HP Rotor Vane Incidence Control for Thrust Crossover Vibration
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Solution Overview
Problem
High-pressure rotors in turbine engines experience significant vibrations during thrust crossover and reversal conditions, leading to reduced lifecycle due to decreased axial forces and increased deflections in bearings.
Innovation Solution
A control system that adjusts the incidence angle of variable stator vanes in the high-pressure rotor to increase axial thrust, reducing vibrations by controlling the air mass flow rate through the compressor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the high-pressure rotor operates during thrust crossover and reversal conditions, then the turbine engine can maintain continuous operation, but significant vibrations occur leading to reduced lifecycle
Solution Approach 1:
The control system detects approaching thrust crossover conditions and proactively adjusts the incidence angle of variable stator vanes before vibrations become significant. By anticipating the thrust crossover event and pre-adjusting the vanes to increase axial thrust, the system prevents the harmful vibration condition rather than reacting after it occurs, thus maintaining continuous operation while protecting rotor integrity
Solution Approach 2:
The control system continuously monitors rotor thrust and vibration levels, using this feedback to dynamically adjust the incidence angle of the variable stator vanes. When thrust crossover is detected or anticipated, the system modifies vane positioning to increase axial thrust and reduce vibrations, creating a closed-loop control that balances continuous operation with rotor protection
2Adaptability or versatility
If axial forces on bearings are decreased during thrust crossover, then the rotor can experience thrust reversal, but bearing deflections increase leading to vibrations
Solution Approach 1:
The control system changes the incidence angle parameter of the variable stator vanes to alter the aerodynamic forces acting on the rotor. By adjusting this geometric parameter, the system increases axial thrust during thrust crossover conditions, which in turn increases bearing loads and reduces bearing deflections, thereby stabilizing the rotor-bearing system while still allowing thrust reversal operation
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 system effectively reduces vibrations in the high-pressure rotor, thereby extending its lifecycle and improving the overall durability of the turbine engine.
Implementation Method 1
controlling the air mass flow rate through the compressor
Implementation Method 2
increase axial forces on the one or more bearings
Data Source
AI summary
A high-pressure (HP) rotor control system includes an HP rotor and a controller. The HP rotor includes a plurality of rotor blades that rotate about a centerline axis, and a plurality of variable stator vanes (VSVs) that are rotatable about a variable stator vane (VSV) pitch axis. The plurality of VSVs are disposed at an incidence angle. The controller controls the plurality of VSVs to rotate the plurality of VSVs about the VSV pitch axis to change the rotor incidence angle of the plurality of VSVs as the HP rotor approaches a thrust crossover condition.