A dual-liquid cavity broadband transducer for deep water

Abstract

The present invention proposes a dual-liquid cavity broadband transducer for deep water, whose radiated sound field is formed by the superposition of the sound field generated by the resonance of the inner and outer liquid cavities and the radial resonance of the two circular ring transducers. This mixed excitation mode couples the two vibration modes to form broadband emission, and can radiate sound waves horizontally and omnidirectionally. Through the working mode of reverse-phase power drive, when the wavelength of the sound wave is much larger than the structural size of the transducer, when the high- and low-frequency overflow circular ring transducers radiate sound waves in reverse-phase radial vibration, the fluid in the inner liquid cavity is in a contraction phase, and the fluid in the outer liquid cavity is in an expansion phase. The transducer performs a similar breathing vibration, compensating and eliminating the inherent 180° phase difference between the high- and low-frequency liquid cavity vibrations, thereby improving the coupling between the sound radiation generated by the high- and low-frequency liquid cavity resonances and improving the electroacoustic conversion efficiency of the transducer.

Description

Technical Field

[0001] The invention relates to the field of transducers, and mainly relates to a double-liquid-cavity broadband transducer for deep water. Background Art

[0002] As the concept of "network-centric underwater warfare" becomes increasingly popular, the construction of an integrated underwater communication, detection, command and control, and navigation system with underwater information network as the core has received more and more attention. The multi-system underwater acoustic communication heterogeneous network is a new underwater information network that can be compatible with multiple communication systems, support diversified applications, and has the capabilities of interconnection of multiple network configurations, dynamic network self-organization, random access of mobile nodes, underwater auxiliary navigation and positioning, and on-demand expansion of network scale. As an "underwater mobile communication network", this network is a basic communication facility for constructing underwater reconnaissance and early warning systems, underwater attack and defense systems, and supporting new underwater early warning and attack and defense equipment such as distributed networked warning systems, underwater unmanned cluster systems, and underwater pre-positioned weapons. In order to ensure the interconnection of information between fixed nodes, mobile nodes, and fixed and mobile nodes in the network coverage area, the underwater acoustic communication transducers must be deployed on buoys or buoys on the seabed, in the sea, and on the sea surface. According to the channel conditions and application requirements of the underwater acoustic communication network nodes, the underwater acoustic communication transducer needs to have key performance such as broadband, high power, high hydrostatic pressure, high receiving sensitivity, and horizontal omnidirectionality. Taking into account the adaptability and efficiency requirements of the transducer, the size and weight of the transducer should be as small as possible, and the transmitting voltage response and source level per watt should be as high as possible, so as to reduce the power consumption and size and weight of each node.

[0003] At present, most underwater acoustic communication transducers with high receiving sensitivity, simple structure and easy use adopt circular transducers. Traditional single circular transducers work by coupling the liquid cavity of the piezoelectric circular ring with the radial vibration mode, and are mostly used in low-frequency underwater acoustic communications. However, the transducer has a single structure, only two resonant modes, and limited bandwidth expansion capability. In addition, the transducer design principle of multi-mode coupling can also be used to couple the vibration modes of the single circular transducer to achieve the widening of the transducer frequency band. For example, the radial vibration mode of the single circular transducer and the high-order radial vibration mode are coupled to achieve broadband transmission of the transducer. However, the transducer designed based on this principle cannot achieve horizontal non-directional operation.

[0004] The bandwidth of the ring transducer can also be widened by combining multiple rings, but currently all multi-ring transducers use a serial combination structure, such as the transducers invented by patents CN103400574A and CN106131744A, which are structures that string piezoelectric rings of the same or different radii together with metal rods, and then connect and tighten the metal rods through upper and lower cover plates, and finally seal the whole in a watertight manner. This type of multi-ring transducer can widen the bandwidth of the transducer within a certain range; however, this air-backed ring transducer cannot utilize the liquid cavity vibration mode of the ring transducer, and has limited bandwidth widening capability and limited deepwater working capability.

