A method for optimizing the spatial position of an aircraft engine oil suction port

Abstract

The application belongs to the technical field of aircraft engine oil supply and aircraft tank liquid sloshing, and particularly relates to a spatial position optimization layout method of an aircraft engine oil suction port, steps S1: obtaining the maximum mass of fuel consumed by the engine per unit time, determining the cross-sectional area characteristic parameter of the engine oil suction port, determining the minimum distance between the oil suction port and the nearby structure wall plate, and obtaining a first feasible domain in which the oil suction port and the nearby structure wall plate maintain a minimum distance or above; step S2: obtaining multiple working conditions that affect the fuel movement of the tank, obtaining the limit position of the oil surface trajectory under each working condition through simulation, and obtaining the common part of the limit positions of the oil surface trajectory under all working conditions as a second feasible domain; step S3: obtaining the common part of the first feasible domain and the second feasible domain as the final selection area of the best position of the engine oil suction port, and when the first feasible domain and the second feasible domain have no common part, modifying the tank parameters and returning to step 1.

Description

Technical Field

[0001] This application belongs to the fields of aircraft engine fuel supply technology and aircraft tank liquid sloshing technology, and specifically relates to a method for optimizing the spatial location of the aircraft engine fuel inlet. Background Technology

[0002] During takeoff, landing, and cruise, aircraft are subject to gusts, turbulence, or the release of weapons, which can cause the fuel in the fuel tank to slosh. During maneuvering flight, the movement of the fuel in the fuel tank is even more intense, and the direction of gravity experiences alternating cycles of positive overload, zero overload, and negative overload. Under the influence of inertial forces, the fuel in the fuel tank may detach from the fuel pump inlet or float in a discontinuous form, causing the fuel pump to draw in air and lose its ability to perform continuous work. As a result, the engine cannot obtain a continuous supply of fuel, which may lead to engine failure in the air.

[0003] To prevent in-flight engine failures, the spatial location of the engine fuel intake must be precisely designed. In the past, theoretical analysis and experimental simulation methods were commonly used to assist in optimization. Theoretical research is based on the conservation of mass, momentum, and energy to form corresponding mathematical descriptions. It is difficult to establish a reasonable theoretical model for engineering problems, and analytical solutions are even more difficult. Therefore, many assumptions are proposed that deviate from engineering reality. While experimental simulations provide reliable results and can be used to study complex problems, they are limited by physical dimensions, environmental interference, operational safety, and measurement accuracy. They are difficult to implement, require significant funding, manpower, and material resources, and have long testing cycles. There is an urgent need to develop a more efficient and convenient method for designing the spatial location of aircraft engine fuel intakes, covering continuous fuel supply under complex flight environment factors, to guide the design of aircraft fuel supply systems. Summary of the Invention

[0004] To address the aforementioned problems, this application provides a method for optimizing the spatial location of an aircraft engine oil intake port, comprising:

[0005] Step S1: Obtain the maximum mass of fuel consumed by the engine per unit time, determine the cross-sectional area characteristic parameters of the engine oil intake port, determine the minimum distance between the oil intake port and the nearby structural wall panel, and obtain the first feasible region where the oil intake port and the nearby structural wall panel maintain a minimum distance or above.

[0006] Step S2: Obtain multiple operating conditions that affect the movement of fuel in the fuel tank, obtain the extreme position of the fuel surface trajectory under each operating condition through simulation, and find the common part of the extreme positions of the fuel surface trajectory under all operating conditions as the second feasible region.

[0007] Step S3: Obtain the common part of the first feasible region and the second feasible region as the final selection area for the optimal position of the engine oil inlet. If the first feasible region and the second feasible region have no common part, modify the oil tank parameters and return to step 1.

[0008] Preferably, the larger of the fuel consumption performance parameters of the engine body and the maximum fuel consumption rate within the flight envelope of the new aircraft is taken as the maximum mass of fuel consumed by the engine per unit time.

[0009] Preferably, the method for calculating the minimum distance between the oil suction port and the nearby structural wall panel includes:

[0010] Based on the maximum mass of fuel consumed by the engine per hour, m max (kg) and the fuel density ρ (kg / m³) at that time 3 (), at the maximum safe flow rate v of fuel in the fuel supply line. max With (m / s) as the upper limit, the minimum cross-sectional area s of the engine oil suction port is determined according to the following formula. in (m 2 ):

[0011]

[0012] Based on the minimum cross-sectional area s of the engine oil intake port in (m 2 Determine the perimeter l (m) of the engine's oil intake cross-section, and then determine the minimum distance h (m) between the oil intake and the surrounding structural wall panels using the following formula:

[0013]

[0014] Preferably, the method for calculating the extreme position of the oil surface trajectory specifically includes:

[0015] Step S21: Obtain all possible state transition conditions that the engine may experience during normal operation within the flight envelope of the new aircraft, extract the overload value, remaining fuel quantity and total volume ratio of the corresponding time when the condition appears in the flight profile, and form a design analysis condition set based on the fuel tank geometry and fuel physical property parameters.

