NUCL350 Exam 2 Review (Chapters 4 & 5)

Field representation

Describes how a physical quantity, such as velocity or pressure, varies over space and time.

Velocity field

A vector field that shows the velocity of a fluid at every point in space and time.

Eulerian method

Observes fluid flow at fixed points in space as the fluid moves through them.

Lagrangian method

Tracks individual fluid particles as they move through space and time.

One-dimensional flow

Describes fluid flow constrained to one spatial dimension.

Two-dimensional flow

Describes fluid flow constrained to two spatial dimensions.

Three-dimensional flow

Describes fluid flow constrained to three spatial dimensions.

Steady flow

Flow where fluid properties at any point do not change with time.

Unsteady flow

Flow where fluid properties vary with time at any point.

Streamline

A curve that is tangent to the velocity vectors of the flow at every point, showing the direction of the flow.

Streakline

A line that represents the locus of all fluid particles that have passed through a particular point in space.

Pathline

The actual path followed by an individual fluid particle over time.

Acceleration field

A vector field representing the acceleration of fluid particles at every point in space and time.

Material derivative

The rate of change of a fluid property (such as velocity) as observed from a moving fluid particle.

Local acceleration

The change in velocity at a fixed point in space over time.

Convective acceleration

The change in velocity of a fluid particle due to its movement through a velocity gradient in space.

System

A collection of fluid particles that is observed as it moves through space.

Control volume

A fixed region in space through which fluid may flow in and out, used for analyzing fluid systems.

Reynolds transport theorem

A fundamental equation that relates the rate of change of a property in a control volume to the flux of that property across its boundaries.

Conservation of mass

The principle that mass cannot be created or destroyed in a closed system.

Continuity equation

A mathematical expression of conservation of mass in fluid flow, stating that the mass flow rate is constant along a streamline.

Mass flow rate

The amount of mass passing through a given area per unit time.

Linear momentum equation

Describes how the momentum of a fluid changes due to forces acting on it.

Moment-of-momentum equation

Relates the angular momentum of a fluid to the torques acting on it.

Shaft power

The mechanical power transmitted through a rotating shaft, typically in turbines or engines.

Shaft torque

The twisting force exerted by a shaft, related to its rotational motion.

First law of thermodynamics

States that energy cannot be created or destroyed, only transferred or converted from one form to another.

Heat transfer rate

The amount of thermal energy transferred per unit time.

Energy equation

Describes the conservation of energy in a fluid system, accounting for internal, kinetic, and potential energies.

Loss

The dissipation of energy in a system, typically due to friction or inefficiencies.

Shaft work head

The energy per unit weight of fluid associated with shaft work in a mechanical system.

Head loss

The reduction in fluid's energy or head due to friction, turbulence, or obstructions in a flow system.

Kinetic energy coefficient

A factor that accounts for variations in velocity across a flow area when calculating kinetic energy.

Define the concept of the field representation of a flow.

the description of fluid properties (like velocity, pressure, or temperature) as continuous functions of space and time, every point in the flow field has a value for each property allowing for very detailed analysis

What is the difference between the Eulerian method and the Lagrangian method of describing flow?

the Eulerian method looks at flow from fixed positions, while the Lagrangian method tracks moving fluid particles

What is the difference between streamlines, streaklines, and pathlines?

steady flow: all three coincide and look the same

unsteady flow: streamlines show the direction a fluid element will move at a specific instant, streaklines identify fluid elements that have gone through a specific location, and pathlines are the paths that fluid elements follow through a flow

What is the difference between a system and a control volume?

A system follows specific fluid particles, while a control volume is fixed in space allowing fluid to pass in and out of its boundaries