Abstract (Invited)

Nonlinear Phenomena in Bubbly Liquids

V.Kedrinskii (Lavrentyev Institute of Hydrodynamics SB RAS, Novosibirsk, Russia)

e-mail: kedr@hydro.nsc.ru

A number of nonlinear problems of bubbly medium mechanics touched the state dynamics of cavitation zone behind a rarefaction wave front , features of formation and interactions of shock and rarefaction waves in passive and reactive bubbly systems including the experimental statements and mathematical models will be considered. In particular in a result of experimental studies of intensity dynamics of laser beam scattering the idea about two-phase state of real liq-uids was formulated. Using the conservation laws of gas dynamics and assumption that nonline-arity of processes is mainly determined by the bubble dynamics the two-phase mathematical model for average pressure and volumetric concentration of gas phase was suggested. It includes in evident form radius of bubbles and initial concentration of gas phase. The model turned out to be very effective for description of fine structure of shock waves , of cavitation development in real liquids contained microinhomogeneities and has allowed to make the analytical estimations for relaxation of tensile stresses as well as to formulate the conception of limit stresses permitted by cavitating liquids. The idea about two-phase state of real liquids was formulated. The experience shows that inhomogeneity of real liquid state and a physics of phenomena arising in reactive bubbly systems under shock wave loading are direct relevant to such essentially nonlinear phenomena as detonation of liquid explosives (bubble mechanism of reaction ignition), high-scale explosions of containers with liquefied combustible gas (cavitation processes) and bubbly detonation. The mechanisms of these phenomena turned out to be similar. They can be described by two-phase model supplied by an equation of chemical reaction kinetics and are interesting with view point of “acoustic laser” problems. Two examples will be discussed.

Section : 4