Turbine Rotor Blade Camber Optimization for Flutter Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbine rotor blades in axial flow machines tend to flutter due to self-induced vibrations, leading to material fatigue and the need for costly replacements, and conventional solutions either reduce efficiency or require complex damping elements.
Innovation Solution
A method for profiling turbine rotor blades by adjusting the mean camber line to maximize the difference in isentropic Mach number between the pressure and suction sides, using a combination of fourth-degree polynomials to define the camber line, which reduces the tendency for flutter and eliminates the need for additional damping elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the blade aspect ratio is increased and the blade is made thinner to improve efficiency, then the blade efficiency is improved, but the blade tends to flutter during operation
Solution Approach 1:
The invention changes the geometric parameters of the blade profile by optimizing the mean camber line configuration. Specifically, the camber line is designed to maximize the difference in isentropic Mach number between the pressure and suction sides in the rear 65% of the blade chord, which fundamentally alters the pressure distribution characteristics and reduces flutter tendency while maintaining high aspect ratio and thin blade design for efficiency.
2Reliability
If damping elements such as a shroud are added to prevent flutter, then the blade stability is improved, but the device complexity increases
Solution Approach 1:
The invention extracts and eliminates the need for additional damping elements like shrouds by incorporating flutter-reducing characteristics directly into the blade profile design. The optimized mean camber line configuration inherently suppresses flutter through favorable pressure distribution, thereby removing the requirement for complex external damping structures.
3Reliability
If the load acting on the blade is reduced to prevent flutter, then the blade stability is improved, but the axial flow machine efficiency is reduced
Solution Approach 1:
The invention changes the aerodynamic parameters of the blade by optimizing the mean camber line to create a pressure distribution that reduces flutter tendency. This allows the blade to withstand higher loads without fluttering, thereby maintaining high axial flow machine efficiency while improving blade stability and preventing material fatigue.
Data Source
AI summary
A method for profiling a turbine rotor blade for an axial flow machine, having the following steps: providing a geometric model of a blade profile, having a camber line of a profile section of the turbine rotor blade; determining boundary conditions for a flow flowing around the turbine rotor blade; changing the camber line such that the flow which is adjusted by the boundary conditions produces the maximum of the difference of the isentropic mach number between the pressure side and the suction side of the turbine rotor blade in a blade section which extends from the blade trailing edge in the direction towards the blade leading edge and the length of which is 65% of the length S of the blade chord.