Concentric Rocket-Electric Propulsion for Sabot-Free UAV Launch
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Solution Overview
Problem
Tube-launched unmanned aircraft vehicles (UAVs) face challenges with existing propulsion systems due to the addition of parts and launch debris from using a sabot, which complicates the launch process and increases system complexity.
Innovation Solution
A propulsion system incorporating a concentric arrangement of a rocket motor and an annular electric motor, where the rocket motor passes through a central opening in the electric motor, with a thermal isolation spacer and a foldable propeller system driven by the electric motor, allowing for efficient launch and thrust transition without a sabot.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sabot is used in the launcher, then the UAV can be launched, but additional parts and launch debris are added, increasing system complexity
Solution Approach 1:
The patent removes the sabot from the launch system entirely. The UAV is designed to be launched directly without a sabot, eliminating the source of launch debris and reducing the number of parts that need to be managed during launch and recovery operations.
Solution Approach 2:
The rocket motor and electric motor are combined in a concentric arrangement where the rocket motor passes through a central opening in the electric motor. This merging of propulsion systems eliminates the need for separate mounting structures and reduces overall system complexity.
2Force
If a sabot structure is added, then launch support is provided, but parts and debris are introduced, affecting operational reliability
Solution Approach 1:
The sabot is completely removed from the system. The UAV employs a direct launch mechanism where the airframe itself is designed to withstand launch forces without requiring an external sabot structure, thereby eliminating debris generation and improving operational reliability.
3Volume of moving object
If concentric motor arrangement is used, then space efficiency is improved, but thermal management becomes more challenging
Solution Approach 1:
The patent introduces a spacer between the rocket motor and electric motor that serves as a thermal barrier. This intermediary component provides thermal isolation to protect the electric motor from the high temperatures generated by the rocket motor exhaust, while still allowing the compact concentric arrangement to maintain space efficiency.
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
Enables efficient launch and thrust transition of UAVs without additional launch debris, reducing system complexity and enhancing operational reliability.
Implementation Method 1
the spacer provides thermal isolation between the rocket nozzle and the electric motor
Implementation Method 2
a rocket motor for rapid acceleration
Implementation Method 3
an annular electric motor that surrounds a part of the rocket motor
Data Source
AI summary
A propulsion system, such as for an aircraft, for instance an unmanned aircraft system (UAS), includes a rocket motor and an electric motor, with the rocket motor passing through a central opening in the electric motor. The electric motor may be a brushless outrunner electric motor, with a rotor of the electric motor radially outward of a stator of the electric motor. The electric motor may use part of the rocket motor, such as a rocket nozzle (to give a non-limiting example), and may be used to turn blades of a propeller, to propel the aircraft. The propeller blades may be foldable blades, hingedly coupled to a yoke. The blades may deploy after launch of the aircraft, such as from a launcher, for instance a launch tube.