Chute spillways The flow coming into the spillway is subcritical. The slope of the chute causes the flow velocity to increase. Typically, supercritical flow is maintained in the chute.

What is chute spillway?

Chute spillway is an open channel like structure, which is constructed on steep slope of the gully face with a suitable inlet and outlet. It usually consists of an inlet, vertical curve section, steep-sloped channel and outlet. The major part of the drop in water surface takes place in a channel.

Where do we provide chute spillway?

Chute spillway is suitable for gravity dams, earthen dams, rockfill dams, etc. But it is preferred when the width of the river valley is very narrow. The water flows along the steeply sloped chute or trough or open channel and reaches the downstream of the river.

What is spillway capacity?

Spillway capacity is preserved as the low profile of the Obermeyer Gate System allows efficient passage of flood flows without any significant increase in flood pond elevation. This prevents dangerous overtopping of dam embankments or flood damage to upstream properties.

What conveys spillway discharge to the downstream side?

Chute (open channel or trough) spillway is a spillway whose discharge is conveyed from the upper reach of the channel or a reservoir to the downstream channel level through an open channel placed along a dam, abutment (supporting wall), or through a saddle.

Chute Spillway Design GATE AG 2018 Q-45

27 related questions found

What is the function of spillway?

The primary function of spillway is to release surplus waters from the reservoir in order to prevent overtopping and possible failure of the dam.

What are the components of a chute spillway?

There are four main components of a chute spillway: The elements of a spillway are the inlet, the vertical curve section (ogee curve), the steep-sloped channel and the outlet. In order to avoid a hydraulic jump, the slope of the spillway must be steep enough for the flow to remain supercritical.

Where is spillway located?

A spillway is located at the top of the reservoir pool. Dams may also have bottom outlets with valves or gates which may be operated to release flood flow, and a few dams lack overflow spillways and rely entirely on bottom outlets.

How do spillways work?

As soon as any excess water enters the reservoir, water will start flowing out through the spillway. It works similar to an overflow hole in a bathtub or sink at home, where if water levels go too high it'll go into the hole and through the drain.

What is the function of spillway in hydroelectric power plant?

A spillway is a structure constructed in a hydroelectric dam to provide a safe path for floodwaters to escape to some downstream area. Generally, the area that the spillway is released to is the river on which the hydroelectric dam was constructed.

Why are spillway provide in a dam?

“Spillways are structures constructed to provide safe release of flood waters from a dam to a downstream area”. Every reservoir has a certain capacity to store water. If the reservoir is full and flood water enters it, the reservoir level will go up and may eventually result in over-topping of the dam.

How does a siphon spillway work?

This spillway consists of one or a number of units of conduits formed by inverted U-tubes. When water level in the reservoir rises, the water first flows as for the weir spillway. ... when air inlet is block by rising water, siphonic action starts and spillway starts discharging with full capacity.

What is spillway or weir?

A weir is an impervious barrier constructed across a river to raise the water level on the upstream side. ... In a weir the water overflows the weir, but in a dam the water overflows through a special place called a spillway. Weirs have traditionally been used to create mill ponds.

What is drop inlet spillway?

A drop inlet or shaft spillway is one in which the water enters through a horizontally positioned circular or rectangular box type riser or inlet and flows to some type of outlet protection through a circular (horizontal or near horizontal) conduit. ... It consists of an earthen dam and a pipe spillway.

What are spillway types?

The types are: 1. Free Over-Fall (Straight Drop) Spillway 2. Ogee (Overflow) Spillway 3. Side Channel Spillway 4. Chute (Open Channel or Trough) Spillway 5.

What is an auxiliary spillway?

Auxiliary Spillway / Emergency Spillway - Any secondary spillway that is designed to be operated infrequently, possibly in anticipation of some degree of structural damage or erosion to the spillway that would occur during operation.

How were spillways formed?

The spillway is the most distinctive erosional landform formed by glacial-lake outbursts along the southern margin of the Laurentide Ice Sheet. ... Spillways can sometimes be divided into two major components: a narrow, deep inner channel and a scoured sub-upland surface (Figs.

How do spillways prevent flooding?

They regulate the reservoir level simply by existing. If it gets too high, water flows out and the pool goes down. If the pool is below the crest, no water is released, and the level goes up as precipitation makes its way into the reservoir.

What is spillway in irrigation engineering?

Definition of Spillway.

Spillway is a waterway provided to dispose of surplus flood water from a reservoir after it has been filled upto its maximum capacity. Spillways are provided for all the dams and these act as safety valves for the dam.

What is the meaning of spillway in fishing?

A channel for an overflow of water, as from a reservoir.

Is the over flow section or portion of the dam?

Explanation: A spillway is the overflow section or portion of the dam over which surplus discharge flows from reservoir to downstream face. This structure is provided in the body of the dam or near the dam or on the periphery of the reservoir. 15.

What is a drum gate?

: a hinged gate at the top of a dam consisting of a horizontal cylindrical sector that can be raised from its compartment to increase the height of the spillway.

Why cavitation occurs in ogee spillway?

Cavitation damage occurs on concrete surface when discontinuity or irregularities is encountered in the path of high velocity water flow. This discontinuity or irregularity in the flow path cause the water to lift off the flow surface, creating negative pressure zones and resulting bubbles of water vapor.

What is meant by a spillway?

spillway, passage for surplus water over or around a dam when the reservoir itself is full. Spillways are particularly important safety features for several types of dams.

What are the requirements of spillway?

Essential Requirements of Spillway:

The Spill way's bounding surface must be erosion resistant to withstand the high velocity flow created due to the drop in the water surface from the reservoir level upstream to the tail water level downstream to the dam.