Bearing cavity ventilation design method of aero-engine

Abstract

The invention relates to a bearing cavity ventilating design method of an aero-engine and fundamental assumption of throttling and ventilating bearing cavity of the aero-engine, a method for calculating pressure and flow of a throttling hole, and a cavity pressure calculating procedure. Firstly, boundary parameters of the bearing cavity are obtained and repeated iteration united algorithm is performed on cavity pressure of an air system and an accessory cartridge receiver to obtain the pressure of the bearing cavity. Secondly, assumption is performed as follows. Only steady-state conditions of the aero-engine undergo calculation. The total pressure of the bearing cavity in a steady sate is assumed to stagnation pressure. A flowing process of air currents passing through the throttling hole from the bearing cavity is assumed to be an isoenergetic isentropic process. An oil returning pump of the bearing cavity neglects influences on the cavity pressure and then the throttling and ventilating bearing cavity of the aero-engine is solved. The bearing cavity ventilating design method of the aero-engine has the advantages that calculating data on the pressure of the bearing cavity of a throttling and ventilating aero-engine lubricating system can be obtained in a flight envelope and design of throttling and ventilating systems of lubricating systems of power of a military aero-engine, a civil plane, a gas turbine and a boat can be guided and the application prospect is wide.

Description

technical field [0001] The invention relates to the field of lubricating system design of an aero-engine, in particular to a method for designing the ventilation of an aero-engine bearing chamber. Background technique [0002] Aeroengine lubrication system consists of oil supply system, oil return system and ventilation system. Among them, the ventilation system includes the main shaft sealing device, ventilation pipeline, centrifugal ventilator, high-altitude valve, etc. The design goal of the ventilation system is to ensure that the bearing cavity pressure in the engine flight envelope is stable within a certain range. With the increasing flight altitude required by aircraft to complete tasks, the throttling ventilation structure of the aero-engine lubrication system ventilation system has been widely used in engine design. Throttle ventilation is the most common ventilation method for the bearing cavity of the engine with grate tooth seal structure. Its purpose is that w...

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Problems solved by technology

[0005] Therefore, the bearing cavity pressure of the throttling and ventilated engine lubrication system cannot be obtained by calculation at the beginning of the design. The ground state point data can only be obtained through the ground test run, and any state point data of the high-altitude state cannot be obtained through test run or calculation.

It is also impossible to obtain important data such as whether the seal of the main shaft of the engine is reversed within the flight envelope, which seriously restricts the design and verification of the engine lubrication system and the seal of the main bearing cavity

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