Stator Blade Serration Amplitude Gradient for Stress Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing fixed blade aero-acoustic management systems in turbomachines face challenges in reducing noise emissions due to high stress concentrations in the teeth of the leading edge, which compromises mechanical balance and acoustic gain, particularly at varying engine speeds.
Innovation Solution
A stator vane with a leading edge featuring a series of teeth and hollows where the amplitude and thickness increase or decrease progressively from the blade root or tip, following a sinusoidal, linear, parabolic, or exponential function, to distribute load and reduce stress concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the teeth at the leading edge are made longer to increase acoustic gain, then noise reduction is improved, but stress concentration in the tooth hollows increases and mechanical balance deteriorates
Solution Approach 1:
The patent applies local quality by varying the amplitude of serrations along the span of the blade. The amplitude is maximum at the mid-span and decreases toward the root and tip, creating different local characteristics that optimize both acoustic performance and structural integrity in different regions. This gradient approach allows long teeth for noise reduction where needed while shorter teeth near roots/tips maintain mechanical balance.
Solution Approach 2:
The patent implements dynamics by making the serration amplitude a function of the radial position along the blade span. Rather than uniform static teeth, the amplitude varies dynamically across the blade, with the formula A(r) = A_max * (1 - (2*r/(R_root+R_tip) - 1)^2), creating an optimized distribution that adapts to the structural and acoustic requirements at different locations.
2Object-generated harmful factors
If the teeth are made thinner to maximize acoustic gain, then noise reduction is improved, but the radius of tooth grooves decreases and stress concentration increases
Solution Approach 1:
The patent applies local quality by making the tooth thickness a function of radial position. Teeth are thinner at mid-span where acoustic gain is prioritized and progressively thicker toward the root and tip where structural strength is needed. This local variation in thickness optimizes the trade-off between acoustic performance and stress resistance in different blade regions.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
Stator blade (100) comprising: - a blade foot (110), - a blade head (115), - a leading edge (120) extending between the foot (110) and the head (115), the leading edge having a serrated profile presenting a succession of teeth (122) and grooves (124) each having an amplitude and a thickness, characterized in that a series (300) of at least three teeth (122) and three grooves (124) consecutive from the blade foot (110) and/or the blade head (115) has an increasing amplitude and/or thickness.