Ultrasonic cavitation structure and phased array ultrasonic device thereof

Abstract

The invention relates to the field of ultrasonic equipment, and particularly discloses an ultrasonic cavitation structure and a phased array ultrasonic device.The ultrasonic cavitation structure comprises a cavitation cavity, the inner wall of the cavitation cavity is provided with a periodic micro-nano groove array, the depth of grooves is 1 / 4-1 / 2 of the length of ultrasonic waves, and the distance between the grooves is 1-2 times of the wavelength; the multi-mode transducer group is arranged around the outer wall of the cavitation cavity and comprises at least three groups of piezoelectric ceramic units with different working frequencies, and the frequency range is 20 kHz to 10 MHz; the vortex generator is arranged at the bottom of the cavitation cavity, and an included angle of 30-60 degrees is formed between the rotating direction of a spiral diversion trench of the vortex generator and the arrangement direction of the groove array; through the cavitation cavity structure, the sound field distribution is optimized, so that the generation and collapse process of cavitation bubbles is more efficient; due to the synergistic effect of the multi-mode transduction system, the more uniform and more stable cavitation effect is achieved; and the vortex generating device is introduced, so that the action time of the bubbles is effectively prolonged, and the energy utilization efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the field of ultrasonic devices, and more particularly to an ultrasonic cavitation structure and a phased array ultrasonic device thereof. Background Art

[0002] Ultrasonic cavitation technology is a physical process that utilizes ultrasonic waves to generate periodic pressure changes in a liquid, inducing the generation, growth, and collapse of cavitation bubbles. This technology is based on the acoustic cavitation effect. When the negative pressure phase of the sound wave exceeds the tensile strength of the liquid, cavities are formed, and when the positive pressure phase occurs, the bubbles collapse violently, instantaneously generating extremely high temperatures, high pressures, and microjets.

[0003] This phenomenon has important application values in fields such as industrial cleaning, nanomaterial synthesis, and biomedical treatment. The core lies in achieving energy transfer and material transformation by controlling the dynamic behavior of cavitation bubbles.

[0004] Traditional ultrasonic cavitation structures use smooth-walled cavitation chambers, where the sound wave reflection is irregular, resulting in random cavitation bubble nucleation, especially concentrated in a few hot spots. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides an ultrasonic cavitation structure to address the problem in the prior art that the ultrasonic cavitation structure uses a smooth-walled cavitation chamber, resulting in irregular sound wave reflection, random cavitation bubble nucleation, especially concentrated in a few hot spots.

[0006] An ultrasonic cavitation structure, comprising:

[0007] A cavitation chamber, the inner wall of which is provided with a periodic micro-nano groove array, the depth of the groove being 1 / 4 - 1 / 2 of the ultrasonic wavelength, and the groove pitch being 1 - 2 times the wavelength;

[0008] A multi-modal transducer group, arranged around the outer wall of the cavitation chamber, including at least 3 piezoelectric ceramic units with different operating frequencies, and the frequency range is 20 kHz - 10 MHz;

[0009] An eddy current generator, provided at the bottom of the cavitation chamber, and the spiral flow guide groove thereof has a helix angle of 30° - 60° with the arrangement direction of the groove array.

[0010] Preferably, the cross-section of the micro-nano groove array is an asymmetric trapezoid, the inclination angle α is 15° - 45°, and the surface of the groove is coated with a hydrophobic coating, and the contact angle > 150°.

[0011] Preferably, the piezoelectric ceramic units of the multi-modal transducer group are arranged in a fan shape, and an acoustic isolation layer is provided between adjacent units, and the material of the isolation layer is a composite material of silicone rubber and tungsten carbide powder.

[0012] A phased array ultrasonic device, comprising the ultrasonic cavitation structure as described above, further comprising:

[0013] A phase controller that adjusts the excitation timing of each piezoelectric ceramic unit through a dynamic delay algorithm, with a delay step of 5 - 50 ns;

[0014] A cavitation monitoring module, including a high - frequency impedance analyzer and a high - speed camera, which provides real - time feedback on the cavitation intensity distribution.

[0015] Preferably, the phase controller is integrated with an adaptive feedback system that dynamically adjusts the excitation parameters according to the data of the cavitation monitoring module to achieve three - dimensional focusing of the cavitation area, with a focusing accuracy < 0.1 mm.

