airfluid

Airfluid is a term used in science and engineering to describe situations in which air interacts with another fluid or particulate medium in a way that affects the behavior of the system. It is not a formal field, but a cross‑disciplinary concept used in modeling, design, and analysis of processes that involve air and a second phase.

In fluid dynamics, the air-fluid approximation treats air as a continuous phase. Depending on the regime, air may be modeled as incompressible or compressible and is typically coupled to a second phase such as a liquid, another gas, or solid particles. Solutions commonly rely on the Navier–Stokes equations, with turbulence modeling and multiphase interactions incorporated as needed.

A well-known application is the air-fluidized bed, where air is forced upward through a perforated distributor to suspend granular material. The resulting fluid‑like state reduces friction and enables efficient mixing, heat transfer, coating, or drying. Design and operation depend on factors such as superficial air velocity, particle size, density differences, and bed porosity.

Other uses of the term occur in computational simulations of air flows around liquids or solids, where the air is treated as a fluid that interacts with a second phase. In environmental and HVAC engineering, air-fluid considerations arise when analyzing exchanges between air and porous or liquid media.

Overall, airfluid describes the interplay between air and another phase within a fluid‑dynamic or multiphase context, often requiring interdisciplinary modeling approaches. See also fluid dynamics, multiphase flow, fluidized bed, aerodynamics.