[0005] According to the channel conditions and application requirements of the underwater acoustic communication network nodes, the underwater acoustic communication transducer needs to have key performances such as broadband, high power, high hydrostatic pressure, high receiving sensitivity, and horizontal omnidirectionality. In addition, considering the adaptability and efficiency requirements of the transducer, the volume and weight of the transducer should be as small as possible, and the transmission voltage response and source level per watt should be as high as possible, so as to reduce the power consumption and size and weight of each node. However, it is difficult to take into account all the performance indicators of the transducer in theory. For example, increasing the volume displacement of the transducer can enable it to transmit at high power, and increasing the volume displacement of the transducer requires increasing the radiation area of ​​the transducer, which means that the size of the transducer and the volume of the active material need to be increased. Therefore, it is necessary to design a transducer with key performances such as small size, light weight, broadband, high power, high efficiency, high sensitivity, and horizontal omnidirectionality under the constraints of the transducer principle mechanism. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a dual-liquid cavity broadband transducer for deep water, which combines the advantages of the overflow ring and the ring transducer, and can radiate sound waves horizontally and omnidirectionally by liquid cavity vibration and ring radial vibration. This mixed excitation mode couples the two vibration modes to form broadband emission. Compared with other transducers of the same frequency, it is smaller in size, more powerful, wider in bandwidth, more resistant to hydrostatic pressure, and horizontally omnidirectional.

[0007] The purpose of the present invention is achieved through the following technical solutions: A deep-water dual-liquid-cavity broadband transducer, which uses two different-sized overflow ring transducers of high and low frequencies to nest inside and outside to form two different-sized dual-liquid-cavity structures, wherein the two overflow ring transducers use a separate cable structure, and the phase difference between the radial vibration of the ring itself and the vibration of the liquid cavity is changed by designing a suitable liquid cavity, transducer size, and driving the two overflow ring transducers in reverse phase, so that the radial vibration mode of the ring itself is coupled with the vibration mode of the dual liquid cavities to form broadband emission.

[0008] Furthermore, the low-frequency overflow ring transducer includes a low-frequency mosaic ceramic ring or a piezoelectric ceramic ring, and large flanges are arranged at both ends of the low-frequency mosaic ceramic ring or the piezoelectric ceramic ring formed by injection molding. The high-frequency overflow ring transducer includes a high-frequency mosaic ceramic ring or a piezoelectric ceramic ring, and small flanges are arranged at both ends of the high-frequency mosaic ceramic ring or the piezoelectric ceramic ring formed by injection molding; the small flange is connected to the large flange through a support rod, a decoupling connecting rod, and a screw to form a high-frequency liquid cavity in the high-frequency mosaic ceramic ring or the piezoelectric ceramic ring, and a low-frequency liquid cavity is formed between the high-frequency mosaic ceramic ring or the piezoelectric ceramic ring and the low-frequency mosaic ceramic ring or the piezoelectric ceramic ring.

[0009] Furthermore, the height center of the small ring of the high-frequency mosaic ceramic ring or the piezoelectric ceramic ring coincides with the height center of the large ring of the low-frequency mosaic ceramic ring or the piezoelectric ceramic ring, and the outer ring is higher than the inner ring, forming two high-frequency liquid cavities and low-frequency liquid cavities of different sizes inside and outside.

[0010] Furthermore, the small flange is connected to the large flange through three support rods, three decoupling connecting rods and screws, so that the overflow ring transducers of two different sizes, high and low frequencies, are concentrically nested inside and outside.

[0011] Furthermore, the overflow annular transducers of two different sizes, high and low frequencies, are sealed by polyurethane perfusion, forming a large perfusion layer and a small perfusion layer respectively.

[0012] The beneficial effects of the present invention are as follows: the present invention forms a dual liquid cavity structure by nesting two different sizes of overflow ring transducers of high and low frequency inside and outside, and changes the phase difference between the radial vibration of the ring itself and the vibration of the liquid cavity by designing a suitable liquid cavity and transducer size and driving the two overflow ring transducers in reverse phase, so that the radial vibration mode of the ring is coupled with the vibration mode of the dual liquid cavity to form broadband emission. This type of transducer has the advantages of small size, light weight, high power, high electroacoustic conversion efficiency, horizontal omnidirectionality, etc., and is suitable for constructing underwater communication infrastructure such as underwater reconnaissance and early warning systems and underwater attack and defense systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a cross-sectional view of a deep-water dual-liquid-cavity broadband transducer of the present invention.

[0014] Figure 2 It is a stereoscopic diagram of a deep-water dual-liquid-cavity broadband transducer according to the present invention.

[0015] Figure 3 The figure is a top view of a dual-liquid-cavity broadband transducer for deep water use according to the present invention.

