Method for evaluating the bubble performance of a marine acoustic device
Patent Information
- Application Number
- CN202611125064.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-28
- Publication Date
- 2026-10-30
AI Technical Summary
然而，船舶声学设备是船舶进行水下探测、海底地形测绘、导航作业的核心装备，缺乏对船舶声学设备进行系统化、定量化的评估手段，不仅制约船载声学设备性能的进一步提升，还影响相关船舶总体设计中声学设备的选型、布置及外形优化工作；因此，亟需一种能够精准评估船舶声学设备气泡性能的方法，以实现对船舶声学设备的气泡性能进行定性与定量分析
本发明结构紧凑、合理，操作方便，通过设置四个步骤，能够系统性分析船舶航行时船体表面的特征流线分布与压力梯度变化，对声学设备所处环境的气泡风险进行定性与定量相结合的深入分析，为船舶设计阶段的声学设备选型与安装位置优化，提供更为科学、客观的决策依据和参考。
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Figure CN123013283A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of bubble performance evaluation technology for marine acoustic equipment, and in particular to a method for evaluating the bubble performance of marine acoustic equipment. Background Technology
[0002] Bubbles in the ship's acoustic environment mainly originate from two aspects. First, air generated by the breaking of the bow wave enters the water, forming a dense bubble cloud. These bubbles flow with the water flow along the bottom of the hull to the rear. If they enter the installation location of the acoustic transducer, they will cause obstruction. Second, when the ship is sailing at high speed, the local pressure on the surface of the transducer array or near the hull protrusions drops below the vaporization pressure, thereby generating cavitation and causing acoustic noise.
[0003] During ship navigation, bubbles in the ship's acoustic environment can interfere with ship acoustic equipment (such as sonar, multibeam echo sounders, ADCP, etc.): the flow of bubble clusters around the hull can interfere with the transmission and reception of acoustic signals by acoustic equipment. Especially at high speeds or in rough seas, bubbles are a key physical factor affecting the performance of acoustic equipment, usually manifesting as signal interruption, depth sounding distortion, or a significant reduction in range. In addition, the downward sweeping phenomenon of bubbles is particularly critical for exploration vessels, which can greatly reduce the working efficiency, working depth, and working bandwidth of acoustic equipment.
[0004] In existing technologies, the interference of air bubbles on marine acoustic equipment is typically addressed through empirical judgment and limited tank model tests, using methods such as adding fairings and optimizing hull lines. However, marine acoustic equipment is core equipment for underwater exploration, seabed topography mapping, and navigation operations. The lack of systematic and quantitative evaluation methods for marine acoustic equipment not only restricts further improvements in its performance but also affects the selection, layout, and shape optimization of acoustic equipment in the overall design of related vessels. Therefore, there is an urgent need for a method that can accurately evaluate the bubble performance of marine acoustic equipment, enabling qualitative and quantitative analysis of its bubble performance. Summary of the Invention
[0005] To address the shortcomings of existing production technologies, this applicant provides a structurally sound method for evaluating the bubble performance of marine acoustic equipment. By extracting characteristic streamlines and performing pressure gradient analysis on these streamlines, qualitative and quantitative analysis of the bubble performance of marine acoustic equipment can be achieved, enabling accurate evaluation of the bubble performance of marine acoustic equipment.
[0006] The technical solution adopted in this invention is as follows: A method for evaluating the bubble performance of marine acoustic equipment includes the following steps: S1. Perform detailed simulation of the flow field of the ship at different speeds, divide the ship into local densification zones, and during the simulation, densify the local densification zones to capture the flow field gradient within the local densification zones; S2. Define a key area for feature extraction on the ship, arrange seed point groups in the key area for feature extraction, extract feature streamlines passing through the seed point groups, and conduct a preliminary evaluation of the bubble performance of the ship's acoustic equipment by tracking the coverage of the feature streamlines. S3. Extract the three-dimensional spatial data of each discrete point on the feature streamline, perform pressure gradient analysis on the feature streamline, and map the three-dimensional spatial data into a one-dimensional arc length function to obtain the one-dimensional pressure coefficient distribution curve along the feature streamline path. S4. Based on the one-dimensional pressure coefficient distribution curve and the criteria for evaluating the bubble performance of acoustic equipment, the bubble performance of the ship's acoustic equipment is evaluated in the final assessment.
