Tweefase

Tweefase is a Dutch term used to describe systems or processes in which two distinct phases of matter are present simultaneously or in which a process involves two separate physical states. The concept is applied across disciplines such as physics, chemistry, and engineering, and is often used to describe both equilibrium states and dynamic processes.

Two-phase systems can involve different combinations of phases, such as immiscible liquids (for example water and oil), a gas and a liquid (such as steam and water), or a solid and a liquid (such as ice in water). In many contexts, the phases remain separable on the macroscopic scale, while in others, one phase may be dispersed as droplets or foams. The interfacial boundary between the phases governs phenomena such as mass transfer, heat transfer, and interfacial tension.

In engineering, two-phase flow refers to the simultaneous movement of two phases within a channel or vessel, typically a gas–liquid or liquid–liquid mixture. This leads to distinct flow regimes (for example bubbly, slug, or annular flow) that influence pressure drop, heat transfer, and overall process performance. Measurement and modeling of two-phase systems rely on approaches ranging from visual observation and sensors to theoretical and computational methods.

Typical applications appear in chemical and process engineering, oil and gas, power generation, refrigeration, and materials science. The broader concept of two-phase systems is related to multiphase flow and phase separation, and it contrasts with three-phase or single-phase systems in both theory and practice.