Drogue Assembly Dual Canopy Variable Drag
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Solution Overview
Problem
Existing drogue assemblies for in-flight refueling face challenges in maintaining stable drag loads across a broad range of airspeeds, from low-speed to high-speed aircraft, as drag load varies proportionally to the square of airspeed, requiring different drogue sizes and posing risks of probe damage and increased power requirements.
Innovation Solution
A drogue assembly with a dual canopy system, where a first canopy provides a fixed or variable area and a second canopy folds inwardly towards the first at higher speeds, adjusting its effective area to maintain stable drag loads, comprising a reception coupling member with a drogue parachute and a foldable parachute with support arms and springs that adjust under air pressure, allowing the drogue to maintain a compact size at high speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a drogue parachute is used to provide drag for stabilizing the refueling hose, then the refueling coupling is stabilized and drag force is provided, but the drag load varies proportionally to the square of airspeed causing probe damage risk and increased power requirements
Solution Approach 1:
The drogue assembly employs a dual canopy system where the second canopy is configured to fold inwardly towards the first canopy under air pressure loading at higher speeds. This dynamic configuration change allows the effective area to vary with airspeed, automatically reducing drag load at high speeds while maintaining sufficient drag at low speeds for hose stabilization.
Solution Approach 2:
The invention changes the effective area parameter of the drogue parachute by incorporating a second canopy that folds inwardly at higher speeds. This parameter change enables the drag force to remain substantially stable across a broad range of airspeeds, resolving the contradiction between providing sufficient drag for stabilization and avoiding excessive drag at high speeds.
2Object-affected harmful factors
If a small drogue is used to meet high speed aircraft geometry requirements, then probe damage is prevented, but insufficient drag is produced at low speeds
Solution Approach 1:
The dual canopy system with the foldable second canopy provides a dynamic solution where the effective area can be large at low speeds to generate sufficient drag, and automatically reduces at high speeds to prevent probe damage. This resolves the contradiction between needing large drag at low speeds and limiting drag at high speeds.
3Force
If different sized drogues are used for different airspeed ranges, then optimal drag is achieved for each speed range, but device complexity and the need for multiple components increases
Solution Approach 1:
The invention merges two canopy systems into a single integrated drogue assembly. The first canopy provides a fixed or variable area, while the second canopy is configured to fold inwardly towards the first. This combination allows a single drogue assembly to provide optimal drag performance across both low and high speed ranges, eliminating the need for separate drogues for different speed ranges.
Solution Approach 2:
The dual canopy drogue assembly serves multiple functions: at low speeds, both canopies are deployed to provide large effective area and sufficient drag; at high speeds, the second canopy folds inwardly to reduce effective area and prevent excessive drag. This multi-functional design allows a single device to adapt to different operating 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
The dual canopy system automatically adjusts to maintain stable drag forces across varying airspeeds, enabling the same refueling equipment to be used for both low-speed and high-speed aircraft without increasing the drogue's size or envelope, thus minimizing power requirements and preventing probe damage.
Implementation Method 1
the second canopy having a configuration which is arranged to change under air pressure loading on the canopy in flight such that the second canopy folds inwardly towards the first canopy
Data Source
AI summary
A drogue assembly includes a probe guide such as a standard small high speed drogue with a first canopy (14), and a foldable second canopy (20) mounted around the first canopy which is biased outwardly, and is foldable inwardly under air pressure loading to overlie the small drogue at low speeds. Thus the drag produced by the drogue varies automatically with airspeed allowing the assembly to be used over a wide range of airspeeds.