[0007] As a further improvement to the above technical solution: In S1, the RANS method is used to solve the global flow field of the ship, the VOF method is used to handle the wave-making of the free surface, and the DBFI method is used to handle the six-degree-of-freedom motion of the ship, thereby achieving a detailed simulation of the flow field of the ship at different speeds.
[0008] In S1, the local encryption zone includes the bow wave-making area and the bottom boundary layer.
[0009] In S2, the key areas for feature extraction include the bow wave breaking area and the surface area of the acoustic equipment transducer mounting window.
[0010] In S2, when conducting a preliminary assessment of the bubble performance of the ship's acoustic equipment, it is assessed whether the characteristic streamlines of the wave breaking area at the bow pass through the acoustic equipment transducer mounting window, and whether the characteristic streamlines of the surface area of the acoustic equipment transducer mounting window are smooth.
[0011] In S3, the three-dimensional spatial data of each discrete point on the feature streamline includes coordinates. velocity components and dimensionless pressure coefficient .
[0012] In S3, the expression for the one-dimensional pressure coefficient distribution curve is as follows:
[0013] This represents the arc length of the one-dimensional pressure coefficient distribution curve; This represents the x-axis coordinate of the corresponding discrete point; This represents the ordinate of the corresponding discrete point; Represents the vertical axis coordinates of the corresponding discrete points; This represents the dimensionless pressure coefficient. This represents the pressure at the corresponding discrete point; Represents the hydrostatic pressure at infinity; Indicates fluid density; This indicates the incoming flow velocity.
[0014] Based on the one-dimensional pressure coefficient distribution curve, the comprehensive index function is obtained. Quantitative analysis of bubble performance in marine acoustic equipment, comprehensive index function. The expression is as follows:
[0015] In the formula, Indicates the endpoint of the assessment control area on the streamline; Indicates the starting point of the assessment control area on the streamline; Represents the weighting function; This represents the dimensionless pressure coefficient. This represents the arc length of the one-dimensional pressure coefficient distribution curve.
[0016] The criteria for evaluating the bubble performance of acoustic devices include: When the coverage of the feature streamlines shows that all feature streamlines bypass the key area for feature extraction, the risk level is determined to be safe. When the coverage of the feature streamlines shows that some feature streamlines pass through the edge of the key area for feature extraction, the risk level is determined to be low risk. When the coverage of the feature streamlines shows that all or part of the feature streamlines cover the key area for feature extraction, the risk level is determined to be medium risk or high risk. When the coverage area of the characteristic streamlines shows that all or part of the characteristic streamlines enter the return flow zone, or when the coverage area of the characteristic streamlines shows that all or part of the characteristic streamlines enter the separation zone, the risk level is determined to be extreme risk.
[0017] When the risk level is determined to be medium or high, according to the one-dimensional pressure coefficient distribution curve, if the flow field section through which the feature streamlines covering the key area of feature extraction pass is in the isobaric zone, the risk level is determined to be medium. If the flow field section traversed by the feature streamline covering the key area of feature extraction is in the growth region, the risk level is determined to be high risk.
[0018] The beneficial effects of this invention are as follows: This invention features a compact and rational structure and is easy to operate. By setting up four steps, it can systematically analyze the characteristic streamline distribution and pressure gradient changes on the surface of a ship during navigation, and conduct an in-depth qualitative and quantitative analysis of the bubble risk in the environment where acoustic equipment is located. This provides a more scientific and objective decision-making basis and reference for the selection and optimization of acoustic equipment installation location during the ship design stage.
[0019] This invention, through steps of high-precision flow field numerical simulation, feature streamline extraction, and pressure gradient analysis, can comprehensively understand the distribution and motion patterns of bubbles near acoustic equipment during ship navigation, providing a systematic and quantitative means for evaluating the bubble performance of ship acoustic equipment. Compared with existing technologies, the evaluation method of this invention no longer relies on empirical judgment and limited water tank model tests, but instead provides a more reliable basis for the layout and shape optimization of acoustic equipment during ship design through scientific numerical analysis and evaluation criteria, significantly reducing ship design costs and risks. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of ship simulation in this invention.
[0021] Figure 2 This is a schematic diagram showing the installation position of the acoustic transducer of the present invention at the bottom of the ship.
[0022] Figure 3 This is a schematic diagram of the characteristic streamlines of the ship in this invention. Figure 1 .
[0023] Figure 4 This is a schematic diagram of the characteristic streamlines of the ship in this invention. Figure 2 .
