The main function of an energy dissipator in a hydraulic structure is to
- AConvert kinetic energy into heat
- BStore excess water
- CPrevent erosion and cavitationCorrect
- DIncrease the velocity of water
Solution
Concept
Purpose of energy dissipators
Step-by-step solution
1. Water leaving a spillway has a very high velocity and kinetic energy. 2. Energy dissipators destroy this energy by creating turbulence, so that the downstream channel does not erode. 3. The aim is to prevent scour, erosion and cavitation damage.
Explanation
Structures such as stilling basins, bucket-type dissipators and baffles are provided at the toe of spillways to dissipate the energy of high-velocity flow and prevent erosion and cavitation of the downstream channel and structure.
Shortcut
Dissipator: kill the energy → protect the channel.
Common mistake
Choosing the mechanism (A) when the purpose is asked.
Correct answer: C) Prevent erosion and cavitation