Gas-liquid hole cavity characteristic frequency checking method, device and equipment

Abstract

The invention provides a gas-liquid hole cavity characteristic frequency checking method, device and equipment, and the method comprises the steps: predicting a shear oscillation frequency interval of a gas-liquid hole cavity according to the prediction range of the environment flow velocity outside the gas-liquid hole cavity; predicting a structural inherent frequency interval, a liquid cavity modal frequency interval, a gas cavity modal frequency interval and a sloshing frequency interval of the gas-liquid hole cavity by referring to a prediction range of a gas volume ratio in the gas-liquid hole cavity; the piston frequency interval of the gas-liquid hole cavity is predicted by referring to the prediction range of the gas volume ratio in the gas-liquid hole cavity and the prediction range of the environment pressure outside the gas-liquid hole cavity; and checking whether each of the structure inherent frequency interval, the liquid cavity modal frequency interval, the air cavity modal frequency interval, the sloshing frequency interval and the piston frequency interval meets the safety margin requirement relative to the shear oscillation frequency interval or not. According to the invention, the characteristic frequency of the gas-liquid pore cavity is checked, so that the problem of pore cavity resonance of a ship under common working conditions is avoided.

Description

Technical Field

[0001] The present application relates to the field of ship acoustic technology, and in particular to a method, device and equipment for calibrating characteristic frequency of a gas-liquid cavity. Background Art

[0002] Open cavities (hereinafter referred to as cavities) are common on ships, and common forms include sea-going tanks of ships, permeable structures with openings, etc. Figure 1 According to traditional theory, the cavity is filled with liquid, and its characteristic frequencies mainly include shear oscillation frequency, acoustic cavity modal frequency, structural natural frequency and Helmholtz frequency. Among them, the shear oscillation frequency is the excitation frequency, and the other three frequencies are the natural frequencies of the cavity system. When the excitation frequency coincides with the natural frequency of the system, resonance will be caused, which will bring serious safety hazards and noise problems to the ship. Therefore, during the design stage of the ship, it is generally necessary to check the characteristic frequency of the cavity to avoid cavity resonance problems under common working conditions.

[0003] However, in recent years, cavity resonance still exists in some actual ship tests, and the resonance frequency often deviates from the cavity characteristic frequency calibration result based on traditional theory. One of the reasons for this phenomenon is that the cavity is not always filled with liquid. During use, an indefinite amount of gas will be mixed into it. The introduction of gas causes a series of changes in the characteristic frequency of this type of gas-liquid cavity, making the cavity characteristic frequency calibration method based on traditional theory no longer applicable. Therefore, a characteristic frequency calibration method suitable for gas-liquid cavity is urgently needed. Summary of the invention

[0004] The present application provides a method, device and equipment for calibrating characteristic frequency of gas-liquid pores, which can solve the technical problem in the prior art that the method for calibrating characteristic frequency of pores based on traditional theory is not suitable for gas-liquid pores.

[0005] In a first aspect, an embodiment of the present application provides a method for calibrating characteristic frequency of a gas-liquid cavity, the method comprising:

[0006] The shear oscillation frequency range of the gas-liquid pore cavity is predicted by referring to the predicted range of the ambient flow velocity outside the gas-liquid pore cavity;

[0007] Referring to the predicted range of the gas volume ratio in the gas-liquid cavity, the structural natural frequency interval, the liquid cavity modal frequency interval, the gas cavity modal frequency interval and the sloshing frequency interval of the gas-liquid cavity are predicted, wherein when the gas volume ratio is less than the first ratio threshold, there is no sloshing frequency;

[0008] Referring to the predicted range of the gas volume ratio in the gas-liquid cavity and the predicted range of the ambient pressure outside the gas-liquid cavity, the piston frequency interval of the gas-liquid cavity is predicted, wherein when the gas volume ratio is less than the second ratio threshold, there is no piston frequency;

[0009] Check whether each of the structural natural frequency interval, the liquid cavity modal frequency interval, the gas cavity modal frequency interval, the sloshing frequency interval and the piston frequency interval meets the safety margin requirement relative to the shear oscillation frequency interval.

[0010] Further, in one embodiment, the step of predicting the piston frequency interval of the gas-liquid cavity includes:

[0011] The piston frequency at the minimum predicted ambient pressure when the gas-liquid cavity accounts for the maximum predicted proportion of the gas volume is predicted, denoted as f p_min ;

[0012] When the predicted gas-liquid cavity accounts for the larger value of the minimum predicted ratio and the second ratio threshold, the piston frequency at the maximum predicted ambient pressure is denoted as f p_max ;

[0013] The piston frequency interval F of the gas-liquid cavity p Determined as [f p_min ,f p_max ].

