Radial Compressor Blade Clearance Control Using Diaphragm Assembly
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional radial compressors in gas turbine engines lack a mechanism to maintain a consistent radial clearance between impeller blade tips and the compressor shroud, leading to efficiency losses due to air leakage or blade rubbing, and existing adjustment mechanisms using gears suffer from performance issues like gear pitch diameter run-out and tooth backlash.
Innovation Solution
A diaphragm assembly that flexes within its elastic range to move the compressor shroud, eliminating the need for gears by using an actuator to apply force and create a restoring force that maintains a desired radial clearance, preventing blade rubbing while adjusting to changing operational conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the radial clearance between impeller blade tips and compressor shroud is reduced to improve compressor efficiency, then air leakage is reduced and compression ratio increases, but the blade tips may rub against the compressor shroud causing damage and efficiency loss
Solution Approach 1:
The patent applies a dynamic adjustment mechanism that allows the compressor shroud to move axially in response to changing operating conditions. The shroud position is adjusted based on detected parameters (such as temperature, pressure, or speed) to maintain optimal radial clearance throughout the operating range, preventing both excessive clearance and blade rubbing
Solution Approach 2:
The system incorporates a feedback control mechanism where operating parameters are detected and used to adjust the shroud position accordingly. The control system continuously monitors the operating state and modifies the shroud position to maintain the optimal radial clearance, ensuring compressor efficiency while preventing blade rubbing
2Adaptability or versatility
If a gear-based adjustment mechanism is used to control radial clearance, then the clearance can be adjusted, but gear pitch diameter run-out and tooth backlash cause performance issues
Solution Approach 1:
The patent replaces the traditional gear-based mechanical adjustment mechanism with an alternative actuation system. This substitution eliminates the problems of gear pitch diameter run-out and tooth backlash by using a different mechanical principle (such as a cam mechanism, screw mechanism, or direct actuator) to control the shroud position, thereby maintaining adaptability while improving reliability
Solution Approach 2:
The system changes the operational parameters of the adjustment mechanism by using detection of operating conditions (temperature, pressure, speed) to directly control the shroud position adjustment. This parameter-based control approach eliminates the need for complex gear mechanisms and their associated errors
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 diaphragm assembly effectively maintains a small radial clearance between impeller blade tips and the shroud, enhancing compressor efficiency and preventing damage, while eliminating the performance issues associated with gear-based systems.
Implementation Method 1
A diaphragm assembly that flexes within its elastic range to move the compressor shroud
Data Source
AI summary
A diaphragm assembly includes a cylinder, a circular flange, and a diaphragm. The cylinder defines an axis and includes a first end and a second end opposite the first end. The circular flange is coaxial with the cylinder and at a greater radial distance from the axis than the cylinder. The diaphragm extends from the second end of the cylinder to the flange.