Plasma-Actuated Fluidic Control for Turbine Clearance
Solution Overview
Problem
Existing methods for controlling blade tip clearance in gas turbine engines are unable to respond quickly to changes during transient maneuvers and are often bulky or complex, with mechanical actuation components facing high wear and cost issues due to frequent movements.
Innovation Solution
A fluidic actuator comprising a fluid nozzle, a tube with electrodes to create a spark gap and generate plasma, reducing the effective length of the tube to control fluid flow and block leakage air, with no moving mechanical parts and adjustable voltage sources for efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If mechanical actuation methods are used to control blade tip clearance, then the clearance can be adjusted, but the response speed is too slow for transient maneuvers and mechanical components wear out quickly due to frequent movements
Solution Approach 1:
The patent replaces mechanical actuation systems with a fluidic actuator that uses plasma-generated pressure waves to control fluid flow and blade tip clearance. This eliminates moving mechanical parts that wear out, while achieving rapid response to transient maneuvers through electrical plasma generation.
Solution Approach 2:
The patent changes the physical state of gas within the tube by creating plasma through electrical discharge. This parameter change (from neutral gas to plasma) generates pressure waves that control fluid flow without mechanical movement, resolving the contradiction between response speed and component reliability.
2Ease of operation
If mechanical actuation components are used to control clearance, then clearance adjustment is achieved, but the device becomes bulky and complex with many moving parts
Solution Approach 1:
The patent substitutes complex mechanical actuation systems with a simplified fluidic actuator using plasma and pressure waves. This reduces device complexity while maintaining clearance control functionality, and eliminates the need for bulky mechanical components with many moving parts.
Solution Approach 2:
The patent uses pneumatic principles by generating pressure waves through plasma discharge in a gas-filled tube. These pressure waves control fluid flow and clearance without mechanical contact, simplifying the system while maintaining operational effectiveness.
3Temperature
If cool air is supplied to the casing to reduce radial dimension, then clearance is controlled during cruise phase, but the method cannot respond quickly to transient maneuvers
Solution Approach 1:
The patent changes the physical state of gas within the tube by creating plasma through electrical discharge. This parameter change (from neutral gas to plasma) generates pressure waves that control fluid flow without mechanical movement, resolving the contradiction between response speed and component reliability.
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
Enables rapid and efficient control of blade tip clearance with reduced wear and cost, improving engine efficiency by blocking leakage air and directing it to do useful work, while avoiding blade tip rub and vibration.
Implementation Method 1
a voltage source arranged to supply a voltage across the pair of electrodes wherein the voltage causes plasma formation in the spark gap thereby shortening the effective length of the tube
Implementation Method 2
a fluid nozzle for delivering fluid; a tube having an open end and a closed end, the open end spaced from the fluid nozzle
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A fluidic actuator (64) comprising: a fluid nozzle (52) for delivering fluid and a tube (56) having an open end (58) and a closed end (60), the open end (58) spaced from the fluid nozzle (52). Also a pair of electrodes (66) mounted in the tube (56) and spaced apart to create a spark gap therebetween. A voltage source (68) is arranged to supply a voltage across the pair of electrodes (66) wherein the voltage causes plasma formation in the spark gap thereby shortening the effective length (x) of the tube (56).