Deflectable Flaps for Thrust Vectoring and Boosting
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Solution Overview
Problem
Conventional attitude control and thrust vectoring systems for space launchers face challenges such as high complexity, cost, and reduced dynamic performance due to the need for flexible joints or universal joints in solid and liquid propellant rocket engines, and are affected by impulse loads during engine ignition.
Innovation Solution
A system with fixed exhaust nozzles and flaps around the exit section that can be actuated to control attitude and boost thrust by varying their angular position based on ambient static pressure and actual attitude, eliminating mechanical interfaces with the nozzle and reducing inertial loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional TVC systems use flexible joints or universal joints to deflect the nozzle, then attitude control is achieved, but device complexity and manufacturing cost increase significantly
Solution Approach 1:
The system segments the attitude control function from the nozzle itself. Instead of making the nozzle movable through complex joints, the invention introduces separate deflectable flaps at the nozzle exit that can be independently controlled to achieve the same thrust vectoring effect, thereby simplifying the nozzle structure while maintaining attitude control capability.
Solution Approach 2:
The deflectable flaps act as an intermediary element between the fixed nozzle and the desired thrust direction. These flaps intercept and redirect the exhaust flow to produce the required control torque, eliminating the need for complex mechanical joints while achieving the same functional outcome.
2Ease of operation
If the nozzle is made movable to enable attitude control, then thrust direction can be varied, but the inertial value of the load increases, limiting dynamic features
Solution Approach 1:
The system separates the heavy fixed nozzle from the lightweight movable flaps. The nozzle remains stationary and structurally simple, while the flaps—being much lighter and smaller—provide the necessary mobility for thrust direction control, thereby dramatically reducing the inertial value of the moving parts.
Solution Approach 2:
The invention changes the physical parameters of the movable component. Instead of moving the entire heavy nozzle assembly, only small, lightweight flaps at the exit are made movable. This parameter change (from large-mass nozzle to small-mass flaps) reduces inertial effects by an order of magnitude while preserving control authority.
3Ease of operation
If conventional TVC systems deflect the nozzle during operation, then attitude control is maintained, but structural engineering must account for complex loads, increasing design complexity
Solution Approach 1:
The system divides the structure into a fixed, heavily-braced nozzle and separate, lightly-braced flaps. The nozzle structure only needs to handle static combustion chamber pressure and thrust loads, while the flaps are designed to handle only the relatively small aerodynamic and actuator loads during deflection, significantly simplifying the overall structural engineering.
Solution Approach 2:
The invention extracts the attitude control function from the main nozzle structure. By placing the deflectable elements (flaps) outside the primary pressure containment structure, the nozzle can be engineered for pure pressure loads without the added complexity of accommodating dynamic deflection loads, while the flaps handle only the control-related loads.
4Power
If flaps are added around the exhaust nozzle exit section, then thrust boosting capability is achieved, but device complexity increases
Solution Approach 1:
The deflectable flaps serve multiple functions simultaneously: they provide attitude control by deflecting the exhaust flow, and they provide thrust boosting by extending the effective expansion ratio of the nozzle at high altitudes. This multi-functionality eliminates the need for separate systems, reducing overall complexity while achieving both objectives.
Solution Approach 2:
The invention merges the attitude control system and the thrust augmentation system into a single integrated flap mechanism. The same deflectable flaps that control thrust vectoring also serve as extension surfaces for area expansion ratio control, combining two functions into one structural solution and thereby reducing device complexity.
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 reduces costs and complexity, enhances dynamic performance by an order of magnitude, and mitigates impulse loads, while providing thrust and specific impulse boosting at high altitudes by optimizing nozzle expansion ratios.
Implementation Method 1
the flaps are so actuated as to deflect the supersonic gas flow exiting from the exit section of the nozzle
Implementation Method 2
the flaps are shaped so as to extend the divergent portion of the exhaust nozzle
Data Source
AI summary
An attitude control and thrust boosting system (100) for a space launcher is disclosed, wherein the space launcher is equipped with a rocket engine (303) provided with an exhaust nozzle. The exhaust nozzle comprises a divergent portion (302) so designed as to make a supersonic gas flow exit through an exit section defined by a given angle of divergence with respect to a longitudinal axis of the rocket engine. The attitude control and thrust boosting system (100) comprises flaps (110, 111, 112, 113) that are arranged around the exit section, are shaped so as to extend the divergent portion of the exhaust nozzle, are mechanically decoupled from said exhaust nozzle and can be actuated to take different angular positions with respect to the longitudinal axis of the rocket engine. Control means (130) are also provided to receive quantities indicative of an actual attitude of the space launcher and an ambient static pressure, and to make the flaps (110,111,112,113) take a neutral angular position where the flaps (110,111,112,113) are inclined, with respect to the longitudinal axis of the rocket engine, according to an inclination angle greater than, or equal to, the given angle of divergence, in order to control the neutral angular position taken by the flaps (110,111,112,113) according to the ambient static pressure and to make one or more flaps (110,111,112,113) take an angular position different than the neutral angular position according to the actual attitude of the space launcher and to a required attitude for said space launcher.