Distributed VTOL Ejector Layout for Thrust Balance and Cruise Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing VTOL aircraft face challenges in engine sizing and force balance due to varying thrust requirements during vertical take-off and horizontal flight, leading to inefficient weight distribution and propulsion efficiency.
Innovation Solution
The use of thrust augmenting ejectors and gas generators distributed across the aircraft, combined with shrouded thrusters and box wings, to achieve thrust augmentation ratios exceeding 2:1 to 3:1, allowing for efficient thrust distribution and improved maneuverability and propulsive efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a high thrust-to-weight ratio engine is used to achieve vertical take-off, then vertical lift capability is improved, but engine weight increases and becomes excessive for horizontal cruise flight
Solution Approach 1:
The propulsion system is divided into multiple independent thrust sources: a primary rear engine and multiple distributed ejector thrusters (fore ejectors, aft ejectors, side ejectors). This segmentation allows the primary engine to be sized for cruise efficiency while distributed thrusters provide supplemental thrust for VTOL operations, eliminating the need for a single oversized engine.
Solution Approach 2:
The system dynamically adjusts thrust distribution between the primary engine and distributed ejectors based on flight phase. During VTOL, all ejectors operate at high power; during cruise, the primary engine provides main thrust while ejectors can be reduced or shut down. This dynamic adaptation optimizes the thrust-to-weight ratio for each operational mode.
2Device complexity
If thrust is concentrated in one location (e.g., rear portion), then engine design is simplified, but aircraft balance and moment control become difficult
Solution Approach 1:
Thrust generation is segmented across multiple locations: fore ejectors at the front, aft ejectors at the rear, and side ejectors distributed laterally. This spatial segmentation of thrust sources enables precise moment control and aircraft balance during VTOL and transition phases, while each individual ejector remains relatively simple in design.
Solution Approach 2:
Different ejector locations provide different local thrust characteristics optimized for their specific functions. Fore ejectors control pitch and forward thrust, aft ejectors control yaw and rearward thrust, and side ejectors control roll and lateral positioning. This local optimization of thrust quality at each position achieves superior overall aircraft balance.
3Force
If thrust augmenting ejectors are distributed across the aircraft, then thrust distribution and balance are improved, but device complexity increases
Solution Approach 1:
Each ejector thruster is designed as a universal multi-functional unit that can provide thrust in multiple directions and serve multiple purposes (lift, forward thrust, balance control). This universality reduces the need for specialized components at each location, thereby limiting the increase in overall system complexity despite the distributed configuration.
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 configuration enables aircraft to achieve vertical take-off and landing with reduced runway length, maintain stable hover, and transition to horizontal flight with enhanced propulsive efficiency, achieving thrust levels exceeding the aircraft's weight and reducing specific fuel consumption.
Implementation Method 1
a gas generator (50) producing a fluid stream
Implementation Method 2
thrust augmenting ejectors and gas generators distributed across the aircraft, combined with shrouded thrusters and box wings, to achieve thrust augmentation ratios exceeding 2:1 to 3:1
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 tad conduit is fluidly coupled to the generator. First and second fore ejectors are 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 includes a closed wing having a leading edge and a trailing edge. The leading and trailing edges of the closed wing define an interior region. The at least one propulsion device is at least partially disposed within the interior region.