Flashgass

Flashgass is a term encountered in some engineering and science fiction contexts to describe the rapid production of gaseous material following a sudden change in pressure or temperature in a liquid system. The concept resembles flash evaporation, where a liquid exposed to a rapid depressurization or heating undergoes instantaneous vaporization, producing a transient plume of gas and dynamic two-phase flow.

Mechanisms typically involve sudden pressure drop in a sealed or partially filled vessel containing a volatile liquid. If the liquid is near its boiling point or contains dissolved gases, the abrupt change can drive part of the liquid into the gas phase almost instantaneously. The resulting gas may be a single component or a mixture, and its properties depend on temperature, pressure, and composition.

Implications for design and safety include potential flow instabilities, pressure surges, and increased mass flow through vents. In industrial settings, similar effects are managed with controlled depressurization, relief devices, and proper vent sizing to limit overpressure and thermal shock. In fiction, flashgass is sometimes used as a mechanism for sudden gas release or propulsion.

Usage note: Flashgass is not a widely standardized term in mainstream journals. It appears mainly in informal engineering discussions or speculative contexts, and its precise meaning can vary depending on the author.