fluido

Fluido is a substance that deforms continuously when subjected to shear stress and is able to flow. Unlike solids, fluids do not retain a fixed shape and instead adapt to the contours of their container. In physics, fluids are typically treated as continua, meaning their properties can be described by fields that vary smoothly in space and time. Fluids include liquids and gases, and, in many contexts, plasmas are also treated as fluids under appropriate conditions.

Key properties of fluids include density (ρ), dynamic viscosity (μ), and kinematic viscosity (ν = μ/ρ). Fluids may also be compressible or effectively incompressible; liquids are often treated as incompressible, while gases show density changes with pressure and temperature. Surface tension is important for liquids, governing phenomena at interfaces. Temperature, pressure, and composition influence fluid properties and their flow behavior. The study of fluids considers both fluid statics, where flow velocity is zero, and fluid dynamics, where velocity fields drive motion.

Governing equations in classical fluid mechanics include the continuity equation for mass conservation, and the Navier–Stokes equations for momentum balance. For steady, inviscid flow, Bernoulli’s principle provides a simplified relation between pressure, velocity, and height. The Reynolds number characterizes the transition between laminar and turbulent flow.

Applications span hydraulics and civil engineering (pipes and ducts), aerospace and automotive engineering (airflow around bodies), meteorology and oceanography (weather systems and currents), and many industrial processes involving mixing, lubrication, or heat transfer.