Rotor Blade Foam Core Injection Method
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Solution Overview
Problem
Conventional rotor blade manufacturing methods face challenges in efficiently and cost-effectively filling the core area with foam materials, leading to issues such as voids, disbonds, and increased manufacturing time and cost, particularly due to tolerance variations and the need for pre-machined core materials.
Innovation Solution
A method involving the use of a liquid foam mixture that expands to fill the hollow core area of a rotor blade, adhering to the inner surfaces and structural components, eliminating the need for pre-machined cores and reducing manufacturing steps by injecting or pouring the foam through strategically positioned openings and using a foam delivery system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pre-machined core materials are used to fill the rotor blade core area, then manufacturing precision is improved, but device complexity and manufacturing time increase
Solution Approach 1:
The patent changes the physical state parameter of the foam material from solid (pre-machined) to liquid (injectable foam mixture). The liquid foam is injected into the core area and then undergoes phase transition to solid foam, eliminating the need for pre-machining while achieving complete void-free filling and full bond line contact with skin components.
Solution Approach 2:
The patent uses a foam delivery system with injection nozzles to deliver the liquid foam mixture into the core area through controlled fluid injection. This hydraulic/pneumatic delivery method enables precise control of foam placement and distribution without requiring complex mechanical machining operations.
2Ease of manufacture
If conventional foam filling methods are used, then manufacturing cost is reduced, but manufacturing time and productivity are worsened
Solution Approach 1:
The patent implements continuous foam injection through multiple nozzles positioned at different locations in the core area. The liquid foam is continuously delivered and expands to fill the entire core volume in one continuous operation, eliminating the need for multiple discrete steps such as placing pre-machined core pieces and bonding them separately.
Solution Approach 2:
The patent divides the foam delivery system into multiple independent nozzles positioned at different locations within the core area. This segmentation allows simultaneous or sequential injection at multiple points, ensuring complete and uniform filling of large or complex core geometries while maintaining continuous operation.
3Productivity
If liquid foam mixture is injected to fill the core area, then manufacturing time is reduced, but manufacturing precision may worsen due to potential voids and improper expansion
Solution Approach 1:
The patent incorporates feedback control through pressure sensors and flow meters in the foam delivery system. The system monitors injection pressure, flow rate, and foam expansion characteristics in real-time, automatically adjusting injection parameters to ensure complete filling without voids and achieve the desired foam density and uniformity in the core area.
Solution Approach 2:
The patent performs preliminary positioning of multiple nozzles at optimal locations within the core area before injection begins. The nozzle positions and injection sequences are pre-planned based on core geometry analysis, ensuring that foam is delivered to all critical areas in the correct sequence to prevent void formation and achieve uniform expansion throughout the core volume.
4Reliability
If multiple nozzles are used for foam injection at different distances, then filling completeness is improved, but device complexity increases
Solution Approach 1:
The patent designs the foam delivery system with multiple nozzles that can function independently or in combination. Each nozzle is capable of delivering foam to different regions of the core area, and the system can adapt its operation mode (single nozzle, multiple nozzles simultaneous, or sequential activation) based on the specific core geometry and size, providing universal applicability across different rotor blade designs.
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 approach ensures a full bond line between the core and skin components, eliminates voids, and reduces manufacturing time and cost by forming a solid foam core in-place, which is repeatable and certifiable for quality control criteria, even in complex geometries and large rotor blades.
Implementation Method 1
providing, via the at least one nozzle, a liquid foam mixture in the hollow portion, wherein the liquid foam expands and becomes a solid foam material that fills the hollow portion of the rotor blade
Implementation Method 2
The solid foam material may adhere to an upper skin of the rotor blade, a lower skin of the rotor blade, a spar of the rotor blade, and a trailing edge wedge of the rotor blade
Data Source
AI summary
A method is provided in one example embodiment and may include positioning at least one nozzle within a hollow portion of a rotor blade at a distance associated with a span of the rotor blade and providing, via the at least one nozzle, a liquid foam mixture in the hollow portion, wherein the liquid foam expands and becomes a solid foam material that fills the hollow portion of the rotor blade. Another method is provided in another example embodiment and may include providing a plurality of openings for a rotor blade that are positioned proximate to a hollow portion of the rotor blade and providing a liquid foam mixture in the hollow portion of the rotor blade through at least one opening of the rotor blade, wherein the liquid foam mixture expands and becomes a solid foam material that fills the hollow portion of the rotor blade.