[0016] Step S22: By classifying, merging and filtering the design analysis working condition set shown, and following the merging principle of large overload envelope small overload, rapid change covering slow change, and small excess oil quantity being more stringent than large excess oil quantity, the working condition with the most severe fuel sloshing is initially identified, and a simulation analysis state set is formed.

[0017] Step S23: Using Fluent or StarCCM fluid simulation tools, establish a geometric model that reflects the internal volume details of the aircraft fuel tank, complete the mesh generation, transform the external constraints that reflect the simulation analysis state into boundary conditions, calculate and save the extreme position of the oil surface trajectory under the simulation analysis state.

[0018] Obtain the extreme positions of the oil surface trajectory under all simulation analysis states, and find the common part of the extreme positions of all oil surface trajectories as the extreme positions of the oil surface trajectory that satisfy all operating conditions within the flight envelope of the new aircraft.

[0019] The advantages of this application include: 1) Quickly obtaining the optimal position of the engine oil intake port, which reflects engineering details.

[0020] This technology incorporates analytical geometry and computational fluid dynamics simulation methods. It relies on the fundamental theories and physical laws of analytical geometry, mass conservation, energy conservation, and momentum conservation, and has been widely applied in complex engineering problems. The use of CFD simulation software platforms has been widely recognized in the industry. By strictly standardizing modeling criteria, the quality of model reproduction of engineering details is improved. It can obtain the morphology of the oil-gas separation interface inside the fuel tank during flight in a short time, quickly support the design of new aircraft fuel supply systems, and effectively show the optimal spatial area of ​​the engine fuel intake.

[0021] 2) Efficiently solve multi-constrained strongly nonlinear space optimization problems

[0022] Optimizing the space of an aircraft engine fuel inlet falls under the category of liquid sloshing problems in aircraft tanks. Liquid sloshing is a widespread phenomenon in aerospace, shipbuilding, petrochemical, and nuclear power industries. It is a common phenomenon where the free surface of a liquid moves due to external disturbances or excitations. It is also a complex coupled phenomenon involving the interaction between liquids and solids, influenced by multiple independent factors such as external loads, tank shape, fuel properties, and gas-liquid ratio. It exhibits strong nonlinear characteristics and is a recognized technical challenge in aircraft design. This technique introduces computer fluid dynamics simulation methods, decomposing multiple constraints into various combinations of states. Numerical solutions replace analytical solutions to decouple the strongly nonlinear relationships, thereby improving the efficiency of solving spatial optimization problems.

[0023] 3) Fully covers all motion states anticipated during the aircraft design phase.

[0024] During the conceptual design phase of a new aircraft's operation and use, simulations of aircraft usage scenarios and operating environments are conducted to obtain the expected states the aircraft will experience throughout its entire lifecycle. This requires the engine fuel supply system to operate reliably under all anticipated motion scenarios. For sudden external factors such as gusts, atmospheric turbulence, and disturbances, it is difficult to simulate them using experimental methods. However, this method allows for flexible changes to input parameters, realistic simulation of continuous flight processes, comprehensive coverage of all anticipated scenarios, and the development of reasonable design analysis schemes. It can seamlessly address the overall aircraft operation's demands on engine fuel supply and possesses the ability to globally optimize the spatial position of the engine fuel intake.

[0025] 4) Significantly reduces R&D costs and shortens the design cycle.

[0026] Before the widespread application of this method, the selection of the spatial location of the aircraft engine fuel intake could only be assisted by two technical approaches: mathematical analysis and physical experiments. The former has a narrow scope of application, and in order to reduce the order and number of expressions, it is necessary to introduce assumptions to significantly simplify engineering details, resulting in uncontrollable errors in the analysis results. In the aircraft design process, physical experiments often play a verification role. When used to guide design optimization, there are inevitably a large number of design and verification iterations, which require a lot of time and material resources. In addition, the construction of the physical testing environment itself also requires a large investment of human, financial, and material resources, leading to increased aircraft development costs and extended cycles. This method replaces the role of physical experiments in the design phase. It can quickly complete multiple rounds of scheme iteration in a virtual environment in the form of performance models and geometric models to obtain the optimal spatial location of the engine fuel intake. This not only improves the optimization accuracy but also reduces costs and cycle time, supporting efficient aircraft development activities. Attached Figure Description

[0027] Figure 1 This is a flowchart of a preferred embodiment of the method for optimizing the spatial location of an aircraft engine oil intake port according to this application. Detailed Implementation

[0028] To make the technical solution and advantages of this application clearer, the technical solution of this application will be described in a clearer and more complete manner below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of this application, and are only used to explain this application, not to limit this application. It should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings. Other related parts can be referred to the general design. In the absence of conflict, the embodiments and technical features in the embodiments of this application can be combined with each other to obtain new embodiments.

