Tie Shaft Flow Trips for Compressor Convection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The dead air spaces between rotor stages in a compressor section of a gas turbine engine experience poor convection, leading to temperature increases due to the lack of airflow, which affects the efficiency and performance of the compressor section.
Innovation Solution
The introduction of radially extending flow trips or projections on the tie shaft, which deflect air into the dead air spaces between the rotor stages, enhancing convection and providing a cooling effect, are machined or welded onto the tie shaft to improve airflow and reduce temperature increases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If rotor stages are stacked discs connected by a tie shaft, then the compressor section structure is simplified and manufacturing is easier, but dead air spaces are created that reduce convection and increase temperature
Solution Approach 1:
The tie shaft is segmented with multiple radially extending projections that divide the dead air space into separate regions. These projections create flow paths that segment the stagnant air into manageable sections, allowing better heat dissipation through distributed convection rather than a single large dead space.
Solution Approach 2:
The radially extending projections act as intermediary structures between the tie shaft and the rotor stages. They mediate the airflow by deflecting it into the dead air spaces, converting the stagnant dead space into an active heat transfer region without requiring fundamental changes to the stacked disc structure.
2Device complexity
If dead air spaces exist between rotor stages, then the compressor section structure is simpler, but convection is reduced leading to temperature increases
Solution Approach 1:
Rather than completely eliminating the dead air spaces (which would require complex redesign), the invention applies partial action by adding projections that partially fill the dead spaces. This creates sufficient airflow disruption to improve convection while maintaining the overall simplicity of the stacked disc structure.
Solution Approach 2:
The solution adds a radial dimension to the airflow pattern by extending projections radially from the tie shaft. This transforms the primarily axial airflow into a combination of radial and axial flow components, enhancing convection in the dead air spaces without increasing axial complexity.
3Temperature
If flow trips are added to enhance convection, then temperature increases are reduced, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The flow trips (projections) are merged with the tie shaft structure itself, making the cooling function an integrated part of the structural component. This eliminates the need for separate cooling devices and reduces overall device complexity by combining structural support and thermal management functions in a single element.
Solution Approach 2:
The tie shaft projections serve multiple functions: they provide structural support as part of the rotor stage assembly and simultaneously act as flow trips to enhance convection. This multi-functionality reduces the need for additional dedicated cooling components, thereby limiting the increase in device complexity.
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 enhanced airflow through the compressor section reduces temperature increases and improves the efficiency and performance by increasing convection between the rotor stages, thus addressing the convection-related issues in the compressor section.
Implementation Method 1
The introduction of radially extending flow trips or projections on the tie shaft, which deflect air into the dead air spaces between the rotor stages, enhancing convection and providing a cooling effect
Data Source
Figure 1
Figure 2~3
AI summary
A compressor section according to an exemplary aspect of the present disclosure includes, among other things, a tie shaft assembly including a shaft and one or more projections extending radially outward from the shaft. The projections are configured to redirect air communicated from between the one or more rotor stages and the shaft.