Chapter 5 - Bernoulli and Energy Equations

Conservation of Mass

Mass is a conserved property that cannot be created or destroyed during a process.

Closed Systems

A system where the mass remains constant during a process.

Control Volume

A designated volume within which mass can cross the boundaries, requiring tracking of mass entering and leaving.

Volume Flow Rate (℧̇)

The volume of fluid flowing through a cross section per unit time, often expressed as ℧̇ = V_avg * A_c.

Mass Flow Rate (ṁ)

The rate of mass flow, defined as ṁ = ρ * V_avg * A_c.

Bernoulli Equation

An approximate relation between pressure, velocity, and elevation, valid for steady, incompressible flow without significant friction.

Mechanical Energy

The form of energy convertible to work by an ideal mechanical device, including kinetic and potential energy.

Efficiency

The ratio of useful output energy to the input energy in a process, often expressed as a percentage.

Kinetic Energy Correction Factor (α)

A factor that accounts for differences in kinetic energy calculations based on average versus actual velocity profiles.

Hydraulic Grade Line (HGL)

A graphical representation of the pressure head in a fluid system, indicating the potential energy available at various points.

Energy Grade Line (EGL)

A graph that represents the total mechanical energy (HGL plus kinetic energy head) in a fluid flow system.

Flow Work (P/ρ)

The work associated with moving fluid into or out of a control volume, expressed per unit mass.