Coanda Fluidic Tip Clearance Control for Gas Turbines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional active tip clearance control systems in gas turbine engines are complex, often include moving parts, and can incur higher pressure losses, making them less reliable and more cumbersome compared to the proposed solution.
Innovation Solution
An active tip clearance control system utilizing a Coanda effect fluidic device to selectively direct clearance control fluid either towards the turbine section or a bypass duct, incorporating a nozzle with control ports and valves to manage the flow, thereby reducing mechanical complexity and pressure losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional active tip clearance control systems are used, then tip clearance control is achieved, but system complexity increases and reliability decreases due to moving parts
Solution Approach 1:
The patent replaces conventional mechanical valves and moving parts with a fluidic device that uses fluid dynamics (Coanda effect) to control cooling air flow. This substitution eliminates mechanical complexity and moving parts, thereby improving reliability while maintaining tip clearance control functionality.
Solution Approach 2:
The invention uses pneumatic principles by directing cooling air flow through fluidic passages and utilizing the Coanda effect to control the flow direction. This pneumatic control mechanism replaces mechanical actuation, reducing device complexity and improving system reliability.
2Loss of energy
If conventional active tip clearance control systems with valves are used, then flow control is achieved, but pressure losses increase
Solution Approach 1:
By replacing mechanical valves with a fluidic device, the system eliminates the pressure losses associated with mechanical valve restrictions and moving parts. The fluidic design maintains flow control capability while reducing energy losses through optimized fluid pathways.
Solution Approach 2:
The fluidic device changes the flow parameters (direction and distribution) of cooling air through controlled fluid dynamics rather than mechanical restriction. This allows effective flow control with minimized pressure losses by utilizing fluid attachment and detachment phenomena.
3Measurement precision
If complex feedback control means are used, then precise tip clearance control is achieved, but device complexity and mechanical requirements increase
Solution Approach 1:
The fluidic device utilizes self-regulating fluid dynamics characteristics, where the cooling air flow automatically adjusts its path based on pressure differentials and flow conditions. This self-service mechanism provides precise control without requiring complex external feedback systems or additional mechanical components.
Solution Approach 2:
The system employs pneumatic feedback through pressure differential sensing inherent in the fluidic structure itself, eliminating the need for separate mechanical sensors and actuators. This integrated pneumatic control achieves precise tip clearance control with minimal added complexity.
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 achieves efficient and reliable active tip clearance control with reduced mechanical complexity and pressure losses, enhancing the operational efficiency and safety of gas turbine engines.
Implementation Method 1
a Coanda effect fluidic device configured to control a flow of clearance control fluid delivered via the transfer conduit to the tip clearance control apparatus
Data Source
AI summary
An active tip clearance control system of a gas turbine engine and an associated method are disclosed. The system comprises a Coanda effect fluidic device configured to control a flow of clearance control fluid to a turbine section of the gas turbine engine for active tip clearance control.