Pulsed Thermal Acoustic Generator Using Porous Metal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional thermoacoustic wave generators face difficulties in producing high-frequency ultrasonic waves due to size constraints and efficiency losses, making it nearly impossible to generate waves above 3 kHz, and previous solutions like thin metal plate membrane structures suffer from low frequency efficiency and large light interrupter size issues.
Innovation Solution
A high-frequency acoustic wave generator using a pulsed thermal radiation beam is designed with a focusing tube, light interrupter, and a porous material with aluminum wires, where the pulse beam causes rapid thermal expansion and contraction of air in an air column, enhancing efficiency and productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional thermoacoustic wave generators use a porous stack in a transparent tube with solar light heating, then they can generate low-frequency acoustic waves (up to 3 kHz), but they cannot generate high-frequency ultrasonic waves (18 kHz or more) due to the inverse relationship between tube size and frequency
Solution Approach 1:
The patent uses a porous metal plate structure instead of a conventional porous stack in a transparent tube. The porous metal plate with its three-dimensional network structure allows direct thermal radiation heating of the metal wires, which then rapidly expand and contract to generate ultrasonic waves. This eliminates the need for a large transparent tube while achieving high-frequency generation.
Solution Approach 2:
The patent replaces the conventional solar light heating mechanism with a pulsed thermal radiation beam system. A light interrupter modulates a thermal radiation beam to create pulsed heating of the porous metal plate, which generates ultrasonic waves through rapid thermal expansion and contraction of the metal wires. This substitution enables high-frequency generation without requiring large tube dimensions.
2Speed
If a thin metal plate membrane structure is used to generate high-frequency waves, then frequency generation is improved, but the efficiency is low because solar light is lost in air before reaching the membrane, and the light interrupter size must be greatly increased
Solution Approach 1:
The patent employs a porous metal plate structure that directly absorbs thermal radiation energy. The three-dimensional network of metal wires provides a large surface area for absorbing thermal radiation, eliminating the energy loss that occurs when light travels through air to reach a thin metal plate membrane. The porous structure allows direct heating of the metal wires, improving energy efficiency.
Solution Approach 2:
The patent introduces a thermal radiation beam as an intermediary energy carrier. Instead of using solar light that is lost in air transmission, the thermal radiation beam directly heats the porous metal plate. The light interrupter modulates this thermal radiation beam to create pulsed heating, efficiently transferring energy to the metal wires for ultrasonic wave generation.
3Speed
If a thin metal plate membrane structure is used for high-frequency generation, then frequency is improved, but the light interrupter size must be greatly increased depending on the size of the thin metal plate, making commercialization difficult
Solution Approach 1:
The patent uses a porous metal plate with a three-dimensional network structure that can be made in compact sizes. The porous structure provides sufficient surface area for thermal radiation absorption in a small volume, eliminating the need for large light interrupters. The metal wires in the porous structure can be efficiently heated by a compact pulsed thermal radiation beam system.
Solution Approach 2:
The patent changes the physical state and arrangement of the metal structure from a thin plate membrane to a porous three-dimensional network. This parameter change allows the structure to absorb thermal radiation more efficiently in a compact form factor, enabling high-frequency generation with a smaller light interrupter size that is suitable for commercialization.
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 generator effectively produces high-frequency ultrasonic waves with improved efficiency and productivity, suitable for industrial applications like sterilization and washing, by maximizing thermal responsiveness and minimizing transmission losses.
Implementation Method 1
thin wires of the porous material repeatedly rapidly thermally-expand and contract, whereby air in the space between the wires is momentarily heated and cooled
Implementation Method 2
a pulsed thermal radiation beam that is configured such that when a pulse beam formed by a light interrupter is directly radiated onto a porous material
Implementation Method 3
a focusing tube focusing solar light collected by a solar tracking reflector to form high-density light and emitting the focused solar light
Implementation Method 4
air in the space between the wires is momentarily heated and cooled
Implementation Method 5
the expansion and contraction of air is directly transmitted to an air column formed just adjacent to the porous material
Data Source
AI summary
Disclosed herein is a high-efficiency acoustic wave generator using a pulsed thermal radiation beam. The generator is configured such that when a pulse beam formed by a light interrupter is directly radiated onto a porous material having a woven net or steel scrubber shape, thin wires of the porous material repeatedly rapidly thermally-expand and contract, whereby air in the space between the wires is momentarily heated and cooled, and the expansion and contraction of air is directly transmitted to an air column formed just adjacent to the porous material. By virtue of the above structure, the efficiency of the generator is markedly improved compared to the conventional technique, and the productivity is also greatly enhanced.