In a reaction turbine, the draft tube is used
A. To run the turbine full
B. To prevent air to enter the turbine
C. To increase the head of water by an amount equal to the height of the runner outlet above the tail race
D. To transport water to downstream
Answer: Option C
Solution (By Examveda Team)
In a reaction turbine, the draft tube is used:To increase the head of water by an amount equal to the height of the runner outlet above the tail race: The draft tube helps in converting the velocity head of the water exiting the turbine into pressure head, thus increasing the effective head and improving the efficiency of the turbine.
This function of the draft tube ensures that the water exiting the turbine maintains a higher pressure, which enhances the turbine's performance.
The draft tube does not run the turbine full, prevent air from entering, or transport water downstream.
This Question Belongs to Mechanical Engineering >> Hydraulics And Fluid Mechanics In ME
Cavitation damage in turbine runner occurs near the