Alexey Boldyrev

Kazan (Volga Region) Federal University · N.I. Lobachevsky Institute of Mathematics and Mechanics

Hydrostatic transmission is a system of speed variation of multi-drive vehicle. The use of volumetric flow divider as part of a hydrostatic transmission allows to expand the range of traction and dynamic regulation and to improve the technical characteristics of the vehicle, such as mobility (cross-country ability) and handling. The article present...

The article presents a new method for the comparative analysis of the effectiveness of a vapor-liquid compression cooling system and traditional solutions based on single-phase liquid and air cooling, while taking into account the combination of cooling capacity factors, the power expended on this, depending on the ambient temperature. As a result...

The article considers a mathematical model of hydrostatic transmission with an axial flow divider for a multi-drive vehicle during its maneuvering. The new method for controlling the energy parameters of the wheel drive by adjusting the angles of swash plates for each section of the axial flow divider depending on the radius of rotation of the mult...

The article describes the problem of maintaining the energy efficiency of modern heat transformers in off-design operating conditions. A structural scheme of the vapor compression cooling system and static mathematical model based on the equations of heat balance and heat transfer and modified in terms of additional accounting for the effect of out...

The transient dynamic characteristics of shell-and-tube multi-pass heat exchanger-evaporator of vapor compression cooling system are studied. Based on the balance of thermal power and the criterial heat transfer equations the mathematical model of the physical processes taking place in the heat exchanger-evaporator is compiled. The change in the co...

The use of an axial divider as a part of the hydrostatic transmission makes it possible to realize the torque regulation of the motorized wheel due to pressure dynamics without increasing the flow of working fluid and also to simplify the control system. This paper is concerned with mathematical modeling and dynamic analysis of an axial adjustable...

A mathematical model of cooling system with a vapor-liquid compression unit is presented. The modeling of dynamics of the parameters of the vapor compression system during the system start-up in the cooling mode was carried out. It is noted that with the accepted assumptions the evaporation and condensation temperatures stabilize fast enough: in th...

Offered in this article modification variant of quadratic High-Reynolds number k-ɛ turbulence model is intended for more accurate prediction of the local characteristics of pulsated separated turbulent flow of compressible gas in channel behind diaphragm at rather high values of Strouhal number. Correction functions C1 and κ values are determined a...

The work sets out the distinctive features of the method of gas-dynamic calculation of multistage centrifugal compressors for refrigerating machines running on a cycle of multi-stage compression of working fluid with its complete intercooling between the stages. The parameters of width of specific sections of the impellers, diffusers, and reverse g...

The article presents a mathematical model of volumetric type hydraulic drive controller that allows to calculate the parameters of forward and reverse motion. According to the results of simulation static characteristics of rod's speed and the force of the hydraulic cylinder rod were built and the influence of the angle of swash plate of the contro...

Conducted numerical research of static characteristics of the rotary gate valve at different angles of its deviation. for this purpose were set different values of pressure differential on the valve depending on which, was determined the mass flow and torque on valve axes. The mathematical model is provided by continuity equations, average on Reyno...

The motion of liquids and gases in technical devices rarely occurs without external disturbances that lead to the change of environment flow regimes and flow characteristics. Besides, a joint effect of disturbances on the flow is possible. The article describes the results of a three-dimensional numerical simulation of a separated turbulent flow of...

The numerical simulation method of turbulent flow in a running space of the working-stage in a centrifugal pump using the periodicity conditions has been formulated. The proposed method allows calculating the characteristic indices of one pump step at a lower computing resources cost. The comparison of the pump characteristics' calculation results...