Fluid Mechanics Flashcards
7 cards from real BME practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Fluid Mechanics flashcards as text
Reynolds Transport Theorem relates the time rate of change of an extensive property in a:
Answer: Control volume to a system (material volume)
Reynolds Transport Theorem converts conservation laws from a Lagrangian system (fixed mass) to an Eulerian control volume formulation.
In pipe network analysis using the Hardy-Cross method, iterations are performed to satisfy:
Answer: Mass continuity at each node and energy balance around each loop
Hardy-Cross iterates flow corrections until both nodal flow continuity and loop head-loss balance (∑h_f = 0) are satisfied simultaneously.
The 'no-slip condition' in viscous fluid mechanics states that:
Answer: The fluid velocity at a solid wall equals the wall velocity
The no-slip condition requires that viscous fluid immediately adjacent to a solid surface moves at the same velocity as the surface.
Which statement correctly describes the difference between Newtonian and non-Newtonian fluids?
Answer: Newtonian fluids have constant viscosity; non-Newtonian fluids have viscosity that depends on shear rate
Newtonian fluids have a linear stress–strain rate relationship (constant μ); non-Newtonian fluids (e.g., blood, paint) exhibit shear-dependent viscosity.
The Buckingham π theorem states that if a physical problem involves n variables and k fundamental dimensions, the number of independent dimensionless groups is:
Answer: n − k
Buckingham π theorem: the number of independent dimensionless Π groups equals n (variables) minus k (fundamental dimensions).
In the k-ε turbulence model, the variable ε represents:
Answer: Rate of dissipation of turbulent kinetic energy
In the k-ε model, k is turbulent kinetic energy and ε is the rate at which k is dissipated into heat by viscous action.
A manometer uses a U-tube filled with a denser fluid to measure pressure differences. If the manometer fluid is mercury (SG = 13.6) and the height difference is 15 cm, the pressure difference is approximately:
Answer: 20.0 kPa
ΔP = ρgh = 13.6×1000×9.81×0.15 ≈ 20,012 Pa ≈ 20.0 kPa.