Aero-engine oil leakage system design method
By identifying oil leak points and designing reasonable oil leak lines and ejectors, the problem of incomplete fuel discharge from the engine was solved, ensuring safe engine operation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- AVIC GUIYANG ENGINE DESIGN & RES INST
- Filing Date
- 2026-03-04
- Publication Date
- 2026-07-14
AI Technical Summary
The existing oil leakage system of aircraft engines is poorly designed, causing fuel to flow into the lubrication chamber when the engine is stopped, which affects the safe operation of the engine.
By identifying oil leak points, calculating the amount and pressure of the leak, and designing a unique oil leak pipeline layout and ejector, fuel is ensured to be discharged outside the engine. An oil leak tank is used to collect the fuel and prevent lubricating oil from entering the engine cavity.
It effectively removes fuel from the engine, prevents carbon buildup in the combustion chamber nozzles, and ensures safe engine operation.
Smart Images
Figure CN122389684A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of overall integrated design technology for aero-engines, and specifically to a design method for an aero-engine oil leakage system. Background Technology
[0002] The aircraft engine is the heart of an aircraft, providing the power required for flight. The fuel system is one of the most important systems in an aircraft engine, and the fuel leakage system is an important component of the aircraft engine fuel system. The aircraft engine fuel system mainly filters the incoming fuel, pressurizes the fuel, establishes the fuel pressure required by the fuel and actuation subsystems, completes the fuel metering in the main combustion chamber and afterburner, and completes the flow distribution of main fuel and afterburner fuel.
[0003] During engine operation, the fuel pumps in the fuel system rotate at high speed. Oil leakage may occur at the shaft end seals of each fuel pump during operation, which needs to be drained. After the engine stops, there is excess fuel in the main and auxiliary fuel lines after the main fuel distributor. If it is not drained in time, it may cause carbon buildup in the main and auxiliary fuel line nozzles of the combustion chamber, affecting engine starting ignition and operational safety.
[0004] Currently, engine oil leakage systems are generally designed based on experience. During the development of model series, there are cases where the oil leakage system is poorly designed and the layout of the oil leakage pipeline is not fully considered to ensure that the leaked oil can be discharged from the engine. This results in fuel in the oil leakage system flowing into the lubrication chamber through the accessories when the engine is stopped, affecting the engine's working safety.
[0005] Therefore, a design solution for an aero-engine oil leakage system that can fully discharge leaked oil outside the engine is needed to prevent carbon buildup in the main and auxiliary oil line nozzles of the combustion chamber and ensure normal engine operation. Summary of the Invention
[0006] To address the technical problem that existing technologies fail to adequately remove leaking oil from the engine, this invention provides a design method for an aircraft engine oil leakage system, comprising the following: The components of an aircraft engine oil leak system are identified, including a main fuel distributor, a leak tank, an ejector, and leak lines. Identify the location and components of all oil leaks in the aircraft engine; the locations of the oil leaks include engine accessories, main pipes and pipelines, and other locations; the components of the oil leaks include the fuel centrifugal booster pump, main pump-control unit, main fuel distributor, nozzle fuel source pump, and afterburner fuel pump; all oil leaks are connected to the oil tank via leak pipes. Obtain the oil leakage amount Q and oil leakage point pressure P at each oil leakage point in both working and non-working states, and determine the calculated values of the oil leakage amount Q and oil leakage point pressure P at each oil leakage point. Based on the calculated values of the oil leakage amount Q and the oil leakage pressure P at each oil leakage point, the characteristics of the oil leakage pipe are determined, including the pipe diameter d and the pipe strength. Based on the location and components of each oil leak point, the calculated values of the oil leakage amount Q and the oil leakage pressure P at each oil leak point, and the characteristics of the oil leak pipe, the layout of the oil leak pipe is carried out, and the laying location of the oil leak pipe is determined. Based on fluid dynamics simulation calculations, the characteristics and location of the ejector are determined; By obtaining the engine's maintenance requirements, external contour design requirements, and the external contour of the aircraft engine compartment, and combining the calculated values of the oil leakage amount Q and the oil leakage pressure P at each of the aforementioned oil leakage points, the characteristics and location of the oil leakage tank are determined, and the design of the aero-engine oil leakage system is completed.
[0007] Furthermore, the method for determining the calculated values of the oil leakage amount Q and the oil leakage pressure P at each leakage point is as follows: The oil leakage amount Q and oil leakage point pressure P of each oil leakage point are compared in both working and non-working states. The oil leakage amount Q and oil leakage point pressure P with the larger value in the two states are used as the corresponding calculated values.
