Nonequilibrium phase transitions in a jet of highly superheated water

Results are given of an experimental study into the dependence of integral and local characteristics of hot water flow on the value of superheating and on the kinetics of boiling in this water. Abrupt variations are revealed of parameters of a jet of boiling water such as the reactive force, the jet cone angle, and the rate of nucleation of vapor bubbles in the jet. Abrupt variations of modes of jet flow are treated as nonequilibrium phase transitions. This enables one to invoke model concepts of generation of $1/f$ fluctuations under conditions of nonequilibrium phase transitions in open systems. The inversely proportional dependence of power spectra of oscillation on frequency ($1/f$ fluctuations) in a jet of highly superheated water is found experimentally both under laboratory conditions and in a commercial-scale steam generator. Characteristic scales are discussed for reducing the experimental results for reactive force to dimensionless form.