Turbomachine Compressor Diffuser Bleed Holes for Uniform Exit Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbomachines, such as gas turbine engines, face nonuniformity in airflow due to bleed air extraction, which can lead to suboptimal combustor performance and reduced turbine durability due to inconsistent air flow patterns.
Innovation Solution
The configuration of bleed holes of varying sizes distributed circumferentially around the diffuser to ensure uniform compressor exit flow distribution, minimizing disruption to the airflow and maintaining acceptable plenum pressure drops, thereby directing bleed air away from the combustor to achieve consistent airflow to the combustor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If bleed air is extracted from the compressor section, then air can be supplied for various purposes (e.g., anti-ice, pneumatic systems), but nonuniformity is introduced in the airflow leaving the compressor section
Solution Approach 1:
The patent applies local quality by varying the size of individual bleed holes based on their circumferential position. Bleed holes are made larger in regions where more bleed air is needed and smaller in regions where less bleed air is needed, thereby compensating for the nonuniformity introduced by bleed extraction and maintaining uniform airflow to the combustor
Solution Approach 2:
The patent changes the parameter of bleed hole size (diameter or area) to optimize airflow distribution. By adjusting the size parameter of each bleed hole, the system compensates for variations in bleed air demand around the circumference and maintains uniform compressor exit flow distribution
2Reliability
If bleed holes are configured to provide uniform compressor exit flow distribution, then combustor performance is optimized, but device complexity increases due to varying hole sizes
Solution Approach 1:
The patent implements local quality by distributing different bleed hole sizes at specific circumferential locations. This allows the system to maintain simple overall structure while achieving uniform airflow distribution through localized variations in hole size, optimizing combustor performance without excessive complexity
3Stability of the object's composition
If bleed air is directed away from the combustor, then consistent airflow is delivered to the combustor, but pressure drop in the plenum increases
Solution Approach 1:
The patent optimizes the size parameter of bleed holes to balance airflow consistency and pressure drop. By carefully selecting bleed hole sizes, the system achieves uniform compressor exit flow distribution while minimizing plenum pressure drop to acceptable levels (less than 5 psid/34.5kPa)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A turbomachine 20 includes a compressor 44, a combustor 56 disposed to receive the compressed air from the compressor through a flow path, and a diffuser 38 disposed in the flow path between the compressor and the combustor. A number of bleed holes 101 are disposed downstream in the flow path from the diffuser 38 and are configured to direct bleed air compressed by the compressor away from the combustor. The number of bleed holes 101 have a plural number of sizes configured to provide uniform compressor exit flow distribution around a circumference of the diffuser 38.