Fluid mechanics
Fluid mechanics studies liquids and gases at rest and in motion, including the forces, energy, and transport involved in their behavior.
Continuum mechanics: The study of materials modeled as continuously distributed matter rather than collections of discrete particles. Fluid mechanics applies continuum models to represent density, velocity, and stress at each point.
Bernoulli's principle: A relation among pressure, speed, and elevation along a streamline in steady, incompressible, inviscid flow. It describes how pressure and speed trade off in an idealized moving fluid.
Aerodynamics: The study of air motion and the forces it exerts on bodies. It applies fluid mechanics to lift, drag, aircraft, and other bodies moving through air.
Solid mechanics: The study of how solid materials deform and respond to forces. It emphasizes shape changes and stress in solids rather than continuous flow.
Archimedes: An ancient Greek mathematician and engineer whose work established foundational principles of hydrostatics. His buoyancy principle remains a basic result for fluids in gravitational fields.
Pressure: The normal force exerted per unit area at a point in a material. Pressure differences drive fluid motion and transmit forces through fluids.
Reynolds number: A dimensionless ratio of inertial forces to viscous forces in a flow. It helps predict whether a flow is dominated by smooth layering or strong mixing.
Hydraulics: The engineering use of liquids to transmit force and perform work. It uses pressure and flow principles in pumps, pipes, and hydraulic machinery.
Kinetic theory: A molecular account of matter that derives macroscopic properties from particle motion and collisions. It resolves fluids into molecules, while continuum fluid mechanics treats them as smooth fields.
Blaise Pascal: A seventeenth-century French mathematician and physicist who studied pressure in fluids. Pascal's principle describes how pressure changes applied to a confined fluid are transmitted.