Jet Engine Fuel Injector Penetration Height Control
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Solution Overview
Problem
Jet engines face challenges in maintaining stable flame stabilization at lower speeds due to fuel reaching regions where flame stabilization is difficult, particularly due to variations in momentum flux and penetration height of fuel, which can lead to operational instability.
Innovation Solution
A jet engine design with a fuel control section that adjusts the flow-path cross-section area of the fuel injector to control the penetration height of fuel, ensuring it passes through a flame stabilization possible region, even at varying flight speeds by modifying the number and arrangement of fuel injection ports and valves in response to flight speed commands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fuel injection system supplies fuel at constant flow rate, then the total fuel supply meets the autopilot command, but the penetration height varies with flight speed causing unstable flame stabilization
Solution Approach 1:
The patent applies dynamics by making the fuel injection system adaptive to flight speed changes. The control section dynamically adjusts the flow-path cross-sectional area of individual fuel injectors based on detected flight speed, transforming a static injection system into a dynamic one that maintains optimal penetration height across varying speeds while meeting total fuel supply requirements
Solution Approach 2:
The patent changes physical parameters by adjusting the flow-path cross-sectional area of fuel injectors in response to flight speed variations. This parameter adjustment controls the penetration height of fuel injection, ensuring it remains within the flame stabilization possible region across different operating conditions while maintaining the total fuel flow rate according to autopilot commands
2Reliability
If the fuel penetration height is increased to reach the flame stabilization region, then flame stabilization is achieved, but fuel may reach regions where stabilization is difficult at higher speeds
Solution Approach 1:
The patent applies local quality by providing different flow-path cross-sectional areas to individual fuel injectors based on their specific positions and local flow conditions. Each injector is customized with an appropriate cross-sectional area that ensures its fuel jet reaches the flame stabilization possible region without excessive penetration, accounting for local variations in air flow and combustion conditions
Solution Approach 2:
The patent changes the flow-path cross-sectional area parameter of each fuel injector to control penetration height. By adjusting this parameter individually for each injector based on flight speed and position, the system ensures fuel reaches the flame stabilization region while preventing excessive penetration into difficult-to-stabilize regions
3Manufacturing precision
If multiple fuel injectors are used to control penetration height individually, then precise fuel distribution is achieved, but the device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the fuel injection system into multiple independent injectors, each with its own controllable flow-path cross-sectional area. This segmentation allows precise local control of fuel penetration height for each injector while maintaining overall system manageability through modular design and individual control of injection ports
Solution Approach 2:
The patent applies universality by using a standardized control approach across multiple fuel injectors. The control section uses the same basic methodology (adjusting flow-path cross-sectional area based on flight speed) for all injectors, making the system scalable and manageable while achieving precise fuel distribution through consistent application of the control principle
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution allows for stable operation across a wide range of speeds, preventing fuel from entering difficult-to-stabilize regions and ensuring continuous flame stabilization, thereby enhancing the engine's operational range and efficiency.
Implementation Method 1
The fuel control section controls the flow-path cross-section area adjusting section to change the cross-section area of the pipe, such that a penetration height of the fuel is controlled
Implementation Method 2
a part of the fuel G is supplied and diffused toward a low-speed region which exists in the boundary layer developed on the wall surface 121 of the combustor 112
Implementation Method 3
a low-speed region which exists in the boundary layer developed on the wall surface 121 of the combustor 112
Data Source
AI summary
A jet engine has an inlet which takes in air, a combustor which combusts fuel by using the air, and a fuel control section which controls supply of the fuel. The combustor has a fuel supplying section which supplies the fuel, injectors which inject the fuel. Each injector contains openings which inject the fuel. The fuel supplying section supplies the fuel to the injector in a flow rate according to a command of an autopilot. The fuel control section controls the injectors such that the number of the openings which inject the fuel or flow-path cross-section areas of the pipes which send the fuel in case of the low-speed is more than the number of the openings which inject the fuel or the flow-path cross-section areas of the pipes which send the fuel in case of the high-speed.