The Physics of Fluids: Hydraulic Systems and Buoyancy

Vocabulary flashcards covering pressure types, hydraulic principles, and fundamental equations of fluid mechanics based on lecture notes.

Pressure

The continuous physical force applied to or against an object by something in contact with it; scientifically, the force exerted perpendicular to a surface divided by the total area ($P = \frac{F}{A}$).

Pascals (Pa)

One of the units used to measure pressure, along with pounds per square inch (psi).

Atmospheric Pressure

The pressure of the air around us, with a standard value of $101.3\,kPa$.

Gauge Pressure

Pressure measured relative to atmospheric pressure; it represents pressure above the atmospheric level.

Absolute Pressure

Total pressure measured from a zero reference, calculated as the sum of $\text{Gauge} + \text{Atmospheric}$ pressure.

Differential Pressure

The difference in pressure between two points, represented by the formula $\Delta P = P_1 - P_2$.

Hydrostatic Pressure

The pressure in a fluid due to its depth ($h$), calculated using the formula $\rho gh$ (Density $\times$ Gravity $\times$ Height).

Pascal’s Principle

The principle stating that pressure applied to a confined liquid is transmitted equally and undiminished in all directions throughout the liquid and to the walls of its container.

Hydraulic System

A system using fluid principles to enhance machines, where force applied to a smaller area is transmitted through a confined liquid to a larger surface area to produce a greater output force.

Continuity Equation

A principle stating that for an incompressible fluid, the mass flow rate remains constant throughout a streamline (what flows in must equal what flows out).

Bernoulli’s Principle

The fundamental law describing the relationship between fluid speed and pressure: as fluid velocity increases, pressure decreases.

Navier-Stokes Equations

Partial differential equations that model how velocity, pressure, temperature, and density of a moving viscous fluid are interrelated across space and time.

Aerospace Engineering

A field that applies Bernoulli’s equation and Navier-Stokes equations to optimize lift, reduce drag, and improve fuel efficiency in aircraft and spacecraft.

Civil Engineering

A field that utilizes fluid mechanics for the design of pipe systems and hydraulic networks, focusing on flow rate calculations, pressure management, and turbulence control.