Hydraulics & Fluid Mechanics Flashcards
6 cards from real BCE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Hydraulics & Fluid Mechanics flashcards as text
What is the primary purpose of a surge tank in a hydroelectric or water supply system?
Answer: To reduce water hammer pressure fluctuations
A surge tank is a standpipe connected to a penstock that absorbs sudden pressure changes (water hammer) caused by rapid valve closure or load changes.
In hydrology, the unit hydrograph concept assumes that runoff from a watershed is:
Answer: Linear and time-invariant
The unit hydrograph theory assumes a linear, time-invariant relationship between effective rainfall and direct runoff for a given watershed.
Stokes' law describes the settling velocity of a particle in a fluid as proportional to which property of the particle?
Answer: The square of the particle diameter
Stokes' law states that the settling velocity vs = (γs - γ)d²/18μ is proportional to the square of the particle diameter d.
What does the hydraulic grade line (HGL) represent in a pressurized pipe system?
Answer: Pressure head plus elevation head
The HGL represents the sum of pressure head and elevation head (piezometric head) at each point along the pipe, showing where water would rise in piezometers.
Which equation governs the distribution of velocity in a turbulent boundary layer using the law of the wall?
Answer: Logarithmic velocity profile
The law of the wall uses a logarithmic velocity profile (u/u* = (1/κ)ln(y/y₀)) to describe turbulent flow near a boundary.
The coefficient of discharge Cd for a sharp-crested rectangular weir is typically approximately:
Answer: 0.62
The coefficient of discharge for a sharp-crested rectangular weir is approximately 0.62, accounting for contraction and velocity effects.