[0014] Furthermore, in one embodiment, the piston frequency of the gas-liquid cavity is predicted by a numerical simulation method, and the first-order frequency of the finite element model is used as the piston frequency of the gas-liquid cavity. The parameter setting requirements of the finite element model include:

[0015] The cavity, opening and external flow domain are geometrically established respectively with reference to the size parameters of the gas-liquid cavity. The cavity is divided into the gas cavity and the liquid cavity. The opening connects the cavity and the external flow domain. The ratios of the external flow domain and the opening in the length, width and height directions are all greater than or equal to 10.

[0016] All wall surfaces of the cavity and openings are assigned values ​​with reference to the structural material and thickness of the gas-liquid cavity;

[0017] The surface connecting the external flow domain and the gas-liquid pore cavity is set as an acoustic hard boundary, and the other surfaces of the external flow domain are set as acoustic soft boundaries;

[0018] Set all edges where the opening connects to the external flow domain as fixed constraints;

[0019] Make the interface between the air cavity and the liquid cavity, and the interface between the fluid and the wall meet the continuity conditions;

[0020] Adjust the gas density according to the ambient pressure.

[0021] Further, in one embodiment, the step of predicting the shear oscillation frequency interval of the gas-liquid cavity includes:

[0022] Predict the first-order shear oscillation frequency of the gas-liquid cavity at the minimum predicted ambient velocity, denoted as f s_min ;

[0023] Predict the third-order shear oscillation frequency of the gas-liquid cavity at the maximum predicted ambient flow rate, denoted as f s_max ;

[0024] The shear oscillation frequency interval F of the gas-liquid cavity s Determined as [f s_min ,f s_max ].

[0025] Further, in one embodiment, the shear oscillation frequency of the gas-liquid cavity is predicted by a first formula, and the first formula is:

[0026]

[0027] Among them, f s is the shear oscillation frequency, a is a constant, ranging from [0.47, 0.53], n s is the order of shear oscillation frequency, U is the ambient flow rate, L h It is the opening size of the gas-liquid cavity in the flow direction.

[0028] Furthermore, in one embodiment, the step of predicting the structural natural frequency interval of the gas-liquid cavity includes:

[0029] The first ten structural natural frequencies of the predicted gas-liquid pores when the gas volume accounts for the minimum predicted proportion are denoted by f str1_min 、f str2_min ,……,f str10_min ;

[0030] The first ten structural natural frequencies of the predicted gas-liquid pores when the gas volume accounts for the maximum predicted proportion are denoted by f str1_max 、f str2_max ,……,f str10_max ;

[0031] The structural natural frequency interval F of the gas-liquid cavity str Determined as [f str1_min ,f str1_max ]∪[f str2_min ,f str2_max ]∪…∪[f str10_min ,f str10_max ].

[0032] Furthermore, in one embodiment, the step of predicting the liquid cavity modal frequency interval and the gas cavity modal frequency interval of the gas-liquid cavity includes:

[0033] Predict all liquid cavity modal frequencies when the gas-liquid cavity accounts for the minimum predicted proportion of the gas volume and the modal order in each preset direction is 0, 1, or both, and not 0 at the same time. The minimum value is recorded as f l_min ;

[0034] The liquid cavity modal frequency interval F of the gas-liquid cavity l Determined as [f l_min ,+∞);

[0035] Predict all the air cavity modal frequencies when the gas volume is the maximum predicted ratio and the modal order in each preset direction is 0, 1, or both, and not 0 at the same time. The minimum value is recorded as f g_min ;

[0036] The air cavity modal frequency interval F of the air-liquid cavity g Determined as [f g_min ,+∞).

[0037] Further, in one embodiment, the step of predicting the sloshing frequency interval of the gas-liquid cavity includes:

[0038] The first-order sloshing frequency in the navigation direction when the gas-liquid cavity accounts for the maximum predicted proportion of the gas volume is predicted, denoted as f h_min ;

[0039] When the predicted gas-liquid cavity accounts for the larger value of the minimum predicted ratio and the first ratio threshold, the first-order sloshing frequency in the navigation direction is denoted as f h_max ;

[0040] The sloshing frequency interval F of the gas-liquid cavity h Determined as [f h_min ,f h_max ].