[0008] Furthermore, the method for determining the pipe diameter d includes the following: Obtain the outlet pressure P0 of the ejector drain pipe, and calculate the pipeline pressure difference ΔP based on the calculated value of the oil leakage point pressure P at each of the oil leakage points. Based on the calculated oil leakage amount Q at each leak point, and combined with the pipeline pressure difference ΔP, the flow area A of the leaking pipeline is calculated. The pipe diameter d is determined based on the flow area A of the leaking pipe.
[0009] Furthermore, the expression for calculating the flow area A of the leaking pipeline is: ; in, The amount of oil leakage in the leaking pipeline is the sum of the oil leakage amounts Q at all leak points in the pipeline. Indicates the fuel flow coefficient of the pipeline; This indicates the density of the fuel.
[0010] Furthermore, the method for determining the pipeline strength is as follows: based on the calculated value of the oil leakage point pressure P at each of the oil leakage points, simulation calculations are performed to obtain the pipeline strength.
[0011] Furthermore, the location of the oil leakage pipeline is as follows: the oil leakage pipeline is laid below all the oil leakage points and above the oil leakage tank.
[0012] Furthermore, the determination of the features and location of the ejector includes the following: Based on fluid dynamics simulation calculations, the characteristics of the ejector are determined, including the structure and main parameters of the ejector. The gas extraction location is determined based on the structure of the ejector; The position of the ejector is determined based on the structure of the ejector and the requirements of the engine outline.
[0013] Furthermore, the determination of the characteristics and location of the oil leak tank includes the following: Based on the calculated oil leakage amount Q at each of the aforementioned oil leakage points and the engine maintenance requirements, the volume V of the oil leakage tank is determined. The strength of the oil leak tank is determined based on the calculated value of the oil leak pressure P at each of the aforementioned oil leak points. The outline of the oil leak tank is determined based on the engine outer contour design requirements and the outline of the aircraft engine compartment. The location of the oil leak tank is determined based on its outer contour and the location of the oil leak pipeline.
[0014] Furthermore, the oil leak tank is located at the lowest point of the engine accessories, lower than other accessories and oil leak lines.
[0015] The beneficial effects of this invention are as follows: This invention identifies oil leak points, obtains the amount and pressure of oil leaks in both working and non-working states, determines the calculation of the amount and pressure of oil leaks, identifies the characteristics of the oil leak pipeline, lays out the oil leak pipeline, and determines the laying location of the oil leak pipeline, thereby determining the characteristics and location of the ejector and the oil leak tank, and completing the design of the aero-engine oil leak system; The aero-engine oil leak system designed by this invention, through its unique oil leak pipeline layout, ejector, and oil leak tank design, can discharge oil leaks from various engine accessories and fuel in the fuel mains through the ejector to the outside of the engine; When the engine is parked, the fuel in the oil leak system can flow into the oil leak tank, preventing fuel lubrication from entering the cavity and ensuring engine operating safety. Attached Figure Description
[0016] Figure 1 This is a flowchart of the design method for an aircraft engine oil leakage system provided by the present invention; Figure 2 This is a design logic diagram of an aircraft engine oil leakage system provided by the present invention. Detailed Implementation
[0017] The technical solution of the present invention is further described below, but the scope of protection is not limited to what is described.
[0018] This invention provides a design method for an aircraft engine oil leakage system, such as... Figure 1 , Figure 2 As shown, it includes the following: Step S100: Determine the components of the aircraft engine oil leakage system, including the main fuel distributor, oil tank, ejector, and oil leakage pipeline. Step S200: Identify the location and components of all oil leak points in the aircraft engine; the locations of the oil leak points include engine accessories, main pipes and pipelines, and other locations; the components of the oil leak points include the fuel centrifugal booster pump, main pump-control unit, main fuel distributor, nozzle fuel source pump, and afterburner fuel pump; all oil leak points are connected to the oil leak tank through oil leak pipes. Step S300: Obtain the oil leakage amount Q and oil leakage point pressure P of each oil leakage point in the working state and non-working state, and determine the calculated values of the oil leakage amount Q and oil leakage point pressure P of each oil leakage point. The method for determining the calculated values of the oil leakage amount Q and the oil leakage pressure P at each leakage point is as follows: The oil leakage amount Q and oil leakage point pressure P of each oil leakage point are compared in both working and non-working states. The oil leakage amount Q and oil leakage point pressure P with the larger value in the two states are used as the corresponding calculated values.
