Shumilov

pp. 51-75

pp. 24-42

pp.139-161

The article considers process fluids, which are presently applied to aviation hydraulic systems (AHS) in domestic and world practice. Aviation practice uses rather wide list of fluids. Based on the technical specification a designer makes the choice of specific fluid for the specific aircraft. Process fluids have to possess the specified properties presented in the article, namely: lubricating properties; stability of physical and chemical characteristics at operation and storage; low-temperature properties; acceptable congelation temperature; compatibility with materials of units and components of hydraulic systems; heat conductivity; high rigidity; minimum low coefficient of volume expansion; fire-explosion safety; low density. They should also have good dielectric properties, be good to resist to destruction of molecules, have good anticorrosion and anti-erosion properties, as well as not create conditions for emerging electro-kinetic erosion of spool-type and other precision devices, and a number of other properties.

Nowadays reduction of the mass of an aircraft’s rudder control system (RCS) still is an important problem for designers, which can be solved by structured design methods or selection of optimal parameters of control system’s different elements. It’s also essential not to degrade the required flight safety and reliability level and meet the demands of airworthiness (AP25), including the influence of the so-called “human factor” on the flight safety. That’s why, to reduce the mass of MCS, one can try to reduce the mass of each element; one has to deal with working levers and control-loading devices, remote signal transmission, rudder gears, energy supply systems and mass and geometry optimization system for several elements of RCS. This article provides analyses and necessary recommendations for designers on every of listed directions.

This article presents schema and constructions of hydraulic tanks of open and closed types used in passenger and maneuverable aircraft. The authors propose a technique of calculation of the necessary volume of fluid for hydraulic tanks of open and closed types; this method takes into account all flight regimes, including flights with a negative overload. The design procedure of the tank geometry which would have an optimal weight is also presented in the article, along with the scheme of open type tank pressurization with high-pressure dry air and reserve pressure boost from the cabin air-conditioner, the scheme of connection and design of the vent tank.