Reverse Core Flow Gas Turbine Engine Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Reverse core flow gas turbine engines seek to enhance efficiency beyond existing designs, which typically have limitations in energy extraction and propulsion due to conventional axial arrangements of compressor, combustor, and turbine sections.
Innovation Solution
The engine incorporates a core section with low and high-pressure compressors and turbines on concentric spools, a combustor between the high-pressure compressor and turbine, and a propulsor section with a geared architecture that includes an epicyclic gear train to drive the fan section, along with an intercooler extending more than 50% of the core section's axial length for improved cooling and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional axial arrangement of compressor, combustor, and turbine sections is used, then the engine structure is simple, but the energy extraction and propulsion efficiency is limited
Solution Approach 1:
The patent inverts the conventional axial flow direction by implementing a reverse core flow configuration where the core flow turns 180 degrees to flow forward through the turbine sections, opposite to the typical rearward flow direction. This inversion allows for improved energy extraction and propulsion efficiency while maintaining a relatively simple overall engine structure.
Solution Approach 2:
The patent introduces a three-dimensional flow path configuration with reverse flow ducts that redirect the core flow in a different spatial dimension (180-degree turn from axial rearward flow to axial forward flow). This dimensional change enables enhanced thermodynamic efficiency without significantly increasing the linear footprint of the engine.
2Productivity
If the core flow is turned 180° to flow forward through the turbine sections, then the propulsion efficiency is improved, but the engine structure becomes more complex
Solution Approach 1:
The patent employs nested concentric spool arrangements where the high-speed core spool is positioned within the low-speed core spool, and the turbine sections are integrated within the reverse flow duct structure. This nesting approach consolidates multiple components into a compact configuration, reducing overall structural complexity despite the inverted flow path.
Solution Approach 2:
The patent merges the reverse flow duct structure with the turbine section housing and integrates the concentric spools into a unified assembly. By combining multiple functional elements into integrated structures, the patent reduces the number of separate components and simplifies the overall engine architecture while maintaining the beneficial reverse flow configuration.
3Length of moving object
If low and high pressure core compressors and turbines are mounted on concentric spools, then the spool axial distance is minimized, but the manufacturing complexity increases
Solution Approach 1:
The patent implements nested concentric spool arrangements where the high-speed core spool with its turbine and compressor is positioned within the low-speed core spool assembly. This nesting minimizes the axial distance between compressor and turbine sections while consolidating multiple rotating components into a compact configuration that reduces manufacturing complexity compared to separate assemblies.
4Temperature
If an intercooler extending more than 50% of the core section axial length is used, then the cooling efficiency is improved, but the engine length increases
Solution Approach 1:
The patent integrates the intercooler into the reverse flow duct structure, utilizing the three-dimensional space created by the inverted flow path. The intercooler extends along more than 50% of the core section axial length within the available space of the reverse flow configuration, achieving enhanced cooling efficiency without proportionally increasing the overall engine length, as the intercooler is accommodated within the existing structural envelope.
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 configuration achieves a high overall pressure ratio of 100 or greater, minimizing spool axial distance and reducing structural bending, while maintaining aerodynamic efficiency and providing significant thrust through a high bypass ratio, thus improving engine efficiency and reducing costs.
Implementation Method 1
an intercooler extending more than 50% of the core section's axial length for improved cooling and efficiency
Implementation Method 2
air is mixed with fuel and burned in the combustor section to generate hot combustion gases
Implementation Method 3
The hot combustion gases are communicated through the turbine section, which extracts energy from the hot combustion gases to power the compressor section and other gas turbine engine loads
Implementation Method 4
air is pressurized in the compressor section
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A reverse flow gas turbine engine (10) includes a propulsor section (14) which includes a propulsor compressor section (44) and a propulsor turbine section (46). The propulsor section (14) includes a fan section (42) and a geared architecture (60). The fan section (42) is driven by the propulsor turbine section (46). A core section (12) is arranged fluidly between the propulsor compressor section (44) and the propulsor turbine section (46). The core section (12) includes a reverse flow duct (64) that reverses a core flow through the core section (12). At least one of the propulsor section (14) and the core section (12) has a two-spool arrangement.