[0041] In a second aspect, the embodiment of the present application further provides a gas-liquid cavity characteristic frequency calibration device, the gas-liquid cavity characteristic frequency calibration device comprising:

[0042] A first prediction module is used to predict the shear oscillation frequency interval of the gas-liquid cavity with reference to the prediction range of the ambient flow rate outside the gas-liquid cavity;

[0043] The second prediction module is used to predict the structural natural frequency interval, liquid cavity modal frequency interval, gas cavity modal frequency interval and sloshing frequency interval of the gas-liquid cavity with reference to the prediction range of the gas volume ratio in the gas-liquid cavity, wherein when the gas volume ratio is less than the first ratio threshold, there is no sloshing frequency;

[0044] The third prediction module is used to predict the piston frequency interval of the gas-liquid cavity by referring to the predicted range of the gas volume ratio in the gas-liquid cavity and the predicted range of the ambient pressure outside the gas-liquid cavity, wherein when the gas volume ratio is less than the second ratio threshold, there is no piston frequency;

[0045] The frequency verification module is used to check whether each of the structural natural frequency interval, the liquid cavity modal frequency interval, the gas cavity modal frequency interval, the sloshing frequency interval and the piston frequency interval meets the safety margin requirement relative to the shear oscillation frequency interval.

[0046] In the third aspect, an embodiment of the present application also provides a gas-liquid pore cavity characteristic frequency calibration device, which includes a processor, a memory, and a gas-liquid pore cavity characteristic frequency calibration program stored in the memory and executable by the processor, wherein when the gas-liquid pore cavity characteristic frequency calibration program is executed by the processor, the steps of the above-mentioned gas-liquid pore cavity characteristic frequency calibration method are implemented.

[0047] In the present application, the characteristic frequencies of the gas-liquid pore cavity mainly include shear oscillation frequency, structural natural frequency, liquid cavity modal frequency, air cavity modal frequency, sloshing frequency and piston frequency. The shear oscillation frequency will be affected by the ambient flow velocity outside the gas-liquid pore cavity. The structural natural frequency, liquid cavity modal frequency, air cavity modal frequency, sloshing frequency and piston frequency will all be affected by the volume ratio of the gas in the gas-liquid pore cavity. The piston frequency will also be affected by the ambient pressure outside the gas-liquid pore cavity. The prediction of the characteristic frequency interval needs to refer to the prediction range of the corresponding influencing parameters, and finally check one by one whether the safety margin requirements are met. Through this application, the characteristic frequency of the gas-liquid pore cavity is checked, and the cavity design is guided in the ship design stage to avoid the cavity resonance problem under common working conditions of the ship. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a schematic diagram of the characteristic frequency of a pure liquid cavity in traditional theory;

[0049] Figure 2 This is a schematic diagram of the structure of the gas-liquid pore cavity in related research;

[0050] Figure 3 This is a schematic diagram of the characteristic frequency of the gas-liquid cavity in one embodiment of the present application;

[0051] Figure 4 This is a flow chart of a method for calibrating characteristic frequency of a gas-liquid cavity in one embodiment of the present application;

[0052] Figure 5 It is a schematic diagram of a numerical simulation model of the gas-liquid cavity piston frequency in one embodiment of the present application;

[0053] Figure 6This is a schematic diagram of the functional modules of a gas-liquid cavity characteristic frequency calibration device in one embodiment of the present application;

[0054] Figure 7 Schematic diagram of the hardware structure of the gas-liquid cavity characteristic frequency calibration device involved in the embodiment of the present application. DETAILED DESCRIPTION

[0055] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0056] Figure 2 The schematic diagram of the structure of the gas-liquid pore cavity in the related research is shown; Figure 3 A schematic diagram of the characteristic frequency of the gas-liquid cavity in one embodiment of the present application is shown.

[0057] Reference Figure 2 The cavity of the gas-liquid pore cavity contains both gas and liquid phases. There is a clear boundary between the two phases of media, and the media of the same phase in the cavity is continuous, that is, the gas and liquid are not mixed together in discrete forms, but exist independently in the form of layers. In the gas-liquid pore cavity, when the liquid in the cavity is disturbed, it will cause the gas in the cavity to expand / compress, thereby forming a pressure difference between the upper and lower surfaces of the liquid in the cavity, driving the liquid in the cavity to vibrate up and down. In this vibration mode, the liquid in the cavity moves in a form similar to a piston, so this movement is called piston motion. Piston motion is an inherent motion mode of the gas-liquid pore cavity. When the geometric and physical parameters of the gas-liquid pore cavity are certain, the frequency of its piston motion is fixed, so this frequency is called piston frequency.