[0029] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., used in this application description to indicate relative direction or positional relationship are used only to indicate relative orientation or positional relationship, and do not imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. When the absolute position of the described object changes, its relative positional relationship may also change accordingly, and therefore should not be construed as a limitation on this application. The terms "first," "second," "third," and similar terms used in this application description are used only for descriptive purposes to distinguish different components, and should not be construed as indicating or implying relative importance. The terms "a," "one," or "the," etc., used in this application description should not be construed as an absolute limitation on quantity, but should be construed as indicating the existence of at least one. The terms "including," "comprising," etc., used in this application description mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0030] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, terms such as “installation,” “connection,” and “linkage” used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can be a connection within two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0031] In the early stages of the development of a new aircraft, this application, based on the geometric model of the aircraft fuel tank, determines the cross-sectional characteristic parameters of the engine fuel inlet according to the maximum fuel consumption capacity of the engine per unit time. In order to prevent the structure around the inlet from becoming the main factor restricting fuel flow, the minimum distance between the fuel inlet and the nearby structural wall is determined by calculation.

[0032] Using computer flow dynamics simulation, the movement of fuel in the fuel tank is simulated when the aircraft is subjected to external loads. The spatial distribution characteristics of the fuel in the fuel tank are extracted. By covering all the expected motion states of the aircraft, computer-aided design software is used to reproduce all fuel distribution patterns and geometric constraints such as the distance and cross-sectional area of ​​the intake ports. The common spatial area is used as the quantitative basis for the design of the engine fuel intake ports of the aircraft. When there is a lack of common intersection areas, it is necessary to increase the number of fuel intake ports or modify the design input parameters to guide the iterative optimization and maturation of the physical location of the aircraft fuel supply ports, so as to form a final design scheme that meets the requirements of aircraft use.

[0033] Specifically, this includes: such as Figure 1 As shown, Step 1: Obtain the design boundary constraints. These are derived from the design requirements for the continuous engine power output under the new aircraft's safe operation scenario, and include two sub-steps:

[0034] Sub-step 1.1: Obtain the maximum mass of fuel consumed by the engine per unit time, which is determined by the fuel consumption performance parameters of the engine itself and the maximum fuel consumption rate within the flight envelope of the new aircraft, and take the larger of the two values;

[0035] Sub-step 1.2: Obtain all possible state transition conditions that the engine may experience during normal operation within the flight envelope of the new aircraft, extract the overload value, remaining fuel quantity and total volume ratio of the fuel tank at the moment when the condition appears in the flight profile, and combine them with parameters such as fuel tank geometry and fuel physical properties to form a set of design analysis conditions;

[0036] Step 2: Establish the geometric constraints for the engine fuel intake. The input to this activity is the maximum mass of fuel consumed by the engine per unit time, obtained from sub-step 1.1. The output parameters are the minimum cross-sectional area of ​​the engine fuel intake and the minimum distance to the surrounding structure. This includes two sub-steps:

[0037] Sub-step 2.1: Based on the maximum mass m of fuel consumed by the engine per hour max (kg) and the fuel density ρ (kg / m³) at that time 3 (), at the maximum safe flow rate v of fuel in the fuel supply line. max With (m / s) as the upper limit, the minimum cross-sectional area s of the engine oil suction port is determined according to the following formula. in (m 2 ):

[0038]

[0039] Sub-step 2.2: Based on the minimum cross-sectional area s of the engine oil intake port in (m 2 Determine the perimeter l (m) of the cross section, and then determine the minimum distance h (m) between the oil suction port and the surrounding structure using the following formula:

[0040]

[0041] Step 3: Establish spatial constraints for the engine fuel intake. The input to this activity is the design analysis case set obtained in sub-step 1.2, and the output is the extreme positions of the fuel sloshing trajectory under all possible conditions experienced by the new aircraft engine during normal operation. This includes two sub-steps:

[0042] Sub-step 3.1: Form a fuel sloshing simulation state set. By classifying, merging and filtering the design analysis working condition set output from sub-step 1.2, and following the merging principle of large overload enveloping small overload, rapid change covering slow change, and small remaining fuel quantity being more stringent than large remaining fuel quantity, the most intense fuel sloshing situation is initially identified, and a simulation analysis state set is formed.

[0043] Sub-step 3.2: Obtain the extreme position of the fuel sloshing oil surface trajectory under each simulation state. Use fluid simulation tools such as Fluent or StarCCM to establish a geometric model that reflects the internal volume details of the aircraft fuel tank, complete the mesh generation, transform the external constraints that reflect the analysis state into boundary conditions, calculate and save the extreme position of the oil surface trajectory under this condition.