[0024] Figure 5 This is a schematic diagram of the one-dimensional pressure coefficient distribution curve in this invention. Detailed Implementation
[0025] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.
[0026] To address the issue of bubble clusters affecting the vicinity of acoustic equipment during ship navigation, this embodiment proposes a method for evaluating the bubble performance of ship acoustic equipment, such as... Figures 1-5 As shown, it includes the following steps: S1. Perform detailed simulation of the flow field of the ship at different speeds, and divide the ship into local densification zones, which include the wave-making region at the bow and the boundary layer at the bottom. During the simulation, the local densification zone is locally densified to capture the flow field gradient within the local densification zone. Specifically, based on CFD software, the RANS method (Reynolds-averaged method) is used to solve the global flow field of the ship. The VOF (Volume of Fluid) method is used to handle wave generation on the free surface, and the DBFI (Dynamic Fluid Body Interaction) method is used to handle the six-degree-of-freedom motion of the ship. This enables a detailed simulation of the flow field of the ship at different speeds. It can accurately capture the flow field gradient of the bow wave generation and the bottom boundary layer, improve the simulation accuracy of the ship flow field at different speeds, and provide reliable data support for the bubble risk assessment of acoustic equipment. The core equation in the RANS method is as follows:
[0027] In the above formula, Indicates fluid density; Indicates time; The horizontal component of the spatial coordinate system is represented by, where, The direction of the equation, For the direction of summation; where, The item is the first Each directional coordinate corresponds to the direction of the current momentum equation; The item is the first Three directional coordinates are used to represent spatial changes in three directions; Indicates speed, where, The direction of the velocity component, In which spatial direction does the velocity change? Indicates average pressure; Indicates the kinematic viscosity coefficient; The core equation in the VOF method is as follows:
[0028] In the above formula, This represents the volume fraction of a phase, i.e., the volume proportion of a certain phase in the control volume; in this embodiment, when When the value is 1, the grid is completely water. When the value is 0, the grid is completely empty. The time grid is located at the water-air interface; Indicates time; Represents the spatial differential operator; represents the divergence operation. Represents the fluid velocity vector; Indicates the interface compression speed or relative compression speed; In the DBFI (Dynamic Fluid Body Interaction) method, the equation of motion for a rigid body is as follows:
[0029] In the above formula, Indicates the mass of a rigid body; The vector representing the translational velocity of the rigid body's center of mass; Indicates time; This represents the net external force acting on a rigid body; The tensor of rotational inertia of a rigid body relative to its center of mass; Represents the angular velocity vector of a rigid body; This represents the net external torque acting on a rigid body; This embodiment is based on a ship with a bulbous bow, and the ship model constructed is as follows. Figure 1 As shown, S2. Define a key feature extraction area on the ship, including the bow wave breaking area and the surface area of the transducer mounting window of the acoustic equipment; arrange seed point groups in the key feature extraction area, extract feature streamlines passing through the seed point groups, and conduct a preliminary assessment of the bubble performance of the ship's acoustic equipment by tracing the coverage of the feature streamlines. When conducting a preliminary assessment of the bubble performance of marine acoustic equipment, it is necessary to assess whether the characteristic streamlines of the wave breaking area at the bow pass through the transducer mounting window of the acoustic equipment, and whether the characteristic streamlines of the surface area of the transducer mounting window of the acoustic equipment are smooth. Specifically, in this embodiment, for ships with bulbous bows, such as Figure 2 As shown, the ship's acoustic equipment is located on the bottom of the ship near the bow. The ship's acoustic equipment is as follows: Figure 2 The part circled in red in the middle; The seed point group includes a first seed point group arranged in the wave-breaking area at the bow of the ship, and a second seed point group arranged on the surface area of the transducer mounting window of the acoustic equipment. A first seed point group is deployed in the bow wave breaking zone (within a depth of 0.5m to 1m near the waterline). The first seed point group includes seed point arrays arranged laterally and longitudinally, based on the solved instantaneous velocity field of the flow field. The characteristic streamlines of each seed point in the first seed point subgroup are generated through the core streamline differential equation, thereby realizing the extraction of the characteristic streamlines of the first seed point subgroup; for ships with bulbous bows, the characteristic streamlines of the first seed point subgroup are as follows: Figure 3 As shown; The expression for the differential equation of the core streamline is as follows:
[0030] In the above formula, This represents the x-axis coordinate of the corresponding discrete point; This represents the ordinate of the corresponding discrete point; Represents the vertical axis coordinates of the corresponding discrete points; This represents the arc length of the one-dimensional pressure coefficient distribution curve; Indicates the velocity vector at Components in direction; Indicates the velocity vector at Components in direction; Indicates the velocity vector at Components in direction; This represents the magnitude of the resultant velocity, i.e., the modulus of the velocity vector; By analyzing the characteristic streamlines of each seed point in the first seed point subgroup, it can be preliminarily determined whether there may be a bubble cloud near the transducer of the acoustic device. Simultaneously, a second seed point group is arranged on the surface area of the acoustic equipment transducer mounting window. This second seed point group includes several seed points arranged along the surface of the transducer mounting window. For each seed point in the second seed point group, a backward integration is performed upstream (towards the bow), thereby generating the characteristic streamlines corresponding to each seed point in the second seed point group. The space defined by these characteristic streamlines is the influence envelope, thus achieving the extraction of the characteristic streamlines of the second seed point group. For ships with bulbous bows, the characteristic streamlines of the second seed point group are as follows: Figure 4 As shown, Figure 4 The area circled in red indicates the location of the ship's acoustic equipment; according to Figures 3-4 From the perspective of characteristic streamlines, stable characteristic streamlines in a flow field should be smooth, linear, or arc-shaped. If characteristic streamlines appear spiral or closed loops, it indicates that the flow has entered a three-dimensional separation region. If multiple characteristic streamlines rapidly converge to a straight line, it usually indicates that flow field separation has occurred at this point, and bubbles will accumulate along this line. If the axial velocity of the characteristic streamlines... Appearing in a certain area This indicates that there is backflow at that point, and the streamlines are drawn into the vortex.
[0031] S3. Extract the 3D spatial data of each discrete point on the feature streamline. The 3D spatial data of each discrete point on the feature streamline includes coordinates. velocity components and dimensionless pressure coefficient Pressure gradient analysis is performed on the characteristic streamlines, mapping the three-dimensional spatial data to a one-dimensional arc length function, thereby obtaining the one-dimensional pressure coefficient distribution curve along the characteristic streamline path. The expression of the one-dimensional pressure coefficient distribution curve is as follows:
[0032] In the formula, This represents the arc length of the one-dimensional pressure coefficient distribution curve; This represents the x-axis coordinate of the corresponding discrete point; This represents the ordinate of the corresponding discrete point; Represents the vertical axis coordinates of the corresponding discrete points; This represents the dimensionless pressure coefficient. This represents the pressure at the corresponding discrete point; Represents the hydrostatic pressure at infinity; Indicates fluid density; Indicates the incoming flow velocity; For ships with bulbous bows, the schematic diagram of the curve generated based on the expression of the one-dimensional pressure coefficient distribution curve is as follows: Figure 5 As shown, Figure 5 The diagram illustrates the pressure variation trend of the vessel from the bow starting point (s=0) along the centerline of the hull to the rear, and marks the sensitive areas of bubble performance; from Figure 5 The one-dimensional pressure coefficient distribution curve shown is analyzed. Within region I (from point A to point C), The pressure gradient rapidly decreases from 1.0 (stagnation point) to a negative value. (Down the pressure gradient), the fluid in At this time, the system is under strong acceleration. Although the bubbles generated in the bow wave breaking area enter the flow field here, due to the high flow velocity and thin boundary layer, the bubbles will pass through this area quickly, causing less interference to the transducers of the acoustic equipment. In area II (from point C to point E) It reaches its lowest point and then begins to rise, forming a pressure gradient.