[0058] In the gas-liquid cavity, the Helmholtz frequency is replaced by the piston frequency. The parametric mass of the Helmholtz frequency is the mass of the opening and its radiation-added mass. The piston frequency is different from this. The parametric mass is the mass of the opening + the mass of the liquid in the cavity + the radiation-added mass outside the cavity. The main reason for the above difference is that when the cavity is a single medium, the compressibility of the entire cavity medium provides stiffness for the system. When the cavity is a gas-liquid two-phase medium, the gas provides stiffness and the liquid provides mass.

[0059] Reference Figure 3When there are two-phase media of gas and liquid in the cavity, the existence of the free liquid surface will introduce not only the piston frequency but also the sloshing frequency. The gas and liquid will also divide the cavity into two parts, the gas cavity and the liquid cavity. The two parts have their own acoustic cavity modal frequencies, namely the liquid cavity modal frequency and the gas cavity modal frequency. Therefore, the characteristic frequencies of the gas-liquid pore cavity mainly include the shear oscillation frequency, the structural natural frequency, the liquid cavity modal frequency, the gas cavity modal frequency, the sloshing frequency and the piston frequency. The cavity characteristic frequency calibration method based on traditional theory is no longer applicable.

[0060] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0061] In a first aspect, an embodiment of the present application provides a method for calibrating the characteristic frequency of a gas-liquid cavity.

[0062] Figure 4 A schematic flow chart of a method for calibrating characteristic frequency of a gas-liquid cavity in one embodiment of the present application is shown.

[0063] Reference Figure 4 In one embodiment, the gas-liquid cavity characteristic frequency calibration method includes the following steps:

[0064] S1. Predict the shear oscillation frequency range of the gas-liquid cavity by referring to the predicted range of the ambient flow velocity outside the gas-liquid cavity.

[0065] Specifically, the shear oscillation frequency is affected by the ambient flow velocity. The greater the ambient flow velocity, the greater the shear oscillation frequency. The ambient flow velocity can give a prediction range based on the common speed of surface ships or underwater vehicles.

[0066] When predicting the shear oscillation frequency for a specific gas-liquid cavity, all parameters except the ambient flow rate can be fixed, such as the structural parameters of the gas-liquid cavity and the order of the shear oscillation frequency to be verified. Combined with the predicted range of the ambient flow rate, the shear oscillation frequency range of the gas-liquid cavity can be predicted according to theoretical formulas or numerical simulations.

[0067] S2. Referring to the predicted range of the gas volume ratio in the gas-liquid cavity, predict the structural natural frequency interval, liquid cavity modal frequency interval, gas cavity modal frequency interval and sloshing frequency interval of the gas-liquid cavity, wherein when the gas volume ratio is less than the first ratio threshold, there is no sloshing frequency.

[0068] Specifically, the natural frequency of the structure is affected by the added mass on the structure. The larger the gas volume ratio, the smaller the added mass and the larger the natural frequency of the structure. The liquid cavity modal frequency is affected by the size of the liquid cavity. The larger the gas volume ratio, the smaller the liquid cavity size and the larger the liquid cavity modal frequency. The air cavity modal frequency is affected by the size of the air cavity. The larger the gas volume ratio, the larger the air cavity size and the smaller the liquid cavity modal frequency. The sloshing frequency is affected by the depth of the liquid. The larger the gas volume ratio, the smaller the liquid depth and the smaller the sloshing frequency. The gas volume ratio can be given a prediction range based on actual experience. For example, in a normal cavity with an exhaust design, generally only a small amount of gas will remain that is difficult to discharge, and the gas volume ratio generally does not exceed 10%.

[0069] In particular, when the gas volume ratio is too low, the liquid surface easily touches the top surface of the cavity, making it difficult to form sloshing motion. Therefore, when predicting the sloshing frequency range, it is stipulated that when the gas volume ratio is less than the first ratio threshold, there is no sloshing frequency.

[0070] When predicting the structural natural frequency, liquid cavity modal frequency, air cavity modal frequency and sloshing frequency for a specific gas-liquid pore, all parameters except the gas volume fraction can be fixed, such as the structural parameters of the gas-liquid pore and the orders to be verified for the structural natural frequency, liquid cavity modal frequency, air cavity modal frequency and sloshing frequency. Combined with the predicted range of the gas volume fraction, the structural natural frequency range, liquid cavity modal frequency range, air cavity modal frequency range and sloshing frequency range of the gas-liquid pore can be predicted according to theoretical formulas or numerical simulations.