[0044] Sub-step 3.3: Obtain the extreme positions of the oil surface trajectory under all simulation analysis states. For each simulation state in the analysis set output by sub-step 3.1, execute sub-step 3.2 to obtain the extreme positions of the oil surface under that state. Combine the simulation results of all states and find their common part as the extreme positions of the oil surface trajectory that satisfy all flight conditions.

[0045] Step 4: Establish the feasible domain for a continuous fuel supply design. Sub-step 2.2 determines the minimum distance between the fuel inlet and the surrounding structure, and sub-step 3.3 determines the extreme positions of the oil level trajectory under all operating conditions. The common space enclosed by these two steps constitutes the feasible domain for arranging the engine fuel inlet. In practice, two scenarios may arise, which are broken down into two sub-steps:

[0046] Sub-step 4.1: If there is a common spatial intersection, it means that a design scheme that meets the continuous oil supply demand can be formed under the given constraints. Directly output the common area as the input for the next step.

[0047] Sub-step 4.2: If there is no common spatial intersection, it means that the design constraints are unreasonable and a design scheme that meets the continuous oil supply demand cannot be formed. A requirement to modify the design constraints should be proposed, and then steps 1 to 4 should be executed again until a design scheme that meets the demand can be formed.

[0048] Step 5: Determine the optimal location for the engine oil intake. Within the space available for the engine oil intake as output in Step 4, the designer selects the optimal oil intake spatial arrangement scheme based on experience and key considerations such as process, maintenance, and reliability. This scheme satisfies the continuous fuel supply requirements of the engine while also taking into account other auxiliary factors.

[0049] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for optimizing the spatial location of an aircraft engine oil intake port, characterized in that, include: Step S1: Obtain the maximum mass of fuel consumed by the engine per unit time, determine the cross-sectional area characteristic parameters of the engine oil intake port, determine the minimum distance between the oil intake port and the nearby structural wall panel, and obtain the first feasible region where the oil intake port and the nearby structural wall panel maintain a minimum distance or above. Step S2: Obtain multiple operating conditions that affect the movement of fuel in the fuel tank, obtain the extreme position of the fuel surface trajectory under each operating condition through simulation, and find the common part of the extreme positions of the fuel surface trajectory under all operating conditions as the second feasible region. Step S3: Obtain the common part of the first feasible region and the second feasible region as the final selection area for the optimal position of the engine oil inlet. If the first feasible region and the second feasible region have no common part, modify the oil tank parameters and return to step 1. The specific methods for calculating the extreme positions of the oil surface trajectory include: Step S21: Obtain all possible state transition conditions that the engine may experience during normal operation within the flight envelope of the new aircraft, extract the overload value, remaining fuel quantity and total volume ratio of the corresponding time when the condition appears in the flight profile, and form a design analysis condition set based on the fuel tank geometry and fuel physical property parameters. Step S22: By classifying, merging and filtering the design analysis working condition set shown, and following the merging principle of large overload envelope small overload, rapid change covering slow change, and small excess oil quantity being more stringent than large excess oil quantity, the working condition with the most severe fuel sloshing is initially identified, and a simulation analysis state set is formed. Step S23: Using Fluent or StarCCM fluid simulation tools, establish a geometric model that reflects the internal volume details of the aircraft fuel tank, complete the mesh generation, transform the external constraints that reflect the simulation analysis state into boundary conditions, calculate and save the extreme position of the oil surface trajectory under the simulation analysis state. Obtain the extreme positions of the oil surface trajectory under all simulation analysis states, and find the common part of the extreme positions of all oil surface trajectories as the extreme positions of the oil surface trajectory that satisfy all operating conditions within the flight envelope of the new aircraft.

2. The method for optimizing the spatial location of the aircraft engine oil intake port as described in claim 1, characterized in that, The larger of the engine's fuel consumption performance parameters and the maximum fuel consumption rate within the new aircraft's flight envelope is taken as the maximum mass of fuel consumed by the engine per unit time.

3. The method for optimizing the spatial location of the aircraft engine oil intake port as described in claim 1, characterized in that, The calculation method for the minimum distance between the oil suction port and the nearby structural wall panel is as follows: Based on the maximum mass of fuel consumed by the engine per hour and the fuel density at that time At the maximum safe speed of fuel flow in the fuel supply line As the upper limit, the minimum cross-sectional area of ​​the engine oil intake port is determined according to the following formula. : Based on the minimum cross-sectional area of ​​the engine oil intake port Determine the perimeter of the engine's oil intake cross-section. Determine the minimum distance between the oil suction port and the surrounding structural wall panels using the following formula. : 。

Images