Closable Turboprop Engine Core to Prevent Windmilling
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Solution Overview
Problem
Existing aircraft engines face challenges in preventing windmilling when powered off during flight, which can cause wear and restarting difficulties due to excessive airflow, leading to spillage drag and core rotation without lubrication.
Innovation Solution
Aircraft engines are equipped with a blocking member that can move between open and closed positions to isolate the core from airflow, using a nacelle intake and exhaust to control airflow, preventing windmilling and maintaining engine integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the engine core remains open during flight when powered off, then the engine can be restarted quickly, but the core will windmill and rotate without lubrication causing wear and damage
Solution Approach 1:
The patent divides the engine core from the external environment by introducing a blocking member that can isolate the core components (compressor, combustor, turbine) from airflow. This segmentation allows the core to be protected from windmilling while maintaining the ability to reconnect when needed for restart.
Solution Approach 2:
The blocking member is positioned and configured in advance within the engine nacelle to prevent windmilling before it occurs. The system proactively closes the core during idle flight conditions, preventing the harmful rotation rather than reacting to it after it starts.
2Object-affected harmful factors
If a blocking member is introduced to prevent windmilling, then core protection is improved, but device complexity increases
Solution Approach 1:
The blocking member is extracted as a separate, independent component from the main engine structure. It is positioned in the nacelle airflow path rather than integrated into the core rotating assembly, simplifying its design and operation while achieving the windmilling prevention function.
Solution Approach 2:
The blocking member acts as an intermediary element between the external airflow and the engine core. Rather than modifying the core itself or the external environment, this mediator component controls the interaction between airflow and core, preventing harmful effects while maintaining system simplicity.
Data Source
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AI summary
An aircraft engine (10), has: a core having a compressor (13), a combustor (14), and a turbine (15) disposed in serial flow communication, the turbine (15) in driving engagement with a propeller (17); a nacelle (100) extending around the core, the nacelle (100) having a nacelle intake (101) upstream of the core and a nacelle exhaust (120) downstream of the core, the nacelle intake (101) configured for receiving air from an environment outside the nacelle (100), the nacelle intake (101) fluidly connected to the compressor (13) for feeding air thereto, the nacelle exhaust (120) configured to discharge combustion gases from the turbine (15) into the environment outside the nacelle (100); and a blocking member (104) movable between an open position in which the core is fluidly connected to the environment via both the nacelle (100) intake (101) and the nacelle exhaust (120), and a closed position in which the blocking member (104) hinders fluid communication between the core and the environment via one of the nacelle (100) intake (101) and the nacelle exhaust (120).