The energy grade line for steady flow in a uniform diameter pipe is shown. Which
ID: 1829004 • Letter: T
Question
The energy grade line for steady flow in a uniform diameter pipe is shown. Which of the following could be in the "black box"? (a) a pump, (b) a partially closed valve, (c) an abrupt expansion, or (d) a turbine. Choose all valid answer(s) and state your rationale.
The energy grade line for steady flow in a uniform diameter pipe is shown. Which of the following could be in the "black box"? (a) a pump, (b) a partially closed valve, (c) an abrupt expansion, or (d) a turbine. Choose all valid answer(s) and state your rationale.Explanation / Answer
the flow is steady and the pipe is of uniform diameter. hence the velocity will not change in the normal flow, although velocity may change in the black box region. hence we can say that the flow is taking place from right hand side to left hand side as we know that flow is only possible from high total head to low total head. due to frictional losses the EGL is decreasing linearly upto the black box and after the black box also. at the black box there is a significant loss of energy or head, it suggests that the black box may be anything which reduces the total energy suddenly. hence we can say from the options that the black box may be any of the three a) a partially closed valve b) an abrupt expansion c) a turbine it cannot be a pump as a pump is used in the opposite sense i.e, to increase the engergy or head. a partially closed valve decreases the energy of flow as the fuid is suddenly put to rest and the kinetic energy of fluid converts into strain energy stored in pipes. although an abrupt expansion is a very minor loss as compared to frictional losses but if the expansion is very abrupt, huge losses can take place. a turbine uses the kinetic energy or head of the fluid to convert it into mechaniocal energy hence the losses in energy takes place in the flow.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.