Air-Driven Augmentor Fan for High Bypass Propulsors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current high bypass ratio turbofan engines face challenges with weight, drag, noise, and integration issues, while open rotor propulsors offer better fuel efficiency but struggle with noise and integration complexities, necessitating a solution for improved fuel efficiency, low emissions, and reduced noise.
Innovation Solution
An air-driven augmentor fan system integrated with a turbofan engine, where the augmentor fan is driven by energized air from a ducted fan, optimizing blade count and configuration for reduced noise and increased effective bypass ratio, minimizing parasitic losses, and allowing independent rotation of the augmentor fan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If very high bypass ratio turbofans are used to reduce fuel burn, then fuel efficiency is improved, but weight and drag penalties increase due to very large nacelles
Solution Approach 1:
The propulsor is segmented into two independent rotating components: a ducted fan driven by the core engine and an augmentor fan that rotates independently. This segmentation allows the bypass airflow to be divided into two streams, enabling high effective bypass ratio without requiring a single oversized nacelle, thus reducing weight and drag penalties
Solution Approach 2:
The augmentor fan acts as an intermediary component that utilizes the kinetic energy from the ducted fan's bypass airflow to drive a second set of blades. This intermediary mechanism extracts additional thrust from the bypass stream without requiring a larger core engine or oversized nacelle, achieving high fuel efficiency with reduced weight
2Use of energy by moving object
If very high bypass ratio turbofans are used to reduce fuel burn, then fuel efficiency is improved, but noise levels increase
Solution Approach 1:
By segmenting the bypass flow into two separate rotating blade systems (ducted fan and augmentor fan), the noise generation is distributed across two different rotational speeds and blade configurations. This segmentation allows optimization of each stage to reduce overall noise while maintaining high bypass ratio for fuel efficiency
Solution Approach 2:
The augmentor fan operates at a different rotational speed and blade configuration than the ducted fan, changing the operational parameters of the bypass flow. This parameter change allows the second stage to extract thrust in a manner that reduces noise emissions while maintaining the high effective bypass ratio needed for fuel efficiency
3Use of energy by moving object
If open rotor propulsors are used to achieve higher effective bypass ratio, then fuel burn is reduced, but integration challenges and drag penalties occur
Solution Approach 1:
The invention merges the benefits of open rotor high effective bypass ratio with the advantages of a ducted configuration. The augmentor fan is integrated within the nacelle structure, combining the open rotor concept with ducted protection, simplifying integration while maintaining high fuel efficiency and reducing drag penalties
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 air-driven augmentor fan system achieves reduced fuel burn, lower noise levels, and improved integration by optimizing blade configuration and operation across a wide range of speeds, while minimizing noise and drag penalties.
Implementation Method 1
a bypass flow path in communication with a ducted fan of the turbofan engine such that the bypass flow path accelerates air through the ducted fan
Implementation Method 2
an exhaust system in communication with the augmentor fan such that the exhaust system directs an air stream onto the augmentor fan to rotate the augmentor fan
Data Source
AI summary
Systems and methods are provided for an air-driven augmentor fan equipped aircraft propulsor. The augmentor fan may increase the effective bypass ratio of the aircraft propulsor and reduce fuel consumption and carbon emissions of the aircraft. The augmentor fan may be driven by air energized by a ducted fan powered by the core engine of the aircraft propulsor. The energized air may be received by an inlet, flowed through a flow path, and exhausted out the outlet to drive the augmentor fan. The exhausted energized air may impart a torque on the augmentor fan or blades of the augmentor fan. One or more of the inlet, flow path, or outlet may be variable in size to control the volume of air flowed through the flow path.