[0016] Preferably, it further includes a multi - physical - field coupling module that synchronously applies a pulsed electric field and a magnetic field, with an electric field strength of 1 - 10 kV / cm and a magnetic field strength of 0.1 - 1 T.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] Through the cavitation cavity structure, the sound field distribution is optimized, making the generation and collapse processes of cavitation bubbles more efficient; the synergistic effect of the multi - modal transducer system achieves a more uniform and stable cavitation effect; and the introduction of the vortex - generating device effectively prolongs the bubble action time and improves the energy utilization efficiency;

[0019] Through the phase control technology, precise focusing of the cavitation area can be achieved; the intelligent feedback system monitors and adjusts the working parameters in real time to ensure the stability and controllability of the cavitation effect; the multi - physical - field coupling effect further improves the controllability of the cavitation process. Brief Description of the Drawings

[0020] Figure 1 It is the architecture diagram of the ultrasonic cavitation structure of the present invention;

[0021] Figure 2 It is the architecture diagram of the phased - array ultrasonic device of the present invention. Detailed Embodiments

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] As Figure 1 shown:

[0024] Embodiment 1: The present invention provides an ultrasonic cavitation structure, including:

[0025] A cavitation cavity, with a periodic micro-nano groove array provided on its inner wall, the depth of the grooves being 1 / 4 - 1 / 2 of the ultrasonic wavelength, and the groove spacing being 1 - 2 times the wavelength;

[0026] A multi-modal transducer group, arranged around the outer wall of the cavitation cavity, comprising at least 3 piezoelectric ceramic units with different operating frequencies, and the frequency range is 20 kHz - 10 MHz;

[0027] An eddy current generator, provided at the bottom of the cavitation cavity, and the spiral flow guiding groove of which has a spiral direction forming an angle of 30° - 60° with the arrangement direction of the groove array.

[0028] As can be seen from the above, during operation, the cavitation cavity, the multi-modal transducer group and the eddy current generator cooperate to form an efficient cavitation effect:

[0029] Cavitation cavity: Induce ultrasonic wave reflection and interference through the periodic micro-nano groove array to form local high-pressure / low-pressure areas, and promote the nucleation and collapse of cavitation bubbles;

[0030] Multi-modal transducer group: Excite multi-frequency ultrasonic waves by at least 3 piezoelectric ceramic units with different frequencies, covering wide-band resonance modes, and enhance the cavitation intensity and uniformity;

[0031] Eddy current generator: The spiral flow guiding groove forms an angle of 30° - 60° with the groove array, drives the fluid to form a spiral eddy current, prolongs the bubble residence time and improves the cavitation energy utilization rate.

[0032] Embodiment 2: This embodiment is basically the same as the previous embodiment, the difference is that it further includes that the cross-section of the micro-nano groove array is an asymmetric trapezoid, the inclination angle α is 15° - 45°, and the groove surface is coated with a hydrophobic coating, and the contact angle > 150°.

[0033] Specifically, the piezoelectric ceramic units of the multi-modal transducer group are arranged in a fan shape, and an acoustic isolation layer is provided between adjacent units, and the isolation layer material is a composite material of silicone rubber and tungsten carbide powder.

[0034] As can be seen from the above, the asymmetric trapezoidal cross-section guides the fluid to generate a directional shear flow through geometric asymmetry, and enhances the peeling and migration of cavitation bubbles;

[0035] The hydrophobic coating significantly reduces the attachment resistance of cavitation bubbles, promotes the rapid collapse of bubbles and reduces energy loss;

[0036] The piezoelectric ceramic units arranged in a fan shape excite a multi-directional sound field through a phase difference, covering a wider cavitation area;

[0037] The silicone rubber / tungsten carbide composite material isolation layer suppresses acoustic crosstalk and ensures the independent regulation accuracy of each unit frequency;

[0038] The spiral flow guide groove and the asymmetric groove cooperate to form a three-dimensional spiral vortex, extend the movement path of the bubbles and improve the energy coupling efficiency.

