Core Auxiliary Duct Passage for Gas Turbine Noise Reduction
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Solution Overview
Problem
Mixed flow turbofan engines face challenges in achieving improved efficiency and noise reductions, with existing attempts being unsuccessful and complex or costly.
Innovation Solution
A gas turbine engine system with a core auxiliary duct passage that selectively diverts a portion of the core airflow based on operability conditions, increasing the bypass ratio and reducing noise by controlling the inlet and outlet of the auxiliary duct passage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If attempts are made to increase the beneficial results of mixed flow turbofan engines, then noise reductions and propulsion efficiency may be improved, but device complexity and cost increase
Solution Approach 1:
The core airflow is segmented into two separate paths: a primary path through the core passage and a secondary path through the auxiliary duct passage. This segmentation allows selective diversion of core airflow to the fan bypass passage, enabling noise reduction during specific operability conditions without permanently complicating the overall engine structure.
Solution Approach 2:
The auxiliary duct passage incorporates movable inlet and outlet components that can be dynamically positioned based on operability conditions. This dynamic adjustment allows the system to optimize noise reduction and efficiency only when needed, rather than maintaining a permanently complex configuration.
2Productivity
If attempts are made to increase the beneficial results of mixed flow turbofan engines, then propulsion efficiency may be improved, but device complexity and cost increase
Solution Approach 1:
The core airflow is segmented into two separate paths: a primary path through the core passage and a secondary path through the auxiliary duct passage. This segmentation allows selective diversion of core airflow to the fan bypass passage, enabling efficiency improvement during specific operability conditions without permanently complicating the overall engine structure.
Solution Approach 2:
The system changes the bypass ratio parameter dynamically by diverting core airflow through the auxiliary duct passage when beneficial for efficiency. This allows the engine to operate at optimized bypass ratios under specific conditions without requiring a permanently complex variable geometry system.
3Object-affected harmful factors
If core airflow is diverted through the auxiliary duct passage, then bypass ratio increases and noise reduces, but backpressure may increase
Solution Approach 1:
The auxiliary duct passage is designed with specific local characteristics including strategically positioned inlet and outlet locations, and appropriate passage geometry. These local quality features allow the diverted core airflow to mix with fan bypass airflow effectively without creating excessive backpressure that would harm engine performance.
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 solution enhances engine efficiency and reduces noise by increasing the bypass ratio and minimizing backpressure, while being relatively inexpensive and non-complex to implement.
Implementation Method 1
a core auxiliary duct passage that selectively diverts a portion of the core airflow
Data Source
AI summary
A gas turbine engine system includes a nacelle assembly, a core engine and a mixer disposed between the nacelle assembly and the core engine. The core engine includes a core passage and a core auxiliary duct passage. The core auxiliary duct passage includes an inlet for receiving a portion of a core airflow form the core engine and an outlet for discharging a portion of the core airflow received from the core engine.