Complete adiabatic evaporation of highly superheated liquid jets.

Kurzfassung

A nozzle expansion into a vacuum chamber was used to investigate the evaporation of highly superheated liquid jets. The large molar specific heat of fluids with high molucular complexity - in this caseC 6 F 14- is responsible for the new phenomena reported here. A modelwas developed to describe the basic physical effects. A cubic equation of state was used to describe the thermodynamic properties of the fluid. The evaporation was modelled as a sonic deflagration followed by an axisymmetrie supersonic expansion. As in the case of hypersonic gas jets the final state is reached by a normal shock. Forsufficiently high temperatures and expansion ratios a complete adiabatic evaporation of the liquid was found. At even higher temperatures the liquid evaporates completely within a rarefaction discontinuity. The predictions of the model are in good agreement with the experimental results.