[0071] S3. Predict the piston frequency range of the gas-liquid pore cavity by referring to the predicted range of the gas volume ratio in the gas-liquid pore cavity and the predicted range of the ambient pressure outside the gas-liquid pore cavity, wherein when the gas volume ratio is less than the second ratio threshold, there is no piston frequency.

[0072] Specifically, the piston frequency is affected by the gas density. The larger the gas volume, the smaller the gas density, the smaller the piston frequency. The greater the ambient pressure, the greater the gas density, the greater the piston frequency. For surface ships, the ambient pressure can be set to standard atmospheric pressure. For underwater vehicles, the ambient pressure can be given a predicted range based on the common navigation depth of the underwater vehicle. The ambient pressure at the navigation depth H is P. H =P0+ρ l gH, where P0 is standard atmospheric pressure, ρ l is the liquid density and g is the acceleration due to gravity.

[0073] In particular, when the gas volume ratio is too low, the liquid surface easily touches the top surface of the cavity, making it difficult to form piston movement. Therefore, when predicting the piston frequency range, it is stipulated that when the gas volume ratio is less than the second ratio threshold, there is no piston frequency.

[0074] Optionally, the first ratio threshold and the second ratio threshold may be the same or different. For example, the first ratio threshold and the second ratio threshold are both set to 1%.

[0075] When predicting the piston frequency for a specific gas-liquid cavity, all parameters except the gas volume percentage can be fixed, such as the structural parameters of the gas-liquid cavity. Combined with the predicted range of the gas volume percentage and the ambient pressure, the piston frequency range of the gas-liquid cavity can be predicted according to theoretical formulas or numerical simulations.

[0076] S4. Check whether each of the structural natural frequency interval, the liquid cavity modal frequency interval, the gas cavity modal frequency interval, the sloshing frequency interval and the piston frequency interval meets the safety margin requirements relative to the shear oscillation frequency interval.

[0077] Specifically, the safety margin requirement is used to compensate for the error between the predicted frequency and the actual frequency, ensuring that the cavity resonance problem will not occur in the case of a small error. If the safety margin requirement is not met, it means that there is a resonance risk, and the cavity with the risk needs to be modified and re-calibrated.

[0078] For example, the shear oscillation frequency interval F of the gas-liquid cavity is s for [f s_min ,f s_max ], the safety margin requirement is the sum of the structural natural frequency interval, liquid cavity modal frequency interval, gas cavity modal frequency interval, sloshing frequency interval and piston frequency interval and [0.85f s_min ,1.15f s_max ]There is no intersection, that is, the frequency offset is 15%.

[0079] Therefore, in this embodiment, the characteristic frequencies of the gas-liquid cavity mainly include shear oscillation frequency, structural natural frequency, liquid cavity modal frequency, gas cavity modal frequency, sloshing frequency and piston frequency. The shear oscillation frequency will be affected by the ambient flow rate outside the gas-liquid cavity. The structural natural frequency, liquid cavity modal frequency, gas cavity modal frequency, sloshing frequency and piston frequency will all be affected by the volume ratio of gas in the gas-liquid cavity. The piston frequency will also be affected by the ambient pressure outside the gas-liquid cavity. The prediction of the characteristic frequency interval needs to refer to the prediction range of the corresponding influencing parameters, and finally check one by one whether the safety margin requirements are met. Through this embodiment, the characteristic frequency of the gas-liquid cavity is checked, and the cavity design is guided in the ship design stage to avoid the cavity resonance problem under common working conditions of the ship.

[0080] Further, in one embodiment, the step of predicting the shear oscillation frequency interval of the gas-liquid cavity includes:

[0081] Predict the first-order shear oscillation frequency of the gas-liquid cavity at the minimum predicted ambient velocity, denoted as f s_min ;

[0082] Predict the third-order shear oscillation frequency of the gas-liquid cavity at the maximum predicted ambient flow rate, denoted as f s_max ;

[0083] The shear oscillation frequency interval F of the gas-liquid cavity s Determined as [f s_min ,f s_max ].

[0084] In this embodiment, the first three order shear oscillation frequencies are calibrated to cover common working conditions. According to practical experience, within the predicted range of ambient flow rate, the range corresponding to the first three order shear oscillation frequencies is usually continuous, and only two boundary values ​​need to be calculated to obtain the shear oscillation frequency interval.

[0085] Further, in one embodiment, the shear oscillation frequency of the gas-liquid cavity is predicted by a first formula, and the first formula is:

[0086]

[0087] Among them, f s is the shear oscillation frequency, a is a constant, ranging from [0.47, 0.53], n s is the order of shear oscillation frequency, U is the ambient flow rate, L h It is the opening size of the gas-liquid cavity in the flow direction.

