SIMULATION OF THE INTERACTION OF THE LIGHT AND DRY FOAM LIKE SYSTEM

A.V. Pantyukov1,2, E.A. Isaeva1, A.A. Isaeva1, D.A. Zimnyakov1 1. Yuri Gagarin Saratov State Technical University, Saratov, Russia

2. alex.pantukoff@yandex.ru

MODEL OF DRY FOAM LIKE SYSTEM We have already considered the possibility of using Kelvin cells to

model foams[3], but real structures have a more complex shape. Therefore, we are developing a different approach. Two-phase dry foam is used as a medium model (n1 = 1,4 – refractive index of the liquid phase, n2 = 1 – the refractive index of the gas).

Let's randomly distribute the coordinates of the cells centers in the volume. Let's make these points shift relative to the neighboring ones. The value of this offset depends on the distance between the points (1). Such relaxation occurs until the moment when the distance between all points is less than the one set by the program. After that, the program determines the neighboring centers of the cells. The faces are constructed in the form of equations of the tangent plane to the sphere between the centers, included the width of the channels. The width of the channels and the number of cells determine the volume fraction of the liquid in the medium. Cell radius (R) 132.14 µm, channel width 5.86 µm, system volume 243·109 µm3, number of cells 16886, liquid volume fraction – 6.4%.

SIMULATION OF LIGHT SCATTERING Light propagation in the medium is performed based on the

laws of geometric optics, since the cell sizes are much larger than the wavelength of laser radiation. At the entrance to the system, we simulate an incident light stream with a given number of rays inside. The rays enter the system at a right angle.

(1)

REFERENCES 1. A.M. Kraynik, D.A. Reinelt, Frank van Swol "Structure of random monodisperse foam" // Physical Review E 67, 031403 (2003); 2. E.B. Matzke, Am. J. Botany 33, 58 (1946); 3. A.A. Isaeva, E.A. Isaeva, A.V. Pantyukov, D.A. Zimnyakov "Simulation of radiative transfer in dispersive multiphase systems with supercritical fluidic components " // Proc. SPIE 11846, Saratov Fall Meeting 2020: Laser Physics, Photonic Technologies, and Molecular Modeling, 118460V (4 May 2021); 4. Д.А. Зимняков, С.А. Ювченко, Е.А. Исаева, А.А. Исаева, О.В. Ушакова «Анизотропия рассеяния света вспененными жидкостями» // Оптика и спектроскопия, 2018, том 125, вып. 5

CONCLUSION The presented interim results indicate the need to refine the

dry foam model. We see such a refinement in the addition of the possibility of

building cells of different sizes and a mechanism for controlling their mutual orientation.

INTRODUCTION The intermediate results of the development of a software package

for the analysis of the physical properties and structure of foamed media are presented. A model of the interaction of laser radiation with dry foam is developed, the discovered problems are described and methods for their further solution are proposed.

Figure 1. Distribution of the number of cell faces.

Figure 2. Ray trajectory projections.

Figure 3. Weak deviation of the ray path on parallel faces.

However, the value of light transmission in the experiment[4] is very different from the simulation results (experiment - 20%, model - 56%). The trajectory of many rays almost does not change. We think this is because the cell sizes are almost the same, and the orientation of the neighboring faces is absolutely parallel (Fig. 3).

𝑥𝑤 = 𝑥2 − 𝑥1 ∙ 𝐹

𝑦𝑤 = 𝑦2 − 𝑦1 ∙ 𝐹

𝑧𝑤 = 𝑧2 − 𝑧1 ∙ 𝐹

, 𝐹 =𝑅

3∙ 𝐻𝐿−𝑆,

where F performs the function of the repulsive force module, L – distance between cell centers, H and S are selected so that in a certain critical radius (Rcr) F = 0, Rcr depends on the number of cells in the volume.

We get statistics on the number of cell faces according to the our model and compare it with the paper [1]. This result indicates the acceptability of the described method.