[0016] Figure 4 The present invention provides sea trial data of the electroacoustic performance of a deep-water dual-liquid-cavity broadband transducer. DETAILED DESCRIPTION

[0017] The present invention will be described in detail below with reference to the accompanying drawings:

[0018] refer to Figures 1 to 3 The present invention discloses a dual-liquid-cavity broadband transducer for deep water, comprising: a low-frequency mosaic ceramic ring or a piezoelectric ceramic whole ring 1, a large perfusion layer 2, a large flange 3, a high-frequency mosaic ceramic ring or a piezoelectric ceramic whole ring 4, a small perfusion layer 5, a small flange 6, a support rod 7, a decoupling connecting rod 8, a screw 9, a cable head 10, a low-frequency liquid cavity 11, and a high-frequency liquid cavity 12.

[0019] The low-frequency overflow annular transducer comprises a low-frequency mosaic ceramic ring or piezoelectric ceramic ring 1, and large flanges 3 are arranged at both ends of the low-frequency mosaic ceramic ring or piezoelectric ceramic ring 1 formed by injection molding. The high-frequency overflow annular transducer comprises a high-frequency mosaic ceramic ring or piezoelectric ceramic ring 4, and small flanges 6 are arranged at both ends of the high-frequency mosaic ceramic ring or piezoelectric ceramic ring 4 formed by injection molding; the small flange 6 is connected to the large flange 3 through a support rod 7, a decoupling connecting rod 8, and a screw 9. The low-frequency mosaic ceramic ring or piezoelectric ceramic ring 1 and the high-frequency mosaic ceramic ring or piezoelectric ceramic ring 4 are nested to form two inner and outer double liquid cavity structures of different sizes, specifically: a high-frequency liquid cavity 12 is formed in the high-frequency mosaic ceramic ring or piezoelectric ceramic ring 4, and a low-frequency liquid cavity 11 is formed between the high-frequency mosaic ceramic ring or piezoelectric ceramic ring 4 and the low-frequency mosaic ceramic ring or piezoelectric ceramic ring 1.

[0020] The two mosaic ceramic rings are formed by coating the piezoelectric ceramic trapezoidal strips with epoxy adhesive. When installing the piezoelectric ceramic trapezoidal strips, attention should be paid to the direction, with the narrow side of the trapezoid facing inward and the wide side facing outward. After forming, the piezoelectric ceramic rings are gently tapped to make the piezoelectric ceramic rings as uniform and round as possible. After the cable head is welded in the mosaic ceramic ring, it is placed in the injection mold and sealed with polyurethane injection to form a large injection layer 2 and a small injection layer 5 respectively. The overflow mosaic ring transducer after injection molding is then clamped with a flange and fastened with screws. The small flange 6 is connected to the large flange 3 through three support rods 7, three decoupling connecting rods 8 and screws 9, so that the overflow ring transducers of two different sizes of high and low frequencies form concentric inner and outer nesting; the center of the small ring height direction of the high-frequency mosaic ceramic ring or piezoelectric ceramic ring 4 coincides with the center of the large ring height direction of the low-frequency mosaic ceramic ring or piezoelectric ceramic ring 1, and the outer ring is higher than the inner ring, forming two high-frequency liquid cavities 12 and low-frequency liquid cavities 11 of different sizes inside and outside. When working, this transducer forms two liquid cavities (high / low frequency liquid cavities) of different sizes inside and outside. By designing appropriate liquid cavities and transducer sizes and driving the two overflow ring transducers in reverse phase, the inherent 180° phase difference between the high and low frequency liquid cavity vibrations is compensated and eliminated. The coupling between the sound radiation generated by the high and low frequency liquid cavity resonances is improved, and the radial vibration mode of the ring is coupled with the vibration mode of the dual liquid cavities to form broadband emission, thereby improving the electroacoustic conversion efficiency of the transducer.

[0021] The present invention discloses a deep-water dual-liquid-cavity broadband transducer, which has an overall size of about Φ250mm*200mm and a weight of about 30kg. Figure 4 The present invention provides sea trial data of the electroacoustic performance of a dual-liquid-cavity broadband transducer for deep water use. In a wide frequency band from 4kHz to 13kHz, the transducer has a transmission voltage response level of not less than 134.6dB and a fluctuation of not more than ±3dB.

[0022] In the design of transducers, multimodal coupling is an effective design method to broaden the bandwidth of transducers. The main idea is to generate two or more modes of vibration in a vibration system or to adjust the interval between the fundamental frequency and high harmonics of a mode so that the response generated by the superposition does not produce discontinuities or excessively deep valleys, thereby achieving broadband emission.