[0088] Through this embodiment, the shear oscillation frequency can be predicted quickly and accurately.

[0089] For example, there is a sea-connected liquid tank on the underwater vehicle. The liquid tank is in the shape of a cube, and the cavity length L q =0.5m, width W q =0.3m, height D q =1m. There is a rectangular hole at the bottom of the tank, with a length of L h =0.2m, width W h =0.2m, height D h =0.01m. Assume that the common speed range of underwater vehicles is 1-9m / s, the common navigation depth is 0-200m, and the predicted range of gas volume ratio is 0-10%.

[0090] The first three-order shear oscillation frequencies are calculated using the first formula, and the results are shown in Table 1.

[0091] Table 1

[0092] Environmental flow rate (m / s) <![CDATA[f s1 (Hz)]]> <![CDATA[f s2 (Hz)]]> <![CDATA[f s3 (Hz)]]> 1 2.4 4.7 7.1 2 4.7 9.5 14.2 3 7.1 14.2 21.3 4 9.5 18.9 28.4 5 11.8 23.6 35.4 6 14.2 28.4 42.5 7 16.5 33.1 49.6 8 18.9 37.8 56.7 9 21.3 42.5 63.8

[0093] It can be seen that the range corresponding to the shear oscillation frequency of the first three orders is continuous, f s_min =2.4Hz, f s_max =63.8Hz, F s =[2.4Hz,63.8Hz].

[0094] Furthermore, in one embodiment, the step of predicting the structural natural frequency interval of the gas-liquid cavity includes:

[0095] The first ten structural natural frequencies of the predicted gas-liquid pores when the gas volume accounts for the minimum predicted proportion are denoted by f str1_min 、f str2_min ,……,f str10_min ;

[0096] The first ten structural natural frequencies of the predicted gas-liquid pores when the gas volume accounts for the maximum predicted proportion are denoted as f str1_max 、f str2_max ,……,f str10_max ;

[0097] The structural natural frequency interval F of the gas-liquid cavity str Determined as [f str1_min ,f str1_max ]∪[f str2_min ,f str2_max ]∪…∪[f str10_min ,f str10_max ].

[0098] In this embodiment, the first ten orders of structural natural frequencies are checked to cover common working conditions. According to practical experience, within the predicted range of gas volume percentage, the range corresponding to the first ten orders of structural natural frequencies is usually discontinuous. Two boundary values ​​need to be calculated for each order to form ten sub-intervals. The structural natural frequency interval is obtained by taking the union of the ten sub-intervals.

[0099] For example, the relevant parameters of the aforementioned sea-going liquid tank are used, and the numerical simulation method is used to calculate the first ten structural natural frequencies when the gas volume accounts for 0% and 10% respectively. The results are shown in Table 2.

[0100] Table 2

[0101] Degree <![CDATA[f str_min (Hz)]]> <![CDATA[f str_max (Hz)]]> 1 176.3 179.4 2 211.6 229.2 3 230.1 232.2 4 242.9 268.7 5 320.4 346.8 6 353.0 361.3 7 370.3 380.2 8 479.0 488.5 9 479.4 490.7 10 511.3 533.6

[0102] It can be seen that the range corresponding to the first ten orders of structural natural frequencies is discontinuous, f str1_min =176.3Hz, f str2_min =211.6Hz, ..., f str10_min =511.3Hz, f str1_ma =179.4Hz, f str2_max =229.2Hz, ..., fstr10_max =533.6Hz, F str =[176.3Hz,179.4Hz]∪[211.6Hz,229.2Hz]∪…∪[511.3Hz,533.6Hz].

[0103] Furthermore, the step of predicting the liquid cavity modal frequency interval and the gas cavity modal frequency interval of the gas-liquid cavity includes:

[0104] Predict all liquid cavity modal frequencies when the gas-liquid cavity accounts for the minimum predicted proportion of the gas volume and the modal order in each preset direction is 0, 1, or both, and not 0 at the same time. The minimum value is recorded as f l_min ;

[0105] The liquid cavity modal frequency interval F of the gas-liquid cavity l Determined as [f l_min ,+∞);

[0106] Predict all the air cavity modal frequencies when the gas volume is the maximum predicted ratio and the modal order in each preset direction is 0, 1, or both, and not 0 at the same time. The minimum value is recorded as f g_min ;

[0107] The air cavity modal frequency interval F of the air-liquid cavity g Determined as [f g_min ,+∞).

