Coanda Air Duct Thrust Generation for Low-Noise Drones
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Solution Overview
Problem
Conventional drones generate high noise levels and pose safety risks due to high-speed rotating propellers, which can cause accidents and disturb the environment.
Innovation Solution
A low-noise thrust generation apparatus using a pipe-shaped air guide and air duct that generates thrust through air injection, leveraging the Coanda effect and static pressure difference to produce twice the thrust of simple air injection, without high-speed rotating propellers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high-speed rotating propellers are used to generate thrust, then thrust generation capability is improved, but noise level increases and safety risks worsen
Solution Approach 1:
The patent extracts and eliminates the high-speed rotating propeller from the thrust generation system, replacing it with a stationary air injection system. The harmful rotating component is completely removed while thrust generation function is maintained through a different mechanism (air injection creating reaction force and utilizing Coanda effect), thereby resolving the noise and safety issues associated with propeller rotation.
Solution Approach 2:
The patent replaces the mechanical rotating propeller system with a fluid-based air injection system. Instead of using mechanical rotation to generate thrust, the system uses pressurized air injection through nozzles, leveraging fluid dynamics principles (reaction force, Coanda effect, induced flow) to generate thrust without moving mechanical parts, thus eliminating noise and safety hazards.
2Power
If propeller speed is increased to enhance thrust, then thrust output is improved, but aerodynamic noise increases
Solution Approach 1:
The patent substitutes the mechanical propeller rotation system with a stationary air injection system that uses pressurized gas flow. This replacement eliminates the aerodynamic noise generated by rotating blades while maintaining thrust output through reaction force from air ejection and Coanda effect, achieving quiet thrust generation.
Solution Approach 2:
The patent employs pneumatic principles by using compressed air as the working fluid to generate thrust. The air is injected through nozzles at high pressure, creating reaction force and utilizing the Coanda effect to adhere to the air duct surface and induce additional air flow, thereby generating thrust without mechanical moving parts and associated noise.
3Object-generated harmful factors
If simple air injection is used to avoid propellers, then safety and noise are improved, but thrust generation capability deteriorates
Solution Approach 1:
The patent introduces the Coanda effect as an intermediary mechanism to enhance thrust generation. The injected air adheres to the curved surface of the air duct (the intermediary structure), creating a low-pressure region that induces additional air flow from the surroundings. This intermediary mechanism amplifies the thrust effect without requiring high injection pressures or complex mechanical systems.
Solution Approach 2:
The patent utilizes the Coanda effect to add a dimensional aspect to thrust generation by having the air jet follow the curved surface of the air duct. This creates a three-dimensional flow pattern where the air adheres to the duct surface and induces radial inflow, effectively utilizing the duct geometry as an additional dimension for thrust enhancement rather than simple linear injection.
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 apparatus significantly reduces noise by 6 dB and enhances safety by eliminating high-speed propellers, allowing operation in populated areas and environments where propeller drones are unsafe.
Implementation Method 1
The air duct generates thrust through a reaction force caused by air injection
Implementation Method 2
generates additional thrust through a static pressure difference generated by the Coanda effect
Implementation Method 3
an air guide that has a second air flow path formed inside to be communicated with the first air flow path, and coupled with the air duct to transmit air introduced into the second air flow path to the first air flow path
Data Source
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AI summary
The present disclosure relates to a thrust generation apparatus for an unmanned aerial vehicle such as a drone, and more specifically, to a low-noise thrust generation apparatus which generates a similar level of thrust as a typical propeller unmanned aerial vehicle while generating less noise, and an unmanned aerial vehicle comprising same.