Aerogels with a density of 4.2−22.8 kg/m 3 were obtained from bacterial cellulose synthesized under static and dynamic cultivation conditions on a molasses medium. The strength properties and porous structure of the aerogels strongly depended on their density. With an aerogel density of 22.8 kg/m 3 , the modulus of elasticity at 80% compression of the sample was 0.1 MPa. The decrease in the density of aerogels led to an increase in the pore sizes ranging from 20 to 1000 μm and a decrease in the modulus of elasticity. These characteristics were more pronounced in aerogels obtained from bacterial cellulose under static cultivation conditions. The aerogels had a low coefficient of thermal conductivity (0.0257 W m −1 °C−1 ), which is comparable to the thermal conductivity of air, and moderate thermal stability because the degradation processes of the aerogels began at 237 °C. The aerogels obtained from bacterial cellulose had high sound absorption coefficients in the frequency range of 200−5000 Hz, which makes it possible to use the aerogels as heat-and sound-insulating materials.

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The paper presents a procedure for gas-dynamic analysis of processes in the air-gas channel of a small-sized two-stroke combustion engine. All steps are described. At the first stage a three-dimensional model of the interior space of the air-gas channel of a piston small-power engine was built; this model was split into nine different volumes according to the methodology of volumes partition for different kinds of grids application, which is provided in source materials. At the second stage all required sizes and types of finite elements were set for the correct operation of functions of resplitting and layer-by-layer re-formation of a grid in the cylinder volume and in the sub piston area. At the third stage all the necessary settings in the CFD-code ANSYS Fluent were made. Such as a transient simulation method, a turbulence model, parameters of mixture formation and fuel evaporation process, setup of intersection zones of the grid, setup of permeability of the boundaries between the calculated areas, setup of grid re-formation parameters, motion parameters of the piston and other moving elements of the simulated engine were introduced, setup of parameters and characteristics of the fuel injection process. User Defined Function (UDF) was used to set the rotation of the crankshaft. The calculations found fields of distribution of the basic parameters in the air-gas channel of the small-sized combustion engine, such as pressure, temperature, speed and composition of the working body. According to the simulation results power and fuel efficiency of the small-sized enginewere calculated.