Compressor Diffuser Pipes with Recirculation Conduits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In gas turbine engines, the rapid rise in static pressure and curvature of the flow path within diffuser pipes leads to low-momentum flow boundary buildup, limiting pressure gains, contributing to compressor stall and surge, and increasing mixing losses.
Innovation Solution
A diffuser system with recirculation conduits that extract part of the main gas flow from a high-pressure region and reinject it into a low-pressure region within the diffuser pipes, using a conduit inlet and outlet strategically located along the pipe's length to reduce low-momentum flow and prevent flow separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the diffuser pipes have a bend section to redirect flow from radial to axial direction, then the flow direction is changed effectively, but low-momentum flow boundary buildup occurs and pressure gains are limited
Solution Approach 1:
The patent extracts low-momentum boundary layer flow from the diffuser pipe through a tap, separates it from the main flow, and removes it via a recirculation conduit. This extraction prevents the low-momentum flow from causing boundary buildup and pressure loss, directly resolving the contradiction between effective flow redirection and pressure gain limitation.
Solution Approach 2:
The patent introduces an intermediary recirculation conduit system that mediates between the high-pressure main flow and the low-momentum boundary layer. The conduit acts as a mediator to transport extracted boundary layer flow away from the diffuser pipe, preventing harmful interactions while maintaining the beneficial flow direction change.
2Speed
If the diffuser pipes have a bend section to redirect flow, then flow direction is changed, but flow separation and compressor stall/surge occur
Solution Approach 1:
The patent extracts the unstable low-momentum boundary layer flow through a tap and removes it via the recirculation conduit before it can cause flow separation. This extraction eliminates the source of instability, preventing compressor stall and surge while maintaining the necessary flow direction change in the bend section.
Solution Approach 2:
The patent applies preliminary anti-action by extracting and removing the low-momentum boundary layer flow before it can develop into conditions that cause flow separation and compressor instability. The recirculation conduit proactively prevents the harmful effects before they manifest, ensuring flow stability.
3Speed
If the diffuser pipes have a bend section with rapid pressure rise, then flow is redirected axially, but mixing losses increase
Solution Approach 1:
The patent extracts the low-momentum boundary layer flow that would otherwise mix with the main flow and cause energy losses. By removing this boundary layer through the recirculation conduit, the patent prevents mixing losses while maintaining efficient axial flow redirection in the bend section.
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 approach enhances the resistance to flow separation and mixing losses, improving the overall performance of the diffuser by energizing the boundary layer and maintaining flow stability within the diffuser pipes.
Implementation Method 1
the recirculation conduit defining a recirculation path from a first flow region to a second flow region in one or more of the plurality of diffuser pipes, the first flow region having a greater static pressure than that of the second region
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A diffuser for a compressor of a gas turbine engine is disclosed. The diffuser has a plurality of diffuser pipes (40) circumferentially distributed about an axis of the compressor, each of the plurality of diffuser pipes (40) extending from an inlet to an outlet and having a bend section (45) between the inlet and the outlet, a low pressure side and an opposite high pressure side. A recirculation conduit (50) defines a recirculation path from a first flow region to a second flow region in one or more of the plurality of the diffuser pipes (40), the first flow region having a greater static pressure than that of the second region, the recirculation conduit (50) having a conduit inlet (51) and a conduit outlet (52), at least the conduit outlet (52) located within the low pressure side of one of the plurality of the diffuser pipes (40).