Influence of Heat Transfer on Decreasing Intensity of a Spherical Explosion in Aqueous Foam

2019 ◽  
Vol 54 (7) ◽  
pp. 970-977 ◽  
Author(s):  
R. Kh. Bolotnova ◽  
E. F. Gainullina
Keyword(s):  
Heat Transfer ◽  
Aqueous Foam ◽  
Spherical Explosion

The Numerical Modeling of Spherical Explosion in the Foam

2016 ◽  
Vol 11 (1) ◽  
pp. 60-65 ◽  
Author(s):  
R.Kh. Bolotnova ◽  
E.F. Gainullina
Keyword(s):  
Shock Wave ◽  
Numerical Modeling ◽  
Initial Pressure ◽  
Water Volume ◽  
Symmetric Model ◽  
Two Phase ◽  
Experimental Conditions ◽  
Initial Water ◽  
Aqueous Foam ◽  
Spherical Explosion

The spherical explosion propagation process in aqueous foam with the initial water volume content α10=0.0083 corresponding to the experimental conditions is analyzed numerically. The solution method is based on the one-dimensional two-temperature spherically symmetric model for two-phase gas-liquid mixture. The numerical simulation is built by the shock capturing method and movable Lagrangian grids. The amplitude and the width of the initial pressure pulse are found from the amount of experimental explosive energy. The numerical modeling results are compared to the real experiment. It’s shown, that the foam compression in the shock wave leads to the significant decrease in velocity and in amplitude of the shock wave.

scholarly journals Freeze and Frost Protection with Aqueous Foam— Foam Development

1999 ◽  
Vol 9 (4) ◽  
pp. 661-669 ◽  
Author(s):  
Christopher Y. Choi ◽  
Werner Zimmt ◽  
Gene Giacomelli
Keyword(s):  
Heat Transfer ◽  
Physical Properties ◽  
Radiative Heat ◽  
Weather Conditions ◽  
Long Term Stability ◽  
Aqueous Foam ◽  
Foam Generation ◽  
Frost Protection ◽  
And Performance

Aqueous foam was developed to serve as a barrier to conductive, convective, and radiative heat transfer. Through the use of a bulking agent, the physical properties of gelatin-based foam were more stable, adhesive, biodegradable, and long lasting. The phytotoxicity, possible environmental hazard and removal of the foam were also considered. Resistance to freezing-thawing, heating-evaporation, and wind were evaluated. Studies to determine the foam's long-term stability under field weather conditions were completed. The handling and performance characteristics of the foam necessary for development of this application were determined. Factors that affect the physical properties and the utilization of the foam were quantified. These included the proportions of the foam components, the mixing temperature of the prefoam solution, the application temperature, and the rate of foam generation. The newly developed foam might be ideal for freeze and frost protection in agriculture.

Modeling of the spherical explosion attenuation process using aqueous foam

2019 ◽  
Vol 14 (2) ◽  
pp. 108-114
Author(s):  
R.Kh. Bolotnova ◽  
E.F. Gainullina ◽  
E.A. Nurislamova
Keyword(s):  
Shock Wave ◽  
Numerical Solution ◽  
Volume Fraction ◽  
Strong Shock ◽  
Liquid Volume ◽  
Contact Heat ◽  
Liquid Volume Fraction ◽  
Aqueous Foam ◽  
Spherical Explosion ◽  
Droplet Mixture

The two-phase model of dry aqueous foam dynamic behavior under the strong shock wave influence is presented under assumption that the foam structure under shock loading is destroyed into a suspension of monodispersed microdrops with the formation of a gas-droplet mixture. The system of equations for the model of aqueous foam includes the laws of conservation of mass, momentum and energy for each phase in accordance with the single-pressure, two-speed, two-temperature approximations in a three-dimensional formulation, taking into account the Schiller–Naumann interfacial drag force and the Ranz–Marshall interfacial contact heat transfer. The thermodynamic properties of air and water forming a gas-droplet mixture are described by the Peng–Robinson and Mie–Grueneisen equations of state. The presence of non-uniform process in height of aqueous foam syneresis, which is due to gravitational forces, is taken into account by setting the distribution of the liquid volume fraction in the foam. An additional consideration of the syneresis process during calculating the intensity of interphase drag forces according to the Schiller–Naumann model was controlled by introducing the parameter depending on the spatial distribution of the initial liquid volume fraction of the foam. The spherical explosion is modeled in the form of the shock wave pulse whose energy coincided with the charge energy of the HE used in the experiments. The problem numerical solution is implemented using the OpenFOAM free software package based on the two-step PIMPLE computational algorithm. The numerical solution of the problem, obtained on the basis of the proposed gas-droplet mixture model, is in satisfactory agreement with the experimental data on a spherical explosion in aqueous foam. The analysis of the spherical shock wave dynamics while its propagation through aqueous foam is given. The causes of the significant decrease in the amplitude and velocity shock waves propagation in the medium under study are investigated.

Heat transfer from in-line tube bundles to downward aqueous foam flow

2009 ◽  
Author(s):  
J. Gylys ◽  
S. Sinkunas ◽  
T. Zdankus ◽  
R. Jonynas ◽  
R. Maladauskas
Keyword(s):  
Heat Transfer ◽  
Foam Flow ◽  
Aqueous Foam ◽  
Tube Bundles
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