismatic channel with gradual changes in its water- surface elevation is named as gradually-varied flow (GVF). The backwater produced by a dam or weir across a river and drawdown produced at a sudden drop in a channel are few typical examples of GVF.
What is called afflux in gradually varied flow?
Afflux: It is defined as a maximum increase in water level due to obstruction in the path of the flow of water. The profile of rising water on the upstream side of the dam is called a backwater curve. Hence, the backwater curve is the profile of the rising water on the upstream side of the obstruction.
What are the classifications of open channel flow?
Since the publication of the paper by Robertson and Rouse in 1941 (10), open channel flow has been classified into the following four regimes: laminar-subcritical, turbulent-subcritical, laminar-supercritical, and turbulent-supercritical.
What are differences between uniform and non-uniform flow?
In uniform flow if the velocity at a given instant of time is same in both magnitude and direction at all points in the flow, the flow is said to be uniform flow. When the velocity changes from point to point in a flow at any given instant of time, the flow is described as non-uniform flow.
Can rapidly varied flow be unsteady?
Both gradually varied and rapidly varied unsteady flows are possible, and the same general rules for analysis apply as for steady flow. The zones of rapidly varied flow must be isolated before analysis under the 1-D flow assumption; thus, the method of analysis for steady and unsteady flow is the same in this respect.
What are the 3 types of flow?
There are three fluid flow regimes: laminar, turbulent, and a transition region. The conditions that lead to each type of flow behavior are system-specific.
What are the 3 type of open channel flow meters?
The meter calculates the average channel velocity from sensed velocity actually measured by the meter in one of three ways; incoherent/continuous Doppler, coherent (profiling) Doppler, or electromagnetic.