[0033] (Against the pressure gradient), the pressure is lowest at point C, the bubble volume expands to its maximum, and scattering is strongest; from point C to point E, the fluid begins to decelerate, the backward resistance to the bubbles decreases, and the boundary layer begins to thicken, making it easy for bubbles to accumulate in this region; if the transducer is installed after point C and The price is still rising sharply, and bubble-shielded transducers pose a significant risk. In region III (from point E to point F) The pressure gradient tends to stabilize, approaching 0 or slightly positive. If the curve is smooth, it indicates isobaric flow, and the bubbles move steadily with the mainstream; if the curve recovers to its previous state... If the flow suddenly flattens out before 0 and a plateau appears that is far from 0, it indicates that flow field separation has occurred, and bubbles will enter the backflow vortex, causing acoustic equipment to fail. Simultaneously, the cavitation number is calculated near the acoustic device along the streamline, using the following formula:
[0034] In the above formula, This indicates the static pressure at that depth. This represents atmospheric pressure, approximately 1.013 × 10⁻⁶. 5 Pa; Indicates fluid density; Represents gravitational acceleration; Indicates the immersion depth of the acoustic equipment; Represents the vacuolation number; This represents the saturated vapor pressure of seawater, approximately 2340 Pa. Indicates the incoming flow velocity; If any point on the characteristic streamline satisfies the above formula, it means that cavitation noise has been generated on the path of the characteristic streamline, which will directly interfere with the normal operation of the acoustic equipment. Furthermore, a comprehensive index function is obtained based on the one-dimensional pressure coefficient distribution curve. Quantitative analysis of bubble performance in marine acoustic equipment, comprehensive index function. The expression is as follows:
[0035] In the formula, Indicates the endpoint of the assessment control area on the streamline; Indicates the starting point of the assessment control area on the streamline; Represents the weighting function; This represents the dimensionless pressure coefficient. This represents the arc length of the one-dimensional pressure coefficient distribution curve; The function combines the magnitude of pressure and the magnitude of the pressure gradient. Pressure affects bubble size, and the pressure gradient affects the degree of accumulation. It is expressed by the following formula:
[0036] In the above formula, This is a volume expansion term. The value ranges from 1.5 to 2.5; Represented as an accumulation term, The value ranges from 5 to 20. Generally, the value is 2; For cavitation effect terms, ; in, This represents the dimensionless pressure coefficient. Represents the vacuolation number; This represents the penalty steepness gain coefficient, with a value ranging from 10 to 20.
[0037] S4. Based on the one-dimensional pressure coefficient distribution curve and the criteria for evaluating the bubble performance of acoustic equipment, a final evaluation of the bubble performance of the ship's acoustic equipment is conducted. The criteria for evaluating the bubble performance of acoustic equipment include: When the coverage of the feature streamlines shows that all feature streamlines bypass the key area for feature extraction, the risk level is determined to be safe; at this time, the bubbles around the ship have no effect on the ship's acoustic equipment. When the coverage of the feature streamlines shows that some feature streamlines pass through the edge of the key area for feature extraction, the risk level is determined to be low risk. At this time, bubbles around the ship may cause occasional noise from the ship's acoustic equipment, which can be self-healed by increasing the speed. When the coverage of the feature streamlines shows that all or part of the feature streamlines cover the key area for feature extraction, the risk level is determined to be medium risk or high risk. When the risk level is determined to be medium or high, according to the one-dimensional pressure coefficient distribution curve, if the flow field section through which the feature streamlines covering the key area of feature extraction pass is in the isobaric zone, the risk level is determined to be medium. At this time, bubbles around the ship may cause the signal-to-noise ratio of the ship's acoustic equipment to decrease and the background noise to increase. If the flow field section through which the feature streamlines covering the key area of feature extraction pass is in the growth region, the risk level is determined to be high risk; at this time, bubbles around the ship may cause bubble shielding of the ship's acoustic equipment, resulting in a complete signal interruption. When the coverage area of the characteristic streamlines shows that all or part of the characteristic streamlines enter the recirculation zone, or when the coverage area of the characteristic streamlines shows that all or part of the characteristic streamlines enter the separation zone, the risk level is determined to be extreme risk. At this time, bubbles around the ship may cause bubble shielding phenomenon in the ship's acoustic equipment, accompanied by cavitation noise, and the equipment will not be able to work. The criteria for evaluating the bubble performance of acoustic devices are shown in Table 1: Table 1. Criteria for Evaluating the Bubble Performance of Acoustic Equipment
[0038] Based on Table 1, and by combining the characteristic streamlines extracted in step S2 and the one-dimensional pressure coefficient distribution curve obtained in step S3, the bubble performance of marine acoustic equipment can be qualitatively and quantitatively analyzed, thus achieving accurate evaluation.
[0039] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.