[0108] In this embodiment, due to the limited speed of the ship, according to practical experience, the shear oscillation frequency usually does not exceed 200 Hz, while the acoustic cavity modal frequency can easily exceed 200 Hz. Therefore, only the minimum acoustic cavity modal frequency that may occur is predicted, and the maximum acoustic cavity modal frequency that may occur is assumed to be greater than the maximum shear oscillation frequency that may occur, that is, only the lower boundary value is calculated for the liquid cavity modal frequency and the air cavity modal frequency, and the upper boundary value is equivalently set to positive infinity. The acoustic cavity modal frequency needs to superimpose the modal frequencies of multiple preset directions, and the modal orders of each preset direction can be different, but cannot be 0 at the same time. The minimum acoustic cavity modal frequency must appear in the case where the modal order of each preset direction is one of 0 and 1, so this embodiment calculates all the acoustic cavity modal frequencies corresponding to these modal orders, and selects the minimum value as the lower boundary value.

[0109] For example, the liquid cavity modal frequency of the gas-liquid cavity is predicted by the second formula, which is:

[0110]

[0111] The air cavity modal frequency of the air-liquid cavity is predicted by the third formula, which is:

[0112]

[0113] Among them, f l is the liquid cavity modal frequency, c l is the liquid sound speed, f g is the cavity modal frequency, c g is the gas sound speed, L l , W l , D l are the length, width and depth of the liquid cavity, L g , W g , D g are the length, width and depth of the air cavity respectively. For irregular cavities, the maximum values ​​of length, width and height are taken. x 、n y 、n z are the modal orders in length, width and height directions respectively.

[0114] Using the relevant parameters of the aforementioned sea-going tank, when the gas volume ratio is 0, L l =L q =0.5m, W l =W q =0.3m, D l =D q =1m, take c l =1482.1m / s, the second formula is used to calculate all liquid cavity modal frequencies when the modal orders in the length, width and height directions are either 0 or 1 but not 0 at the same time. The results are shown in Table 3.

[0115] Table 3

[0116] Degree (length, width, height) <![CDATA[f l (Hz)]]> (0,0,1) 741.1 (0,1,0) 2470.2 (0,1,1) 2578.9 (1,0,0) 1482.1 (1,0,1) 1657.0 (1,1,0) 2880.7 (1,1,1) 2974.5

[0117] It can be seen that f l_min =741.1Hz, F l =[741.1Hz,+∞).

[0118] When the gas volume accounts for 10%, L g =L q =0.5m, W g =W q =0.3m, D g =0.1D q =0.1m, take c g =346.25m / s, the third formula is used to calculate all the air cavity modal frequencies when the modal orders in the length, width and height directions are either 0 or 1 but not 0 at the same time. The results are shown in Table 4.

[0119] Table 4

[0120] Degree (length, width, height) <![CDATA[f g (Hz)]]> (1,0,0) 346.3 (0,1,0) 577.1 (1,1,0) 673.0 (0,0,1) 1731.3 (1,0,1) 1765.5 (0,1,1) 1824.9 (1,1,1) 1857.5

[0121] It can be seen that f g_min =346.3Hz, F g =[346.3Hz,+∞).

[0122] Further, in one embodiment, the step of predicting the sloshing frequency interval of the gas-liquid cavity includes:

[0123] The first-order sloshing frequency in the navigation direction when the gas-liquid cavity accounts for the maximum predicted proportion of the gas volume is predicted, denoted as f h_min ;

[0124] When the predicted gas-liquid cavity accounts for the larger value of the minimum predicted ratio and the first ratio threshold, the first-order sloshing frequency in the navigation direction is denoted as f h_max ;

[0125] The sloshing frequency interval F of the gas-liquid cavity h Determined as [f h_min ,f h_max ].

[0126] In this embodiment, according to actual experience, sloshing motions of the second order or higher are difficult to excite and difficult to maintain after excitation. Only the first order sloshing frequency is checked, which can cover common working conditions. In addition, for the same gas-liquid cavity, the sloshing length will be different when sloshing in different directions. The larger the sloshing length, the smaller the sloshing frequency. In the ship scene, the sloshing direction is usually consistent with the sailing direction, and sloshing motions in other directions will basically not occur.

[0127] For example, the sloshing frequency of the gas-liquid cavity is predicted by the fourth formula, which is:

[0128]

[0129] Among them, f h is the sloshing frequency, g is the gravitational acceleration, n h is the order of the sloshing frequency, L h is the sloshing length, D h is the liquid depth.

