Counter-Rotating Blade Assembly for Compact Low-Frequency Underwater Sound
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Solution Overview
Problem
Existing underwater sound sources face challenges in achieving high-power, low-frequency sound emission with small size and efficient energy conversion, particularly in electroacoustic and hydrodynamic generation methods, and there is a lack of mature equipment for rotating-blade modulated acoustic sources.
Innovation Solution
A counter-rotating blade-type underwater low-frequency sound-emitting device with a counter-rotating blade assembly, driven by two assemblies and an oscillation converting mechanism, allowing independent adjustment of motion parameters to modulate low-frequency acoustic waves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If electroacoustic generation method is used to achieve high-power acoustic output, then acoustic power is improved, but device volume and weight increase, and energy conversion efficiency decreases
Solution Approach 1:
The patent replaces the electroacoustic transducer system with a hydrodynamic sound generation system using rotating blades. The blade-type sound emitting device generates acoustic waves through hydrodynamic interaction with water, eliminating the need for high-power electrical transducers and improving energy conversion efficiency from electrical to acoustic energy.
Solution Approach 2:
The patent employs dynamically rotating blades that can adjust their rotation speed and orientation to optimize acoustic wave generation. The rotating blade assembly creates time-varying hydrodynamic forces that efficiently generate acoustic waves, allowing dynamic control of acoustic power output while maintaining high energy conversion efficiency.
2Power
If electroacoustic generation method is used to achieve high-power acoustic output, then acoustic power is improved, but device volume and weight increase
Solution Approach 1:
The patent replaces heavy electroacoustic transducers and power amplification systems with a lightweight hydrodynamic blade system. The rotating blades generate acoustic power through mechanical interaction with water, eliminating the need for heavy electrical components and power supply systems.
Solution Approach 2:
The dynamically rotating blade assembly generates high acoustic power through efficient hydrodynamic interaction, replacing static or slowly varying electroacoustic systems. The dynamic rotation allows compact design while maintaining high power output capability.
3Power
If rotating-blade modulated acoustic source is developed, then low-frequency and high-power emission capability is improved, but device complexity increases
Solution Approach 1:
The patent divides the sound emitting device into modular components: a rotating blade assembly with multiple independent blades, a drive mechanism, and a housing. Each blade can be independently designed and adjusted, allowing complex acoustic functionality to be achieved through simple, repeatable modular units rather than a monolithic complex system.
Solution Approach 2:
The rotating blade assembly serves multiple functions: generating acoustic waves, modulating frequency through rotation speed control, and controlling direction through blade orientation. This multi-functionality reduces the need for separate components for each function, thereby reducing overall 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
The device achieves high-power, low-frequency sound emission with a simple structure, reliable function, and balanced torque, enabling efficient acoustic wave modulation with adjustable characteristics.
Implementation Method 1
The hydrodynamic source has a simple structure and high reliability, offering significant advantages in the low-frequency and high-power emission
Implementation Method 2
a counter-rotating blade assembly... comprising a main shaft, a primary blade assembly, a hub shaft, a secondary blade assembly... the counter-rotating conversion assembly is configured to reverse and transmit rotation of the primary blade assembly to the secondary blade assembly
Data Source
AI summary
A counter-rotating blade-type underwater low-frequency sound-emitting device includes a counter-rotating blade assembly, a first driving assembly, a second driving assembly and an oscillation converting assembly. The counter-rotating blade assembly includes a main shaft, a primary blade assembly mounted on the main shaft, a hub shaft sleeved on the main shaft, a secondary blade assembly mounted on the main shaft, and a counter-rotating conversion assembly. Two ends of the primary blade assembly are respectively connected to the hub shaft and the secondary blade assembly. The secondary blade assembly and the primary blade assembly have opposite rotating directions. The first driving assembly is configured to drive the hub shaft to rotate. The second driving assembly is configured to drive the main shaft to do linear reciprocation and convert it to periodic reciprocating oscillation of blades of the secondary blade assembly.