[0039] As Figure 2 shown:

[0040] Example 3: A phased array ultrasonic device, including the above ultrasonic cavitation structure, further includes:

[0041] A phase controller that adjusts the excitation timing of each piezoelectric ceramic unit through a dynamic delay algorithm, and the delay step is 5 - 50 ns;

[0042] A cavitation monitoring module, including a high-frequency impedance analyzer and a high-speed camera, which provides real-time feedback on the cavitation intensity distribution.

[0043] Specifically, the phase controller is integrated with an adaptive feedback system that dynamically adjusts the excitation parameters according to the data of the cavitation monitoring module to achieve three-dimensional focusing of the cavitation area, and the focusing accuracy < 0.1 mm.

[0044] Specifically, it further includes a multi-physical field coupling module that synchronously applies a pulsed electric field and a magnetic field, with an electric field intensity of 1 - 10 kV / cm and a magnetic field intensity of 0.1 - 1 T.

[0045] As can be seen from the above, under the control of the phase controller, the multi-modal transducer group generates an interference sound field through a dynamic delay algorithm, making the ultrasonic phase differences of each piezoelectric ceramic unit accurately match to achieve three-dimensional focusing of the cavitation area;

[0046] The adaptive feedback system dynamically adjusts the excitation frequency and timing according to the real-time data of the cavitation monitoring module to optimize the cavitation intensity distribution;

[0047] The multi-physical field coupling module synchronously applies a pulsed electric field and a magnetic field, and drives the directional migration of cavitation bubbles through the Lorentz force and dielectrophoresis effect, and enhances the energy release efficiency when the bubbles collapse;

[0048] The orthogonal superposition of the electric field and the magnetic field further regulates the fluid motion to form a composite enhancement effect of vortex and acoustic streaming;

[0049] The cavitation monitoring module captures the changes in the electrical characteristics of the bubble group through a high-frequency impedance analyzer, and combines the high-speed camera to visually record the dynamic behavior of the cavitation bubbles to form a closed-loop feedback chain;

[0050] The monitoring data is transmitted to the phase controller in real time to achieve adaptive tracking and focusing of the cavitation area.

[0051] Example 4: Micro-nano groove array and sound field optimization

[0052] Structural parameters:

[0053] The diameter of the cavitation cavity is 50 mm, and a trapezoidal groove array with an inner wall processing depth of 50 μm (1 / 4 of the ultrasonic wavelength corresponding to 1 MHz) and a spacing of 200 μm (2 times the wavelength) is processed.

[0054] The inclination angle of the groove is 30°, and a fluorosilane hydrophobic coating (contact angle 152°) is sprayed on the surface.

[0055] Working process:

[0056] Acoustic field regulation: When 1 MHz ultrasonic waves enter the cavity, the groove array forms a periodic standing wave field through the Bragg scattering effect, generating local pressure extreme points (±0.8 MPa) at the groove edges, which promotes cavitation bubble nucleation.

[0057] Hydrophobic effect: The hydrophobic coating reduces the bubble adhesion energy to 0.05 mJ / m 2 , shortening the bubble collapse time by 40% and increasing the micro-jet velocity to 120 m / s (compared with only 80 m / s for the smooth wall surface).

[0058] Effect verification: The high-speed camera shows that the distribution density of cavitation bubbles increases by 3 times, and there is no phenomenon of local hot spot concentration.

[0059] Example 5: Cooperative work of multimodal transducers

[0060] Hardware configuration:

[0061] Three groups of piezoelectric ceramic elements: low-frequency group (20 kHz, for large-volume cavitation), intermediate-frequency group (1 MHz, main control frequency), high-frequency group (10 MHz, for microbubble fine control).

[0062] Fan-shaped arrangement (central angle 90°), and the isolation layer is silicone rubber + 40% tungsten carbide (acoustic impedance 8.5 MRayl).

[0063] Control logic:

[0064] Phase control: Through a 5 ns step delay algorithm, the sound waves generated by the three groups of transducers form constructive interference in the target area (coordinates x = 10 mm, y = 5 mm).

[0065] Band coupling: The 20 kHz beam drives the macroscopic flow field, the 10 MHz beam precisely excites the microbubbles at the target sites, and the 1 MHz wave maintains steady-state cavitation.

[0066] Measured data: The volume of the cavitation area expands by 2.2 times, and the standard deviation of the energy density decreases from ±25% to ±8%.

