Application of computational gas dynamics methods for calculating losses during rotation of solids in low vacuum conditions

On the basis of a mathematical model with distributed parameters, a method for determining aerodynamic losses during high-frequency rotation of a flywheel accumulator is developed. The power of losses due to friction of the rotor against the air is determined as a function of the pressure in the chamber. A comparative analysis of the aerodynamic losses under low vacuum conditions at various pressures of the working medium and the data obtained on the basis of empirical dependences and presented in the scientific literature on this topic is carried out. The maximum difference between the loss power values is no more than 25%. The data deviation decreases as the pressure in the chamber decreases.

Сalculated analysis of the influence of operation and design factors on the parameters of oxygen-hydrogen low-thrust rocket engines

The paper presents the results of calculating thermodynamic and thermophysical properties of the combustion products of gaseous oxygen-hydrogen fuel according to the ideal LRE model taking into account the phase state of the components, as well as the parameters of a low-thrust engine according to the model of computational gas dynamics to ensure the selection of operation and design factors that define the design of a thruster for advanced aerospace objects. It is shown that ideal models can be used for the selection of some parameters, such as: the excess oxidant ratio, the pressure in the combustion chamber, the geometric degree of area expansion ratio. High-level computational gas dynamics models need to be used for the selection of some of the parameters of the engine to be designed, such as: design parameters of the propellant injection pattern, reduced length of the combustion chamber and some others. Air specific impulse was used as the selection criterion. The obtained calculation data allow one to choose the main parameters of the engine being designed with account for real processes in the combustion chamber and the nozzle of the engine.