Variable Blower Tip Clearance Control for Gas Turbine Engines
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Solution Overview
Problem
Existing gas turbine engines face inefficiencies and instability due to varying tip clearance between turbine blades and the engine case, which is difficult to manage with current methods, leading to undesirable contact or leakage.
Innovation Solution
A system comprising a distribution manifold and a variable blower that adjusts the flow rate of thermal fluid applied to the engine case, controlling tip clearance without the use of physical valves, by varying the rotational speed of blower blades or impellers to maintain optimal gap sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If tip clearance is reduced to prevent leakage, then operational efficiency is improved, but risk of undesirable contact between turbine blade tips and casing increases
Solution Approach 1:
The patent applies thermal expansion dynamics by heating the engine case to dynamically adjust the clearance between turbine blade tips and the casing. The thermal expansion of the case material in response to heated air flow creates a dynamic clearance control mechanism that adapts to operating conditions, preventing both excessive leakage and harmful contact.
2Reliability
If tip clearance is increased to prevent blade-casing contact, then reliability is improved, but leakage past turbine blade tips increases causing operational inefficiency
Solution Approach 1:
The patent directly applies thermal expansion by introducing heated air to the engine case, causing the case material to expand thermally. This expansion reduces the clearance between the turbine blade tips and the casing in a controlled manner, preventing leakage while avoiding harmful contact through precise thermal management.
3Measurement precision
If physical valves are used to control thermal fluid flow rate, then flow rate control precision is improved, but device complexity increases
Solution Approach 1:
The patent replaces the mechanical valve system with a direct thermal fluid injection system. Instead of using mechanical components to regulate flow, the system controls thermal fluid flow rate through injection pressure and/or flow rate mechanisms, eliminating complex mechanical valve assemblies while maintaining precise control capability.
4Manufacturing precision
If thermal fluid flow rate is increased to maintain tip clearance, then tip clearance control is improved, but energy consumption increases
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting thermal fluid flow rate based on operating conditions. The system monitors engine parameters and modifies the thermal fluid injection rate accordingly, maintaining optimal tip clearance while adapting energy consumption to actual operational needs rather than using constant high flow rates.
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 effectively manages tip clearance by adjusting thermal fluid flow rates in response to changing engine conditions, maintaining operational efficiency and preventing undesirable contact or leakage, thus enhancing the reliability and performance of gas turbine engines.
Implementation Method 1
a variable blower configured to force the thermal fluid into the distribution manifold at a flow rate adjusted by the variable blower
Implementation Method 2
The heat produced by a gas turbine engine may vary a tip clearance of rotating hardware within the gas turbine engine
Data Source
AI summary
Systems and methods for controlling tip clearance in a gas turbine engine are provided. The system may include a distribution manifold positioned along the engine case for a turbine of a gas turbine engine. The distribution manifold may include a passageway for a thermal fluid, an inlet configured to direct the thermal fluid into the passageway, an inner surface extending along and facing the outer surface of the engine case, and a plurality of outlets configured to direct the thermal fluid onto the outer surface of the engine case. The thermal fluid may include bypass air. A component may add kinetic energy to the thermal fluid.