ME Review Course: Fluid Mechanics and Power Cycles

Comprehensive vocabulary flashcards covering fluid properties, dynamics, machineries, and internal combustion cycles based on the PRIME Review Center Mechanical Engineering notes.

Ideal fluid

A fluid that is assumed to be frictionless and incompressible in flow problems.

Hydrostatic paradox

The statement that the hydrostatic pressure a fluid exerts on an immersed object or on container walls is a function only of fluid depth.

Hydraulics

The study of the practical laws of fluid flow and the resistance of open pipes and channels.

Newtonian fluid

A fluid where the shear stress is directly proportional to the rate of strain.

Vena contracta

The location in a fluid jet where the diameter is minimum, typically at a distance approximately $1/2$ the diameter of the orifice.

Viscosity Index

A measure of a fluid's sensitivity to changes in viscosity with changes in temperature.

Compressibility

Refers to the fractional change in fluid volume per unit change in fluid pressure.

D'Alembert's paradox

The known fact that there is no resistance to bodies moving through an ideal (non-viscous) fluid.

Tranquil flow

Flow of a fluid that must always occur above the critical depth.

Bernoulli's equation

A conservation of energy equation valid along a streamline for incompressible and inviscid fluids.

Kinematic viscosity

Dynamic viscosity divided by fluid density, often expressed in units like $ft^{2}/sec$ or centistokes.

Hydraulic radius

The ratio of the cross-sectional area of flow to the wetted perimeter.

Cavitation

The result of static pressure in a fluid becoming less than the fluid vapor pressure, causing the formation and collapse of vapor bubbles.

Water hammer

A dynamic, time-dependent fluid mechanics phenomenon involving compressible fluid effects.

Stream function

A useful parameter in fluid mechanics used to describe the conservation of mass.

Terminal velocity

The speed achieved by a falling object when the drag force equals its weight.

Mach number

The ratio of the actual velocity of the fluid to the velocity of sound; supersonic flow occurs when this is greater than $1$.

Weber number

A dimensionless parameter used in fluid dynamics studies involving surface tension.

Pascal's Law

The principle stating that at any point in a fluid at rest, the pressure is the same in all directions.

Hydrometer

An instrument used to determine the relative density or specific gravity of liquids.

Stalling

The reduction in lift force at a higher angle of incidence in an axial flow compressor.

Bore

The diameter of the circular cylinder in an internal combustion engine.

Stroke

The maximum distance traveled by a piston within a cylinder.

Supercharging

The process of supplying intake air to an engine cylinder at a density higher than the surrounding atmosphere.

Detonation

The process in which violent sound pulsations are produced within the cylinder of an internal combustion engine.

Regenerator

A heat exchanger used to provide heat transfer between exhaust gases and air prior to its entrance to the combustor.

Top dead center (TDC)

The position of the piston when it is at its maximum reach from the crankshaft.

Otto cycle

A thermodynamic cycle consisting of two isentropic processes and two constant volume processes.

Diesel cycle

A thermodynamic cycle consisting of two isentropic processes, one constant pressure heat addition, and one constant volume heat rejection.

Dual cycle

A thermodynamic cycle where combustion occurs partly at constant volume and partly at constant pressure.

Compression ratio ($r_{k}$)

The ratio of the volume at the beginning of compression to the volume at the end of compression.

Cut-off ratio ($r_{c}$)

The ratio of the cylinder volume after constant pressure heat addition to the volume before it in a Diesel cycle.