Stowage Tube Door Mechanism for Hypersonic Store Ejection
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Solution Overview
Problem
Traditional store deployment methods are impractical for hypersonic aircraft due to extreme air-loads and temperatures, which cause aerodynamic and acoustic shocks, and heat generation, making it difficult to safely release stores during flight.
Innovation Solution
A system featuring a stowage tube with an open rear end and a door panel actuated by an actuator-driven linkage, coupled with an ejector valve that uses pressurized fluid to eject stores rearwardly, reducing aerodynamic forces and ensuring high end-of-stroke velocity, thereby mitigating the challenges of hypersonic flight conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional door deployment methods are used for store release, then the system is simple and reliable, but extreme air-loads and temperatures during hypersonic flight cause aerodynamic shocks and make deployment impossible
Solution Approach 1:
The store is extracted from the traditional bay configuration and placed in a stowage tube positioned in the aircraft's wake region. This extraction removes the store from the high-stress aerodynamic environment near the aircraft body, allowing deployment without exposure to extreme air-loads and temperatures that would damage traditional door systems.
Solution Approach 2:
The deployment mechanism transitions from inboard/outboard door rotation about a longitudinal axis to a rearward ejection mechanism. The door panel rotates about a lateral axis positioned at the forward edge of the stowage tube, changing the deployment dimension from lateral to rearward, which eliminates exposure to hypersonic aerodynamic shocks.
2Temperature
If the door panel is positioned to shield stores from air streams, then thermal protection is achieved, but the door must rotate about a forward edge pivot axis requiring complex actuation
Solution Approach 1:
The door panel is pre-positioned in a closed configuration that shields the stowage tube and store from hot air streams during hypersonic flight. The actuator driven linkage is pre-configured with a lateral pivot axis at the forward edge, allowing the door to rotate into a protective position before thermal exposure becomes critical.
Solution Approach 2:
The actuator driven linkage serves as an intermediary mechanism between the actuator and the door panel. It translates actuator motion into door panel rotation about the lateral axis, providing mechanical advantage and precise control while accommodating the complex motion requirements of the deployment system.
3Object-affected harmful factors
If stores are ejected rearwardly from the stowage tube, then aerodynamic forces are reduced and deployment is feasible, but high ejection velocity is required for safe separation
Solution Approach 1:
The ejection system uses periodic action through the actuator driven linkage that rotates the door panel to an open position, followed by piston-driven ejection. The regulating orifice creates a controlled, progressive flow of pressurized fluid that builds pressure over time, accelerating the store to high velocity in a controlled manner for safe separation.
Solution Approach 2:
The ejection mechanism employs pneumatic principles using a piston and pressurized fluid system. The regulating orifice controls fluid flow to the piston chamber, generating high pressure that drives the piston to eject the store rearwardly at high velocity. This pneumatic system achieves the required end-of-stroke velocity for safe store separation while minimizing aerodynamic forces.
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 system enables safe and efficient deployment of stores from hypersonic aircraft by reducing the impact on the aircraft's mold line and shielding the stores from air streams, achieving continuous aerodynamic sealing and thermal protection while ensuring high end-of-stroke velocities for safe separation.
Implementation Method 1
The ejector valve provides pressurized fluid to move the piston to eject the store
Implementation Method 2
The ejector valve includes a regulating orifice sized to controllably regulate flow of the pressurized fluid to cause an applied force to the piston to increase with stroke
Implementation Method 3
An actuator driven linkage is coupled to the door panel. The actuator driven linkage is configured to rotate the door panel about a pivot axis at a forward edge
Data Source
AI summary
A system and method for ejecting a store from an aircraft include a stowage tube configured to retain the store. The stowage tube includes an open rear end. A door panel is coupled to the stowage tube. An actuator driven linkage is coupled to the door panel. The actuator driven linkage is configured to rotate the door panel about a pivot axis at a forward edge opposite from an aft end between a closed position associated with a stowed position of the system and an open position associated with a deployed position of the system. The stowage tube is configured to rearwardly eject the store out of the open rear end when the system is in the deployed position.