Explosion generation of microatomized liquid-drop aerosols and their evolution

The formation of a microatomized aerosol was investigated with the use of a model of an explosion atomizer based on a hydrodynamic shock tube with atomization through a clearance (nozzle). It is shown that the cavitation of the liquid subjected to atomization plays a great role in the production of a microatomized liquid-drop aerosol. A mathematical model describing the genesis of an aerosol cloud is proposed. The time of propagation of a compression wave in the liquid subjected to atomization and the time of its outflow from the atomizer were estimated, the size distribution of the aerosol particles was constructed, and the dependence of this distribution on the coagulation, evaporation, and precipitation of the aerosol particles was determined. A technique for undisturbed measurement of the genesis of an aerosol is described. Results of an experimental investigation of the dispersion parameters of an aerosol and the processes of formation and propagation of an aerosol cloud produced as a result of the explosion atomization of a liquid are presented.     

Ultrasonic effect on the penetration of the metallic melt into submicron particles and their agglomerates

Deagglomeration and wetting of submicron particles in a metal melt under ultrasonic exposure are considered based on the theory of acoustic cavitation and capillary phenomena. Basic dependences linking the exposure time with physicochemical properties of the particles and the melt, as well as with acoustic radiation characteristics, are found. The experimental and calculated times of ultrasonic treatment of the aluminum melt containing submicron aluminum oxide particles are compared, and a satisfactory agreement of results is found.     

Experimental Study of the Effect of Metal Nanopowders on the Decomposition of HMX,AP and AN

The effect of metal nanopowders (Al, Fe, W, Ni, Cu, and Cu‐Ni alloys) on the decomposition of energetic materials (HMX, AP, and AN) with DTA–TGA method was studied and it was found that the catalytic action appears in the case of Cu‐Ni nanopowders with the three studied energetic materials. The temperature of decomposition of energetic materials with the addition of metal nanopowders could be lowered by 82 °C for AN, 161 °C for AP, and 96 °C for HMX. The reaction mechanism of metal nanopowders enhancing the decomposition of energetic materials is discussed.     

Ignition of condensed material

Tomsk. Translated from Fizika Goreniya i Vzryva, Vol. 24, No, 3, pp. 39–41, May–June, 1988.     

On the construction of K-consistent difference schemes of gas dynamics

Previously it was found by the present authors that the use of non-classical equations of state in gas dynamic computations by Eulerian difference schemes may give rise to spurious oscillations of the numerical solution in the vicinity of contact discontinuities. Two accurate methods for elimination of these oscillations are proposed below. One of these methods is based on a new definition of the K-consistency of difference schemes. Another method makes use of difference approximations of an unsteady equation for pressure which is a well-known consequence of the Euler equations. The effectiveness of the methods proposed is illustrated by computational results.