[0067] Example 6: Enhancement of multi-physical field coupling

[0068] System integration:

[0069] Pulsed electric field: 5 kV / cm, pulse width 100 μs; magnetic field: 0.5 T Helmholtz coil.

[0070] The helix angle of the eddy current generator is 45°, and the pitch of the flow guiding groove is 3 mm.

[0071] Synergistic mechanism:

[0072] Electromagnetic-acoustic coupling: The Lorentz force drives the electrolyte to form a vortex flow, extending the movement path of the cavitation bubbles by 60%.

[0073] Dynamic focusing: According to the feedback of the impedance analyzer (when the resonance frequency shift Δf > 5 kHz), the phase of the transducer is adaptively adjusted to achieve a focusing accuracy of 0.08 mm.

[0074] Effect comparison: In the nanoparticle synthesis experiment, the CV value of the particle size distribution decreased from 18% to 7%, and the reaction efficiency increased by 90%.

[0075] Table for comparative analysis of examples

[0076]

[0077] All standard parts used in the present invention can be purchased from the market. Special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part all adopt conventional means such as bolts, rivets, and welding that are mature in the prior art. The machines, parts, and equipment all adopt conventional models in the prior art. In addition, the circuit connection adopts the conventional connection method in the prior art, which will not be elaborated here. The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0078] In the description of the present invention, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. The meaning of "plurality" is two or more unless otherwise specifically defined.

[0079] In the present invention, unless otherwise clearly defined and limited, the terms "mounted", "connected", "connected to", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0080] In the present invention, unless otherwise clearly defined or limited, a first feature being "on" or "under" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "over" and "on top of" a second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. A first feature being "under", "beneath" and "underneath" a second feature may mean that the first feature is directly below or obliquely below the second feature, or merely indicates that the horizontal height of the first feature is less than that of the second feature.

[0081] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0082] In the drawings of the disclosed embodiments of the present invention, only the structures related to the disclosed embodiments are involved, and other structures can refer to the general design. Without conflict, the same embodiment and different embodiments of the present invention can be combined with each other.

[0083] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An ultrasonic cavitation structure, characterized in that, Comprising: A cavitation cavity, the inner wall of which is provided with a periodic micro-nano groove array, the depth of the groove being 1 / 4 - 1 / 2 of the ultrasonic wavelength, and the groove spacing being 1 - 2 times the wavelength; A multi-modal transducer group arranged around the outer wall of the cavitation cavity, comprising at least 3 piezoelectric ceramic units with different operating frequencies, and the frequency range is 20 kHz - 10 MHz; An eddy current generator is provided at the bottom of the cavitation cavity, and the spiral flow guide groove of which has an included angle of 30° - 60° with the arrangement direction of the groove array.

2. The ultrasonic cavitation structure according to claim 1, wherein, The cross-section of the micro-nano groove array is an asymmetric trapezoid, the inclination angle α is 15° - 45°, and the surface of the groove is coated with a hydrophobic coating, and the contact angle > 150°.

3. The ultrasonic cavitation structure according to claim 1, characterized in that The piezoelectric ceramic units of the multi-modal transducer group are arranged in a fan shape, and an acoustic isolation layer is provided between adjacent units, and the material of the isolation layer is a composite material of silicone rubber and tungsten carbide powder.

4. A phased array ultrasonic device, characterized in that, Comprising the ultrasonic cavitation structure according to any one of claims 1 - 3, further comprising: A phase controller that adjusts the excitation timing of each piezoelectric ceramic unit through a dynamic delay algorithm, and the delay step is 5 - 50 ns; A cavitation monitoring module, including a high-frequency impedance analyzer and a high-speed camera, which can provide real-time feedback on the cavitation intensity distribution.

5. The phased array ultrasonic device according to claim 4, wherein, The phase controller is integrated with an adaptive feedback system, which dynamically adjusts the excitation parameters according to the data of the cavitation monitoring module to achieve three-dimensional focusing of the cavitation area, and the focusing accuracy < 0.1 mm.

6. The phased array ultrasonic device according to claim 4, characterized in that, It further includes a multi-physical field coupling module that synchronously applies a pulsed electric field and a magnetic field, the electric field intensity is 1 - 10 kV / cm, and the magnetic field intensity is 0.1 - 1 T.

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