[0019] In operation, the oil leakage amount Q at each leakage point is represented as Qi. 工 i represents the oil leak point; the oil leak point pressure P at each of the aforementioned oil leak points is denoted as Pi. 工 ; In the non-operating state, the oil leakage amount Q at each leakage point is represented as Qi. 非工 The oil leak pressure P at each leak point is denoted as Pi. 非工 ; When determining the calculated values of the oil leakage amount Q and the oil leakage pressure P at each of the aforementioned leak points, compare them with Qi. 工 and Qi 非工 Pi 工 And Pi 非工 The larger values are selected as the calculated values of the oil leakage amount Q and the oil leakage pressure P at each leak point.
[0020] Step S400: Based on the calculated values of the oil leakage amount Q and the oil leakage pressure P at each oil leakage point, determine the characteristics of the oil leakage pipe, wherein the characteristics of the oil leakage pipe include the pipe diameter d and the pipe strength. The method for determining the pipe diameter d includes the following: Obtain the outlet pressure P0 of the ejector drain pipe, and calculate the pipeline pressure difference ΔP based on the calculated value of the oil leakage point pressure P at each of the oil leakage points. Based on the calculated oil leakage amount Q at each leak point, and combined with the pipeline pressure difference ΔP, the flow area A of the leaking pipeline is calculated. The pipe diameter d is determined based on the flow area A of the leaking pipe.
[0021] The formula for calculating the flow area A of the leaking pipeline is: ; in, The amount of oil leakage in the leaking pipeline is the sum of the oil leakage amounts Q at all leak points in the pipeline. Indicates the fuel flow coefficient of the pipeline; This indicates the density of the fuel.
[0022] When designing pipeline engineering, the diameter of the pipeline must be greater than the diameter d of the pipeline.
[0023] The method for determining the pipeline strength is as follows: based on the calculated value of the oil leakage point pressure P at each of the oil leakage points, simulation calculations are performed to obtain the pipeline strength.
[0024] Step S500: Based on the location and components of each oil leak point, the calculated values of the oil leakage amount Q and the oil leak pressure P of each oil leak point, and the characteristics of the oil leak pipe, the layout of the oil leak pipe is carried out, and the laying location of the oil leak pipe is determined. The oil leaking pipeline leaks oil by gravity. Therefore, the oil leaking pipeline is laid below all the oil leak points and above the oil leak tank. The fuel from each oil leak point is collected in the oil leak tank through the oil leaking pipeline.
[0025] In addition to the drain switch, the oil leak tank should be equipped with an ejector conduit to eject the accumulated oil in the oil leak tank to the outside of the engine when in operation.
[0026] Step S600: Determine the characteristics and location of the ejector based on fluid dynamics simulation calculations; The determination of the characteristics and location of the ejector includes the following: Based on fluid dynamics simulation calculations, the characteristics of the ejector are determined, including the structure and main parameters of the ejector. The gas extraction location is determined based on the structure of the ejector; The position of the ejector is determined based on the structure of the ejector and the requirements of the engine outline.
[0027] Step S700: Obtain the engine maintenance requirements, outer contour design requirements, and the outer contour of the aircraft engine compartment. Combine the calculated values of the oil leakage amount Q and the oil leakage pressure P at each of the aforementioned oil leakage points to determine the characteristics and location of the oil leakage tank and complete the design of the aero-engine oil leakage system.
[0028] The characteristics and location of the leaking tank include the following: Based on the calculated oil leakage amount Q at each leak point and the engine maintenance requirements, the volume V of the oil leak tank is determined. For example, if the calculated oil leakage amount Q at a certain leak point is 1 ml / min, and the expected storage period in the non-oil-sealed state according to the engine maintenance and usage requirements is 30 days, the minimum volume V of the oil leak tank for storing the engine for 30 days can be calculated as V = 1 ml / min × 30 × 24 × 60. When conducting engineering design, the volume of the oil leak tank must be ≥ V.
[0029] The strength of the oil leak tank is determined based on the calculated value of the oil leak pressure P at each of the aforementioned oil leak points. The outline of the oil leak tank is determined based on the engine outer contour design requirements and the outline of the aircraft engine compartment. The location of the oil leak tank is determined based on its outer contour and the location of the oil leak pipeline.
[0030] The oil leak tank is located at the lowest point of the engine accessories, below other accessories and oil leak lines.
[0031] The design method of this invention identifies oil leak points, obtains the oil leakage volume and pressure in both working and non-working states, calculates the oil leakage volume and pressure, determines the characteristics of the oil leakage pipeline, lays out the oil leakage pipeline, and determines the laying location of the oil leakage pipeline, thereby determining the characteristics and location of the ejector and the oil leakage tank, and completing the design of the aero-engine oil leakage system. Through the design of the oil leakage pipeline, ejector, and oil leakage tank, oil leaks from various engine accessories and fuel in the fuel main are discharged from the engine through the ejector. When the engine is parked, the fuel in the oil leakage system can flow into the oil leakage tank, preventing fuel lubrication from entering the cavity and ensuring engine operating safety.
