Tandem Stator Assembly for Transonic Compressor Flow Deflection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Transonic compressors face challenges in maintaining efficient airflow straightening and flow deflection across varying operating points due to high aerodynamic loads and incidence angles, particularly in the last compression stage, which can lead to airflow separation and reduced compressor efficiency.
Innovation Solution
A turbomachine stator assembly with a tandem configuration of two successive rows of stator blades, optimized through geometric parameters such as angular pitch, circumferential spacing, and blade angles, to achieve wide-range flow deflection and incidence tolerance, enhancing aerodynamic performance and resistance to load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the number of compression stages is reduced to reduce size and weight, then the turbomachine becomes more compact, but the rotor must rotate faster to achieve equivalent compression ratio
Solution Approach 1:
The stator is divided into two separate rows of blades (first row and second row) arranged in tandem. The first row handles flow deflection while the second row completes the straightening operation. This segmentation allows each row to be optimized independently for its specific function, enabling the compressor to maintain effectiveness at reduced rotation speeds with fewer stages.
2Adaptability or versatility
If blade camber is increased to achieve greater flow deflection, then the flow straightening capability improves, but boundary layer separation occurs under adverse static pressure gradient
Solution Approach 1:
The total flow deflection task is segmented between two rows of stator blades. The first row handles the initial deflection with moderate camber, while the second row completes the straightening with optimized geometry. This distribution prevents any single blade from requiring excessive camber that would cause boundary layer separation.
Solution Approach 2:
Each row of blades is designed with specific local characteristics optimized for its particular function. The first row has geometry optimized for accommodating flow with strong incidence variation, while the second row is optimized for completing the deflection operation. This local optimization ensures reliable operation across the entire operating range.
3Adaptability or versatility
If variable-orientation blades are used to adapt to different operating points, then the compressor can manage varying incidence angles, but the aerodynamic load on blades increases significantly
Solution Approach 1:
The stator is segmented into two rows where the first row is specifically designed to accommodate flow with strong variation in incidence angle, while the second row completes the straightening operation. This segmentation allows the system to handle variable operating conditions without imposing excessive aerodynamic loads on individual blades.
4Device complexity
If a single row of stator blades is used for flow straightening, then the device complexity is reduced, but the ability to handle wide range of incidence angles is compromised
Solution Approach 1:
The stator is divided into two separate rows of blades arranged in tandem. The first row is optimized for accommodating flow with strong incidence variation, while the second row completes the straightening operation. This segmentation enables the system to handle a wide range of incidence angles that would be impossible for a single row to manage effectively.
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 tandem stator configuration improves airflow straightening and deflection across all operating points, reducing aerodynamic losses and enhancing surge margin while maintaining compressor efficiency.
Implementation Method 1
Transonic compressors are characterized by a significant load on the rotor and stator blades because they must accelerate and straighten an airflow over a shorter axial distance
Implementation Method 2
the camber of the blades must be significant, but too great a camber presents the risk of reaching boundary flow conditions, conditions in which the airflow separates from the blades under the effect of the adverse static pressure gradient
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a stator assembly (32) of a turbomachine, characterized in that it comprises: internal and external supports; two successive rows of stator blades (33, 35) defining a tandem configuration, comprising an annular row of upstream blades (33) extending substantially radially between the internal and external supports, and an annular row of downstream blades (35), located downstream of the upstream blades (33), extending substantially radially between the internal and external supports.