Salimzhan A. Gafurov

Plastics are more and more frequently applied in the construction of hydraulic components and systems, and recently, in the building of microhydraulic assemblies. The basic unit of the microhydraulic systems is a micropump. It is an object which is quite difficult to design and manufacture, especially when using plastics. The paper is a presentation of challenges that must be met in the process of designing gear pumps, and, at the same time, of the theoretical grounds for the designing of those objects. The challenges include the geometry and the gears, the construction of the pump body, the hydraulics of the pump, and the material—the plastic of which the pump is made. The knowledge on those issues was applied to make and to successfully test a prototype of a micropump.

Today, this type of actuators as pneumatic muscles has wide application. Pneumatic muscle is a one-way actuator and has such advantages as the developed force, as well as speed. Pneumatic muscles, compared to pneumatic cylinders, have a non-linear structure that needs to be correctly identified. In this paper, we study the dynamic processes of pressure change in the working cavity of a pneumatic muscle in order to build a mathematical model, which can later be used to develop control systems, where the main actuator is pneumatic muscle. As well as in order to accurately describe and predict the geometric parameters of pneumatic muscles on pressure of compressed air in the working cavity.

Previous research has shown that aviation fuel pumps, which consist of a screw and centrifugal wheels are the most loaded units of the gas turbine engines. Thus a fuel pump is the key component that limits the reliability and endurance of the fuel system and, as a result, of the whole engine. This paper describes the results of CFD simulations of the process getting free gas to enter the combined pump. The CFD analysis has been used to calculate an unsteady three-dimensional viscous flow of multi-component fluid in the fuel pump. The calculations have been used to determine unsteady loads of fuel pump in different operating modes. To examine the efficiency of the CFD analysis, we conducted a series of experiments. The experimental results proved the accuracy of the numerical model. The results can help to develop measures for the reduction of dynamic loads in aviation fuel pumps in case where combined air is at entrance to pump.