Segmented Turbine Diffuser Flowpath Surfaces
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Solution Overview
Problem
Current diffuser designs in turbine engines are limited in reducing air flow loss and improving combustion stabilization, leading to longer engine lengths and increased pressure losses, which can result in flame-outs and decreased engine part life due to rapid boundary layer growth and separation.
Innovation Solution
The implementation of a multi-layered flow diffuser with strategically positioned flowpath surfaces supported by struts and airfoil shapes, enabling more aggressive diffusion in a reduced axial length, and incorporating boundary layer control and suction to mitigate pressure losses and recirculation zones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If traditional diffuser designs are used, then air flow diffusion occurs, but the diffusion rate is limited to prevent boundary layer separation, resulting in longer diffuser sections and increased engine length
Solution Approach 1:
The diffuser section is divided into multiple zones with different diffusion angles. The first zone has a smaller diffusion angle to prevent boundary layer separation, while the second zone has a larger diffusion angle to achieve rapid diffusion. This segmentation allows each zone to optimize its diffusion rate according to local flow conditions, enabling faster overall diffusion without causing separation.
Solution Approach 2:
Different portions of the diffuser are given different geometric properties - specifically, different diffusion angles in different axial zones. The upstream portion uses a conservative angle suitable for boundary layer stability, while the downstream portion uses an aggressive angle for rapid diffusion. This local differentiation resolves the contradiction by applying appropriate diffusion rates where needed.
2Reliability
If diffuser section is extended to reduce air flow loss, then combustion stabilization improves, but engine length and weight increase
Solution Approach 1:
The extended diffuser is segmented into zones with varying diffusion angles, allowing rapid diffusion in the second zone while maintaining stability in the first zone. This enables achieving adequate combustion stabilization through controlled diffusion without requiring an excessively long diffuser section, thus reducing overall engine length.
Solution Approach 2:
The patent introduces radial positioning of flowpath surfaces at different radial spans, adding a radial dimension to the diffusion control. This multi-dimensional approach (axial zones combined with radial positioning) enables more aggressive diffusion in reduced axial length while maintaining combustion stability, avoiding the need for long engine extensions.
3Use of energy by moving object
If diffuser section is extended to reduce air flow loss, then combustion efficiency improves, but engine weight increases
Solution Approach 1:
By segmenting the diffuser into zones with optimized diffusion angles, the patent achieves effective air flow diffusion and combustion efficiency improvement without requiring excessive diffuser length. This reduces the amount of material needed for the diffuser structure and overall engine components, thereby reducing engine weight while maintaining combustion efficiency.
4Speed
If aggressive diffusion is implemented, then diffusion rate increases, but boundary layer separation and pressure losses occur
Solution Approach 1:
The diffuser is segmented into a first zone with a smaller diffusion angle designed to prevent boundary layer separation and minimize pressure losses, and a second zone with a larger diffusion angle that provides aggressive diffusion. This segmentation allows the system to achieve high diffusion rates in the second zone without incurring the penalties of separation and pressure loss that would occur with uniformly aggressive diffusion throughout.
Solution Approach 2:
Different local regions of the diffuser are assigned different diffusion angles appropriate to their position and flow conditions. The upstream region uses a gentler angle to maintain attached flow and minimize losses, while downstream regions use steeper angles for rapid diffusion. This local optimization resolves the contradiction between aggressive diffusion and pressure loss prevention.
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
This solution allows for more rapid airflow diffusion at lower pressure losses, reducing engine length, weight, and enhancing aerodynamic performance while maintaining stable combustion, thereby improving engine efficiency and reducing the risk of catastrophic failures.
Implementation Method 1
control diffusion of air flow in an axial direction
Implementation Method 2
incorporating boundary layer control and suction to mitigate pressure losses and recirculation zones
Data Source
AI summary
Diffuser apparatus for turbine frames and outlet guide vanes are disclosed. An example diffuser is integrated into a turbine engine. The example diffuser includes a plurality of struts extending between an inner portion and an outer portion of the turbine engine; and a plurality of flowpath surfaces supported by the plurality of struts. The example plurality of flowpath surfaces extends circumferentially within the turbine engine at a plurality of radial spans to control diffusion of air flow within the turbine engine.