Gas Turbine Compressor Arrangement with Gear-Driven Fan
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engine compressor designs face inefficiencies due to relative movement between compressor portions, which decreases compression efficiency and complicates access to plumbing connections, particularly when the inlet case supports the compressor.
Innovation Solution
A gas turbine engine configuration featuring a gear arrangement to drive the fan section, with a low pressure turbine driving both the low pressure compressor and fan, and a high pressure turbine driving the high pressure compressor, along with a support member to restrict movement between the compressor case and inlet case, allowing for improved compression ratios and simplified maintenance access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the inlet case supports the front portion of the compressor, then the compressor is supported during fan movement, but relative movement between compressor portions varies rotor tip clearances and decreases compression efficiency
Solution Approach 1:
The compressor is divided into front and rear portions, each supported by separate structures (inlet case and intermediate case respectively). This segmentation allows independent support and positioning of each compressor section, preventing relative movement between portions while maintaining manufacturing precision of rotor tip clearances.
2Strength
If the inlet case supports the compressor, then structural support is provided, but access to plumbing connections near the inlet case is complicated
Solution Approach 1:
The plumbing connections are extracted from the inlet case structure and repositioned to the intermediate case or other accessible locations. This allows the inlet case to maintain its structural support function while plumbing connections become accessible for maintenance and operation.
3Device complexity
If a low pressure turbine drives both the low pressure compressor and fan, then device complexity is reduced, but different speeds are required for optimal performance
Solution Approach 1:
A gear reduction mechanism is introduced between the low pressure turbine and the fan, allowing the fan to rotate at a different speed than the compressor. This dynamic speed adjustment enables both the compressor and fan to operate at their optimal speeds while being driven by a single turbine, reducing overall device complexity compared to multiple turbines.
Data Source
AI summary
A gas turbine engine has a fan section, a gear arrangement configured to drive the fan section, a compressor section, including both a low pressure compressor section and a high pressure compressor section. A turbine section is configured to drive the compressor section and the gear arrangement. An overall pressure ratio provided by the combination of a pressure ratio across the low pressure compressor section and a pressure ratio across the high pressure compressor section is greater than about 35. The pressure ratio across a first of the low and high pressure compressor sections is between about 3 and about 8. The pressure ratio across a second of the low and high pressure compressor sections is between about 7 and about 15. The fan is configured to deliver a portion of air into the compressor section, and a portion of air into a bypass duct.