Claims
1. A method for evaluating the bubble performance of marine acoustic equipment, characterized in that: Includes the following steps: S1. Perform detailed simulation of the flow field of the ship at different speeds, divide the ship into local densification zones, and during the simulation, densify the local densification zones to capture the flow field gradient within the local densification zones; S2. Define a key area for feature extraction on the ship, arrange seed point groups in the key area for feature extraction, extract feature streamlines passing through the seed point groups, and conduct a preliminary evaluation of the bubble performance of the ship's acoustic equipment by tracking the coverage of the feature streamlines. S3. Extract the three-dimensional spatial data of each discrete point on the feature streamline, perform pressure gradient analysis on the feature streamline, and map the three-dimensional spatial data into a one-dimensional arc length function to obtain the one-dimensional pressure coefficient distribution curve along the feature streamline path. S4. Based on the one-dimensional pressure coefficient distribution curve and the criteria for evaluating the bubble performance of acoustic equipment, the bubble performance of the ship's acoustic equipment is evaluated in the final assessment.
2. The method for evaluating the bubble performance of marine acoustic equipment as described in claim 1, characterized in that: In S1, the RANS method is used to solve the global flow field of the ship, the VOF method is used to handle the wave-making of the free surface, and the DBFI method is used to handle the six-degree-of-freedom motion of the ship, thereby achieving a detailed simulation of the flow field of the ship at different speeds.
3. The method for evaluating the bubble performance of marine acoustic equipment as described in claim 1, characterized in that: In S1, the local encryption zone includes the bow wave-making area and the bottom boundary layer.
4. The method for evaluating the bubble performance of marine acoustic equipment as described in claim 1, characterized in that: In S2, the key areas for feature extraction include the bow wave breaking area and the surface area of the acoustic equipment transducer mounting window.
5. The method for evaluating the bubble performance of marine acoustic equipment as described in claim 4, characterized in that: In S2, when conducting a preliminary assessment of the bubble performance of the ship's acoustic equipment, it is assessed whether the characteristic streamlines of the wave breaking area at the bow pass through the acoustic equipment transducer mounting window, and whether the characteristic streamlines of the surface area of the acoustic equipment transducer mounting window are smooth.
6. The method for evaluating the bubble performance of marine acoustic equipment as described in claim 1, characterized in that: In S3, the three-dimensional spatial data of each discrete point on the feature streamline includes coordinates. velocity components and dimensionless pressure coefficient .
7. The method for evaluating the bubble performance of marine acoustic equipment as described in claim 6, characterized in that: In S3, the expression for the one-dimensional pressure coefficient distribution curve is as follows: In the formula, This represents the arc length of the one-dimensional pressure coefficient distribution curve; This represents the x-axis coordinate of the corresponding discrete point; This represents the ordinate of the corresponding discrete point; Represents the vertical axis coordinates of the corresponding discrete points; This represents the dimensionless pressure coefficient. This represents the pressure at the corresponding discrete point; Represents the hydrostatic pressure at infinity; Indicates fluid density; This indicates the incoming flow velocity.
8. The method for evaluating the bubble performance of marine acoustic equipment as described in claim 7, characterized in that: Based on the one-dimensional pressure coefficient distribution curve, the comprehensive index function is obtained. Quantitative analysis of bubble performance in marine acoustic equipment, comprehensive index function. The expression is as follows: In the formula, Indicates the endpoint of the assessment control area on the streamline; Indicates the starting point of the assessment control area on the streamline; Represents the weighting function; This represents the dimensionless pressure coefficient. This represents the arc length of the one-dimensional pressure coefficient distribution curve.
9. The method for evaluating the bubble performance of marine acoustic equipment as described in claim 1, characterized in that: The criteria for evaluating the bubble performance of acoustic devices include: When the coverage of the feature streamlines shows that all feature streamlines bypass the key area for feature extraction, the risk level is determined to be safe. When the coverage of the feature streamlines shows that some feature streamlines pass through the edge of the key area for feature extraction, the risk level is determined to be low risk. When the coverage of the feature streamlines shows that all or part of the feature streamlines cover the key area for feature extraction, the risk level is determined to be medium risk or high risk. When the coverage area of the characteristic streamlines shows that all or part of the characteristic streamlines enter the return flow zone, or when the coverage area of the characteristic streamlines shows that all or part of the characteristic streamlines enter the separation zone, the risk level is determined to be extreme risk.
10. The method for evaluating the bubble performance of marine acoustic equipment as described in claim 9, characterized in that: When the risk level is determined to be medium or high, according to the one-dimensional pressure coefficient distribution curve, if the flow field section through which the feature streamlines covering the key area of feature extraction pass is in the isobaric zone, the risk level is determined to be medium. If the flow field section traversed by the feature streamline covering the key area of feature extraction is in the growth region, the risk level is determined to be high risk.