Turbine Engine Stator Fin Geometry for Corner Separation Control
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Solution Overview
Problem
The zone of the blade root in turbine engine stator parts is prone to secondary aerodynamic flows, leading to corner separation, corner vortices, pressure losses, and aerodynamic blockage, particularly at high angles of attack, which affects the efficiency of the flow guidance.
Innovation Solution
A stator part design featuring a platform with radially extending blades and fins, where the fins have specific geometric characteristics such as angles, heights, and profiles to guide the flow without separation, reducing corner separation and aerodynamic blockage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional blade geometry is used, then the structure is simple, but corner separation and aerodynamic blockage occur at high angles of attack
Solution Approach 1:
The blade is segmented into multiple functional zones: a root zone with a fin structure to control secondary flows and corner separation, and a main blade zone for primary flow guidance. This segmentation allows each zone to be optimized independently for its specific function.
Solution Approach 2:
The fin root profile is designed with specific local geometric characteristics (angle ≤ 45 degrees between root profile and tangent to section) to control flow attachment at the critical root region, while the rest of the blade maintains its overall aerodynamic shape for flow guidance.
2Reliability
If blade geometry is optimized for high angles of attack, then flow guidance efficiency improves, but manufacturing complexity increases
Solution Approach 1:
The fin root profile is defined by controllable geometric parameters (maximum thickness, chord length, and the critical angle constraint). By adjusting these parameters, the blade can be optimized for different operating conditions while maintaining manufacturability through standardized profiling methods.
3Reliability
If fins extend further radially, then corner separation is reduced, but aerodynamic blockage increases
Solution Approach 1:
The fin extends radially to a limited height (0.01 ≤ fin height/stream height ≤ 0.25) - enough to control corner separation and guide secondary flows, but not so much as to create significant aerodynamic blockage. This partial action achieves the necessary flow control with minimal adverse effects.
Solution Approach 2:
The fin profile varies along its span, with the root section having maximum thickness and chord to control corner separation, while the tip section tapers to reduce blockage. This local variation in geometry optimizes both flow control and minimizes harmful blockage effects.
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 design effectively guides the flow, reducing separation and blockage, enhancing efficiency even at high angles of attack by minimizing transverse pressure gradients and guiding gases smoothly to the trailing edge.
Implementation Method 1
the zone of the blade root can be the site of secondary aerodynamic flows... a corner separation and a corner vortex can occur. This separation generates pressure loses as well as an aerodynamic blockage
Data Source
AI summary
The invention relates to a stator part (20) of a turbine engine, comprising a platform (22), a blade (24, 26) extending radially relative to a central axis (A), and a fin (28) extending radially from a fin root (44) to a fin tip (46), the fin comprising a lower side (48) and an upper side (50), each point (100) of the lower side or of the upper side defining a radial axis (Ar) passing through the point, each plane (Pr) that includes the radial axis defining a section (S) of the lower side or of the upper side, an angle defined in the plane between the root profile and a tangent to the section at an intersection (104) of the section and of the root profile being less than or equal to 45 degrees, the section being located between the root profile and the tangent.