[0032] The above-disclosed embodiments are merely specific examples of the present invention. However, the present invention is not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.
Claims
1. A design method for an aircraft engine oil leakage system, characterized in that, Includes the following: The components of an aircraft engine oil leak system are identified, including a main fuel distributor, a leak tank, an ejector, and leak lines. Identify the location and components of all oil leaks in the aircraft engine; the locations of the oil leaks include engine accessories, main pipes and pipelines, and other locations; the components of the oil leaks include the fuel centrifugal booster pump, main pump-control unit, main fuel distributor, nozzle fuel source pump, and afterburner fuel pump; all oil leaks are connected to the oil tank via leak pipes. Obtain the oil leakage amount Q and oil leakage point pressure P at each oil leakage point in both working and non-working states, and determine the calculated values of the oil leakage amount Q and oil leakage point pressure P at each oil leakage point. Based on the calculated values of the oil leakage amount Q and the oil leakage pressure P at each oil leakage point, the characteristics of the oil leakage pipe are determined, including the pipe diameter d and the pipe strength. Based on the location and components of each oil leak point, the calculated values of the oil leakage amount Q and the oil leakage pressure P at each oil leak point, and the characteristics of the oil leak pipe, the layout of the oil leak pipe is carried out, and the laying location of the oil leak pipe is determined. Based on fluid dynamics simulation calculations, the characteristics and location of the ejector are determined; By obtaining the engine's maintenance requirements, external contour design requirements, and the external contour of the aircraft engine compartment, and combining the calculated values of the oil leakage amount Q and the oil leakage pressure P at each of the aforementioned oil leakage points, the characteristics and location of the oil leakage tank are determined, and the design of the aero-engine oil leakage system is completed.
2. The design method for an aircraft engine oil leakage system as described in claim 1, characterized in that, The method for determining the calculated values of the oil leakage amount Q and the oil leakage pressure P at each leakage point is as follows: The oil leakage amount Q and oil leakage point pressure P of each oil leakage point are compared in both working and non-working states. The oil leakage amount Q and oil leakage point pressure P with the larger value in the two states are used as the corresponding calculated values.
3. The design method for an aircraft engine oil leakage system as described in claim 1, characterized in that, The method for determining the pipe diameter d includes the following: Obtain the outlet pressure P0 of the ejector drain pipe, and calculate the pipeline pressure difference ΔP based on the calculated value of the oil leakage point pressure P at each of the oil leakage points. Based on the calculated oil leakage amount Q at each leak point, and combined with the pipeline pressure difference ΔP, the flow area A of the leaking pipeline is calculated. The pipe diameter d is determined based on the flow area A of the leaking pipe.
4. The design method for an aircraft engine oil leakage system as described in claim 3, characterized in that, The formula for calculating the flow area A of the leaking pipeline is: ； in, The amount of oil leakage in the leaking pipeline is the sum of the oil leakage amounts Q at all leak points in the pipeline. Indicates the fuel flow coefficient of the pipeline; This indicates the density of the fuel.
5. The design method for an aircraft engine oil leakage system as described in claim 1, characterized in that, The method for determining the pipeline strength is as follows: based on the calculated value of the oil leakage point pressure P at each of the oil leakage points, simulation calculations are performed to obtain the pipeline strength.
6. The design method for an aircraft engine oil leakage system as described in claim 1, characterized in that, The location of the oil leakage pipeline is as follows: the oil leakage pipeline is laid below all the oil leakage points and above the oil leakage tank.
7. The design method for an aircraft engine oil leakage system as described in claim 1, characterized in that, The determination of the characteristics and location of the ejector includes the following: Based on fluid dynamics simulation calculations, the characteristics of the ejector are determined, including the structure and main parameters of the ejector. The gas extraction location is determined based on the structure of the ejector; The position of the ejector is determined based on the structure of the ejector and the requirements of the engine outline.
8. The design method for an aircraft engine oil leakage system as described in claim 1, characterized in that, The characteristics and location of the leaking tank include the following: Based on the calculated oil leakage amount Q at each of the aforementioned oil leakage points and the engine maintenance requirements, the volume V of the oil leakage tank is determined. The strength of the oil leak tank is determined based on the calculated value of the oil leak pressure P at each of the aforementioned oil leak points. The outline of the oil leak tank is determined based on the engine outer contour design requirements and the outline of the aircraft engine compartment. The location of the oil leak tank is determined based on its outer contour and the location of the oil leak pipeline.
9. The design method for an aircraft engine oil leakage system as described in claim 8, characterized in that, The oil leak tank is located at the lowest point of the engine accessories, below other accessories and oil leak lines.