卷 109, 编号 1 (2020)

The paper examines the problem of definition of the computational domain of the gasflow part at numerical simulation (RANS-approach) of gas flow in the low-flow stage of a centrifugal compressor at conditional flow rate Ф = 0.008. Several variations of replacing the design assembly of the flow part of the simulation stage with a gasdynamic model are considered: main working path of the stage; main working path of the stage taking into account the inlet area (inlet pipe and cowling); main working path of the stage taking into account the adjacent areas with full and partial connection with the gasflow part; main working path of the stage taking into account the friction surfaces of the stage rotor hub. It is shown that in case of axial suction into the stage the inlet pipe and cowling don’t significantly affect the parameter profile in front of the stage rotor and the gasdynamic characteristics of the stage. Modeling without areas adjacent to the path gives unsatisfactory quantitative and qualitative results. The most relevant option to take into account the losses of disk friction and leaks is a full twoway connection of adjacent areas with the flow part along the stage rotor disks, because when connecting only at the outlet of the stage rotor, the friction and leak losses are simulated, but the effect on the flow in the stage rotor is not taken into account. In some cases, it is important to consider the additional areas involved in friction losses.

The article deals with the choice of credit policy of an industrial enterprise. The influence of the chosen credit policy on the performance of an industrial enterprise is analyzed. A variant of implementing a conservative credit policy to reduce the risks of working with debtors is considered.

The paper deals with the investigation of the effect of the degree of milk protein coagulation on cultured milk ice cream quality indices (mixture viscosity, heat stability, shape stability and overrun). It was defined that the capability of mixture to be saturated with air decreased as its acidity increased because of the increase of the protein coagulation degree. Due to this the capability of protein to stabilize the air phase decreased. The positive effect of the process and the degree of protein coagulation on the product resistivity to thawing was proved experimentally; it was due to the product dense consistency and air low content.