Propeller Dynamic Scoop for Blade Root Cooling
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Solution Overview
Problem
The existing cooling and ventilation systems for unducted propeller blade roots in turbomachines, particularly those made of composite materials, face challenges in achieving effective cooling under low Mach number pressure conditions, leading to overheating issues and increased aerodynamic drag and noise due to the reliance on dynamic scoops that are either insufficient during idling and takeoff or unnecessary during high-speed phases.
Innovation Solution
A dynamic scoop mechanism that can adjust its position based on blade orientation and speed, deploying only during critical phases like idling and takeoff to capture ventilation air, and retracting during high-speed operations to minimize aerodynamic drag and noise, utilizing centrifugal force and a counterweight system for operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a dynamic scoop is used to capture ventilation air for cooling blade roots, then cooling effectiveness is improved during low-speed phases, but aerodynamic drag and noise increase during high-speed operations
Solution Approach 1:
The scoop is designed to be movable rather than fixed, capable of deploying and retracting based on operational conditions. During low-speed phases (idling, takeoff), the scoop deploys to capture ventilation air for blade root cooling. During high-speed phases, the scoop retracts to minimize aerodynamic drag and noise, dynamically adapting to operational requirements.
Solution Approach 2:
The scoop operates periodically, deploying only during specific flight phases when cooling is needed (low-speed phases) and retracting during other phases (high-speed operations). This periodic deployment pattern ensures cooling effectiveness when required while eliminating harmful drag and noise when the scoop is not needed.
2Reliability
If a dynamic scoop is deployed to ensure adequate ventilation air supply during idling and takeoff, then cooling reliability is improved, but device complexity increases
Solution Approach 1:
The scoop mechanism incorporates a counterweight system that automatically controls deployment and retraction based on blade orientation and centrifugal force. The counterweight balances the scoop's weight and utilizes gravitational and centrifugal forces to trigger deployment during low-speed phases when the blade is in specific orientations, ensuring reliable cooling without complex control systems.
Solution Approach 2:
The scoop system is designed to be self-actuating, using the blade's own rotation, centrifugal force, and gravitational effects to automatically deploy and retract the scoop. The counterweight mechanism converts the blade's rotational motion into automatic scoop deployment during appropriate phases, eliminating the need for external control systems or additional actuators.
3Productivity
If the scoop is designed to capture airflow effectively at low Mach numbers, then ventilation performance is improved, but aerodynamic drag increases at high Mach numbers
Solution Approach 1:
The scoop's geometry and position are dynamically adjusted based on Mach number and flight phase. At low Mach numbers during idling and takeoff, the scoop is deployed in an optimal position to maximize ventilation air capture efficiency. At high Mach numbers during cruise, the scoop retracts or adjusts its angle to minimize aerodynamic drag, adapting its configuration to the prevailing flight conditions.
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 solution allows for effective ventilation and cooling of blade roots without generating harmful aerodynamic or acoustic effects, optimizing airflow during specific flight phases and reducing unnecessary drag and noise at high speeds.
Implementation Method 1
utilizing centrifugal force and a counterweight system for operation
Implementation Method 2
utilizing centrifugal force and a counterweight system for operation
Data Source
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AI summary
The main subject matter of the invention is a propeller (32) for a turbomachine (1) comprising a plurality of blades (48) and a blade support ring (47) provided with housings (50) each receiving a pivot (52) carrying the root (58) of one of said blades (48), characterised in that at least one of the pivots (52) is combined with at least one dynamic scoop (100), which is designed to be movable between an open position for capturing a cooling air flow (F), and a different closed position, on the basis of the orientation of the corresponding blade (48).