fluidas

Fluidas is a term found in Spanish and Portuguese that refers to substances with the property of flowing. In scientific usage, the related category is known in English as fluids, encompassing liquids, gases, and plasmas in appropriate frameworks. Fluids are characterized by their ability to deform continuously under shear stress and to flow, adapting to the shape of their container.

Key properties of fluídas include viscosity, density, and compressibility; surface tension; and, in many cases, temperature and composition-dependent behavior. Fluid behavior is governed by principles of fluid mechanics and fluid dynamics, with the motion described by equations that express conservation of mass, momentum, and energy. The Navier–Stokes equations provide a general description of viscous fluid motion, while the continuity equation expresses mass conservation. For ideal, incompressible flows, Bernoulli’s principle offers a simplified relation between pressure and velocity. The Reynolds number indicates the relative importance of inertial and viscous forces in a given flow.

Classification of fluídas covers Newtonian and non-Newtonian fluids, as well as incompressible and compressible fluids. Complex fluids include suspensions, emulsions, gels, and polymer solutions, which may exhibit non-Newtonian or viscoelastic behavior.

Applications of fluídas span hydraulics, aerodynamics, meteorology, oceanography, chemical engineering, and physiology, including blood flow in the circulatory system. The term fluido/fluida ultimately derives from Latin fluidus; fluídas is the feminine plural form in Spanish and Portuguese used to refer to fluids.