FLUID MECHANICS COMPREHENSIVE EXAM SCRIPT VERIFIED QUESTIONS AND SOLUTIONS GRADED APLUS

FLUID MECHANICS COMPREHENSIVE
EXAM SCRIPT VERIFIED QUESTIONS AND
SOLUTIONS GRADED APLUS

●● Solid vs fluid under shear
Answer: A solid can deform and stop at a fixed strain. A fluid keeps
deforming/flowing under shear stress.


●● Liquid
Answer: Has relatively constant volume, takes container shape, and can
form a free surface in a gravitational field.


●● Gas
Answer: Expands to fill available space and does not form a free surface
in an open container.


●● Viscous flow
Answer: Flow where frictional/viscous effects are significant, especially
near solid surfaces and in boundary layers.


●● Inviscid flow region
Answer: A flow region where viscous forces are negligible compared
with inertial or pressure forces, often away from walls.

, ●● Internal flow
Answer: Flow completely bounded by solid surfaces, such as pipe or
duct flow.


●● External flow
Answer: Flow over an object or surface, such as airflow over a ball,
plate, or vehicle.


●● Incompressible flow
Answer: Flow where density remains nearly constant, commonly liquid
flows and low-speed gas flows.


●● Compressible flow
Answer: Flow where density changes significantly, common for high-
speed gas flow.


●● Mach number
Answer: Ratio of flow speed to speed of sound. Ma < 1 subsonic, Ma =
1 sonic, Ma > 1 supersonic, Ma >> 1 hypersonic.


●● Laminar flow
Answer: Highly ordered fluid motion characterized by smooth layers,
usually at low Reynolds number or high viscosity.