[0023] The present invention designs an overflow ring transducer of two different sizes, high and low frequency, which are nested inside and outside to form a double liquid cavity structure, and overcomes the problem that the sound field generated by the resonance of the inner and outer liquid cavities formed when the inner and outer double rings vibrate radially has an inherent phase difference of 180°. By designing a suitable liquid cavity, transducer size, and the method of driving the two overflow ring transducers with reverse power, the four modes of the transducer, namely, low-frequency liquid cavity resonance, high-frequency liquid cavity resonance, low-frequency ring radial resonance, and high-frequency ring radial resonance, are effectively coupled, and the working bandwidth is further expanded compared with the traditional single ring transducer and multi-ring combination transducer. The present invention is a dual-liquid cavity broadband transducer for deep water, and its radiated sound field is formed by the superposition of the sound field generated by the resonance of the inner and outer liquid cavities and the radial resonance of the two ring transducers. This mixed excitation mode couples the two vibration modes to form broadband emission, and can radiate sound waves horizontally and omnidirectionally. Through the working mode of reverse power driving, when the wavelength of the sound wave is much larger than the structural size of the transducer, when the high and low frequency overflow ring transducers radiate sound waves in reverse radial vibration, the fluid in the inner liquid cavity is in the contraction phase and the fluid in the outer liquid cavity is in the expansion phase, the transducer performs a breathing-like vibration, compensating and eliminating the inherent 180° phase difference between the high and low frequency liquid cavity vibrations, thereby improving the coupling between the sound radiation generated by the high and low frequency liquid cavity resonances and improving the electroacoustic conversion efficiency of the transducer.

[0024] The dual-liquid-cavity broadband transducer for deep water of the present invention combines the key performances required for an underwater acoustic communication transducer, such as small size, light weight, broadband, high power, high efficiency, high sensitivity, and horizontal omnidirectionality.

[0025] It is understandable that, for those skilled in the art, any equivalent replacement or change to the technical solution and inventive concept of the present invention should fall within the protection scope of the claims attached to the present invention.

Claims

1. A dual-cavity broadband transducer for deep water, characterized in that: The overflow ring transducers of two different sizes, high and low frequency, are nested inside and outside to form a double liquid cavity structure of two different sizes. The two overflow ring transducers adopt a separate cable structure. By designing a suitable liquid cavity and transducer size and driving the two overflow ring transducers in reverse phase, the phase difference between the radial vibration of the ring itself and the liquid cavity vibration is changed, so that the radial vibration mode of the ring itself is coupled with the vibration mode of the double liquid cavity to form broadband emission. The low-frequency overflow annular transducer comprises a low-frequency mosaic ceramic ring or a piezoelectric ceramic ring (1), and large flanges (3) are arranged at both ends of the low-frequency mosaic ceramic ring or the piezoelectric ceramic ring (1) formed by injection molding. The high-frequency overflow annular transducer comprises a high-frequency mosaic ceramic ring or the piezoelectric ceramic ring (4), and small flanges (6) are arranged at both ends of the high-frequency mosaic ceramic ring or the piezoelectric ceramic ring (4) formed by injection molding. The small flange (6) is connected to the large flange (3) through a support rod (7), a decoupling connecting rod (8), and a screw (9), forming a high-frequency liquid cavity (12) in the high-frequency mosaic ceramic ring or the piezoelectric ceramic ring (4), and forming a low-frequency liquid cavity (11) between the high-frequency mosaic ceramic ring or the piezoelectric ceramic ring (4) and the low-frequency mosaic ceramic ring or the piezoelectric ceramic ring (1). The center of the small ring height direction of the high-frequency mosaic ceramic ring or piezoelectric ceramic ring (4) coincides with the center of the large ring height direction of the low-frequency mosaic ceramic ring or piezoelectric ceramic ring (1), and the outer ring is higher than the inner ring, forming two high-frequency liquid cavities (12) and low-frequency liquid cavities (11) of different sizes inside and outside.

2. The deep-water dual-liquid-cavity broadband transducer according to claim 1 is characterized in that: The small flange (6) is connected to the large flange (3) via three support rods (7), three decoupling connecting rods (8), and screws (9), so that the overflow annular transducers of two different sizes, high and low frequencies, are concentrically nested inside and outside.

3. The deep-water dual-liquid-cavity broadband transducer according to claim 1 is characterized in that: The overflow annular transducers of two different sizes, high and low frequencies, are sealed by polyurethane perfusion, respectively forming a large perfusion layer (2) and a small perfusion layer (5).

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