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The effect of polymer additives on the growth of vapour bubbles in an infinite volume of superheated fluid was analysed in part 1 of the present paper. The second part discusses the reasons for the experimentally observed qualitatively different (with respect to a pure solvent) changes in the heat transfer coefficient in bubble boiling of polymer solutions with different macromolecule content. An explanation is suggested for the phenomenon of heat transfer enhancement in boiling of diluted solutions of high polymers with a concentration of about 0.01%.

The authors provide the state-of-the-art of theoretical studies concerned with local hyperthermia.

A comparison is made between the autowave processes of self-propagating high-temperature synthesis (SHS), conbustion of pyrotechnic composititions, and self-propagating synthesis in organic mixtures. It is shown that autowave modes in organic mixtures involve a variation in the electrophysical properties of a composition. Studying the latter allows one to determine the stages of microkinetic transformations based on the results of dynamic investigations of the self-propagating synthesis.

Heat/mass transfer and the dynamics of bubbles in a high-polymer solution exposed to ultrasonic agitation are investigated. An exact solution of the problem is found on the basis of which main features of the oscillations of bubbles are analysed with account taken of the relaxational properties of the carrying phase.

Free oscillations of bubbles in high-polymer solutions with viscoelastic properties are under investigation. Within the framework of the non-isothermal hereditary model of a liquid phase, an equation for the natural frequency of inclusion was derived, taking into account the effects of the interphase heat and mass transfer, diffusion and temperature non-equilibrium state of the vapour-gas mixture and of the liquid compressibility. A numerical analysis of the damping of free pulsations in a wide temperature range was conducted; the effect and specific features of the rheological factor were investigated.

The present paper is devoted to de3velopment and testing of an active vibration system. The system is intended for providing efficient motion of a piston in a hydraulic channel for creation of shocks and periodic vibrations in a low frequency range by means of the ER-valves based on an electrosensitive working me dium, i.e. electrorheological fluids. The latter manifests the electrorheological (ER) effect, i.e. a reversible change in the rheological characteristics of weak-conducting disperse compositions in the presence of constant and alternating electric fields. As a result of the experimental study of the dependence of viscoelastic properties of the ER-fluid on the magnitude and type of an electric field, the optimum dimensions of the vibrator and the its valves characteristics of the optimal electrical signal are determined. For control of an ER- vibrator having several valves we have designed a special type of a high-voltage two-channel impulse generator. Experiments were conducted at the frequencies ranged from 1- 10 Hz. It has been shown, that a peak force made 70% of the static force exercised by the vibrator rod. A phase shift between the input voltage and the load acceleration was less than 45 degree(s)C which allowed servocontrol and use of the vibrator for attendant operations. It was noted that a response of the vibrator to a stepwise signal has a delay only of several milliseconds.

A knowledge of the rheological properties of a composition as a function of conversion degree and temperature as well as macrokinetics of polymerization and heat release processes is necessary to make thermal and hydraulic calculations of a chemical molding process. A space-time separation of thermochemical (reservoir) and thermohydrodynamics (channel) stages is proposed to find rheokinetics and macrokinetics of a reactive fluid. The essence of their separation method is as follows. A test medium is placed into a thermostating cylinder of a charging chamber where it is maintained for a certain period of time to attain a prescribed curing degree. Then the fluid is pumped from the cylinder with an assigned velocity via an independently thermostating capillary. Tests made at different delay times (different curing degree) and at a fixed temperature of the charging chamber enable one to obtain the viscosity of a curing fluid as a function of conversion degree. Tests were made with the following composition: epoxy-diamine resin and curing agents such as metaphenilendiamine. The experimental set-up was composed of the independently thermostated reservoir and channel. The performance parameters were chosen in a special manner.

The propagation of finite-amplitude waves along a vibrating capillary jet is studied. The standing wave equation is derived.

Measurements are made of the average and pulsation velocities, the energy spectra, and the coefficients of turbulent diffusion during the flow of submerged jets of water and solutions of polyethylene oxide, Na-CMC, and guar gum.

The results of a theoretical and experimental investigation of the nonstationary mass exchange of a cone in a nonlinearly viscous fluid flow are presented. The amplitude-frequency characteristics of an electrodiffusion anemometer are plotted from the results obtained.

A study is made of the nonisothermal motion of a rheologically complex fluid in a plane-parallel channel in the case of boundary conditions of the third kind on the outer surfaces of the channel walls and with allowance for the dissipation of mechanical energy and temperature dependence of the coefficients. A qualitative investigation of the problem is made for arbitrary temperature dependence of the yield. Special cases are considered: flow of linear viscoplastic medium and a “power-law” medium with abrupt change with the temperature of the yield point and consistency. It is shown that under certain conditions several different flow regimes can be realized simultaneously in the channel and the change in the flow rate of the medium in a channel with varying temperature of the surrounding medium can exhibit hysteresis.

Although the mathematical description of convective heat transfer in conjugated formulation has found the general use to date, only a few of the publications present calculations for nonlinear-viscous ‘ power-law ’ fluids. But even these lack a general analysis of the effect of the rheological factor on heat transfer. The present paper deals with the study of the conjugated heat transfer problems for nonlinear viscoplastic fluid flows in plane-parallel channels. Basic criteria of the conjugated problems are established. An analysis is made of the possible simplifications which can be incorporated into the mathematical formulation of the problem depending on the relationship between the properties of the fluid and the channel wall material.

An equation has been theoretically derived for the effective thermal conductivity of a medium with anisodiametric particles. The case of the thermal conductivity of particles being much in excess of that of the binding medium is analyzed in detail. The possibility is shown for the particle shape parameters to be determined from the dependence of the effective thermal conductivity on the filler volume fraction. The effective thermal conductivity of solutions filled with metallic powders differing in nature and dispersivity has been studied experimentally. The predicted results agree satisfactorily with the experimental data.

Dynamic processes are studied in media with softly and hardly internal destroyable configurations. A method is examined for the measurement of properties of media with spatial separation of the chemical transformation stages and thermal hydrodynamic measurements.

Effects of relaxational diffusion during rapid evaporation of a solvent from a polymer solution taking place as a result of a thermal shock from the side of the free surface of the liquid are investigated. It is shown that, as a result of diffusional resistance to evaporation, a polymer-enriched layer is formed in the vicinity of the phase interface that can stabilize substantially the shape of the phase interface.