Ejector Thruster Configuration for VTOL Aircraft
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Solution Overview
Problem
VTOL aircraft face challenges in engine sizing and thrust balance, particularly during horizontal flight, where lift forces increase thrust requirements, leading to weight and efficiency issues.
Innovation Solution
The use of thrust augmentation systems, including ejectors/thrusters designed for 2-3 times conventional turbojet thrust, and a secondary ejector formed by the exhaust and a closed wing shroud, to enhance thrust and balance forces across multiple locations on the aircraft.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the aircraft uses conventional turbojet engines for horizontal flight, then the engine size and weight are reduced, but the thrust is insufficient for vertical take-off and landing
Solution Approach 1:
The propulsion system is divided into multiple independent ejector thrusters distributed at different locations on the aircraft (fore ejectors, aft ejectors, side ejectors). Each thruster provides a portion of the total thrust, allowing the aircraft to achieve vertical lift without requiring a single large heavy engine. The segmented thrust distribution also enables precise moment balancing around the center of mass.
Solution Approach 2:
The patent employs ejector thrusters that use compressed gas (pneumatic system) to generate thrust. The ejectors utilize the Venturi effect and pressure differentials to accelerate fluid flow and produce thrust forces. This pneumatic approach allows for high thrust-to-weight ratio compared to conventional turbojet engines, enabling vertical take-off capability with lighter propulsion systems.
2Stability of the object's composition
If the aircraft uses multiple thrust generating elements distributed around the aircraft, then moment balance is improved, but the device complexity increases
Solution Approach 1:
The thrust generation system is segmented into multiple independent ejector thrusters positioned at strategic locations (fore, aft, sides) around the aircraft. This segmentation allows each thruster to independently contribute to both vertical lift and moment balancing, simplifying the control architecture compared to a single complex vectored thrust system.
Solution Approach 2:
Each ejector thruster serves multiple functions: providing vertical lift during take-off and landing, generating forward thrust during horizontal flight, and creating moment forces for attitude control. This multi-functionality reduces the need for separate systems for each function, thereby managing overall device complexity.
3Power
If the aircraft is designed for vertical take-off with high thrust-to-weight ratio, then vertical lift capability is improved, but the engine weight becomes excessive for horizontal cruise flight
Solution Approach 1:
The ejector thrusters utilize compressed gas storage systems and pressure regulation mechanisms to generate high thrust forces. By storing compressed gas and releasing it through ejector nozzles, the system achieves high thrust-to-weight ratio without requiring heavy combustion engines, thus maintaining lightweight design for cruise flight while enabling vertical take-off capability.
Solution Approach 2:
The propulsion system dynamically adjusts thrust output by controlling the release rate and pressure of compressed gas in the ejector thrusters. During vertical take-off, maximum thrust is generated; during horizontal cruise, thrust is reduced to only what is needed for propulsion. This dynamic adjustment allows the same lightweight system to meet varying thrust requirements without carrying excessive weight.
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 efficient vertical take-off and landing, reduces engine size and weight, and enhances propulsive efficiency, enabling the aircraft to achieve level flight and longer-range missions with improved control and maneuverability.
Implementation Method 1
Each ejector is provided with compressed air as a propellant
Implementation Method 2
a secondary ejector formed by the exhaust and a closed wing shroud
Data Source
AI summary
A vehicle, includes a main body. A fluid generator is coupled to the main body and produces a fluid stream. At least one fore conduit and at least one tail conduit are fluidly coupled to the generator. First and second fore ejectors are fluidly coupled to the fore conduit, coupled to the main body and respectively coupled to a starboard side and port side of the vehicle. The fore ejectors respectively comprise an outlet structure out of which fluid flows. At least one tail ejector is fluidly coupled to the tail conduit. The tail ejector comprises an outlet structure out of which fluid flows. A primary airfoil element is coupled to the tail portion. A surface of the primary airfoil element is located directly downstream of the first and second fore ejectors such that the fluid from the first and second fore ejectors flows over the such surface.