Compressed-Air Injector Layout for Faster Compressor Rotor Acceleration
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Solution Overview
Problem
Gas turbine engines in aircraft powerplants experience lag in response when rapidly increasing power settings due to delays in accelerating engine rotating assemblies.
Innovation Solution
An air system is integrated into the turbine engine to direct compressed air from an air source to air injectors, which project into the flowpath and apply a rotational driving force onto the compressor rotor, enhancing the acceleration of the compressor blades and vanes to reduce response time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If compressed air is directed against compressor blades to accelerate the rotor, then the response time is reduced, but the radial space available in the flowpath is limited
Solution Approach 1:
The air injector is positioned to direct compressed air at specific locations on the compressor blades (leading edges or mid-span regions) rather than uniformly across the entire blade array. This localized application of force optimizes the acceleration effect while minimizing the radial space required for the injector system.
Solution Approach 2:
The air injector projects radially into the flowpath but is positioned axially between the compressor vane array and compressor blade array, utilizing the axial dimension to accommodate the injector while maintaining sufficient radial clearance. This spatial arrangement allows the injector to deliver compressed air effectively without occupying excessive radial space.
2Productivity
If the air injector projects deeper into the flowpath, then more compressor blades can be engaged, but the risk of interfering with other engine components increases
Solution Approach 1:
The air injector is positioned axially between the compressor vane array and compressor blade array, allowing it to engage the compressor blades at an optimal location before the blades reach positions where they might interfere with other engine components. This preliminary positioning ensures effective acceleration while avoiding harmful interference.
Solution Approach 2:
The air injector acts as an intermediary component that delivers compressed air to the compressor blades through a controlled projection distance (equal to or less than three-quarters of the radial height). This intermediate positioning allows the injector to effectively engage the blades while maintaining safety margins from other engine components.
3Loss of time
If known systems and methods are used to reduce engine response time, then some improvement is achieved, but further improvement is still possible
Solution Approach 1:
The system uses compressed air (pneumatics) to directly accelerate the compressor rotor by directing high-velocity air streams against the compressor blades. This pneumatic acceleration method provides rapid response time improvement with relatively simple system architecture, avoiding complex mechanical or electronic control systems.
Solution Approach 2:
The air injector system utilizes compressed air that is already available in the engine's air circuit, eliminating the need for separate power sources or complex control mechanisms. The system leverages existing engine resources to achieve acceleration, reducing overall system complexity while improving response time.
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
The air system facilitates a more rapid power increase by boosting the rotational driving force on the compressor rotor, reducing lag and improving the engine's response time during power setting changes.
Implementation Method 1
The air injector is configured to direct a stream of the compressed air into the flowpath and against one or more of the compressor blades to apply a rotational driving force onto the compressor rotor
Implementation Method 2
apply a rotational driving force onto the compressor rotor about the axis in the direction
Data Source
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AI summary
An assembly for an aircraft powerplant (20) includes a compressor rotor (38) that includes a plurality of compressor blades arranged in a compressor blade array in a flowpath (56). An air system (26) includes an air source (68), an air injector (72) and an air circuit (70) fluidly coupling the air source (68) to the air injector (72) and is configured to direct compressed air from the air source (68) to the air injector (72) through the air circuit (70). The air injector (72) is configured to direct a stream of the compressed air into the flowpath (56) and against one or more of the compressor blades to apply a rotational driving force onto the compressor rotor (38) about an axis (32). The air injector (72) projects a radial distance into the flowpath (56) at the injector location.