[0130] The relevant parameters of the aforementioned sea-going liquid tank are used, and the sailing direction is taken as the length direction of the sea-going liquid tank, L h =L q =0.5m, the first ratio threshold is 1%, which is greater than the minimum predicted ratio of 0. When the gas volume accounts for 10%, D h_min =0.9D q =0.9m, when the gas volume accounts for 1%, D h_max =0.99D q =0.99m. Using the fourth formula, we can get f h_min=1.24887Hz, f h_max =1.24888Hz, F h =[1.24887Hz,1.24888Hz].

[0131] Further, in one embodiment, the step of predicting the piston frequency interval of the gas-liquid cavity includes:

[0132] The piston frequency at the minimum predicted ambient pressure when the gas-liquid cavity accounts for the maximum predicted proportion of the gas volume is predicted, denoted as f p_min ;

[0133] When the predicted gas-liquid cavity accounts for the larger value of the minimum predicted ratio and the second ratio threshold, the piston frequency at the maximum predicted ambient pressure is denoted as f p_max ;

[0134] The piston frequency interval F of the gas-liquid cavity p Determined as [f p_min ,f p_max ].

[0135] Specifically, the theoretical calculation method of piston frequency can refer to CN202410881964-A method and system for predicting piston frequency of a gas-liquid two-phase medium opening cavity. This paper mainly describes the numerical simulation method.

[0136] Figure 5 A schematic diagram of a numerical simulation model of the gas-liquid cavity piston frequency in one embodiment of the present application is shown.

[0137] Reference Figure 5 , the piston frequency of the gas-liquid cavity is predicted by numerical simulation method, and the first-order frequency of the finite element model is used as the piston frequency of the gas-liquid cavity. The parameter setting requirements of the finite element model include:

[0138] The cavity, opening and external flow domain are geometrically established with reference to the size parameters of the gas-liquid cavity. The cavity is divided into the gas cavity and the liquid cavity. The opening connects the cavity and the external flow domain. The ratios of the external flow domain and the opening in length, width and height are all greater than or equal to 10. That is, if the length, width and height of the opening are H_L, H_W and H_D respectively, and the length, width and height of the external flow domain are F_L, F_W and F_D respectively, then the following should be satisfied:

[0139]

[0140] The structural material and thickness of the gas-liquid cavity are referenced to assign values ​​to all the walls of the cavity and the opening to reflect the effect of structural elasticity on the piston frequency;

[0141] The surface connecting the external flow domain and the gas-liquid cavity is set as an acoustic hard boundary, that is, the normal vibration acceleration is 0, and the other surfaces of the external flow domain are set as acoustic soft boundaries, that is, the normal sound pressure is 0;

[0142] Set all edges where the opening connects to the external flow domain as fixed constraints, i.e. the displacements in the x, y, and z directions are 0;

[0143] Make the interface between the air cavity and the liquid cavity, and the interface between the fluid and the wall meet the continuity conditions, that is, the pressure and vibration velocity are equal;

[0144] Adjust the gas density according to the ambient pressure. When the ambient pressure is P, the gas density is Among them, P0 is the standard atmospheric pressure and ρ0 is the gas density under standard atmospheric pressure.

[0145] The relevant parameters of the aforementioned sea-going tank are used, and the second ratio threshold is taken as 1%, which is greater than the minimum predicted ratio of 0. Assume that the ambient pressure P0 at a depth of 0m is 1×10e5Pa, and the ambient pressure P at a depth of 200m is H =20.62×10e5Pa. Using numerical simulation method, the piston frequency f at P0=1×10e5Pa is obtained when the gas volume accounts for 10% p_min =2.2Hz, when the gas volume accounts for 1%, at P H = Piston frequency f at 20.62×10e5Pa p_max =69.1Hz, F p =[2.2Hz,69.1Hz].

[0146] According to the above embodiment, F s 、F str 、F l 、F g 、F h 、F p , set the safety margin requirement to 15% frequency stagger, and calculate F s ′=[0.85f s_min ,1.15f s_max ]=[2.0Hz,73.4Hz], we find that F p With F s ' There is an intersection, indicating that there is a risk of piston frequency resonance. It is possible to consider tilting the top surface of the cavity to concentrate the gas in the cavity to the highest point in the cavity, which is convenient for centralized degassing and makes the gas volume account for less than 1%, thereby eliminating piston movement.

[0147] In a second aspect, an embodiment of the present application also provides a gas-liquid cavity characteristic frequency calibration device.

[0148] Figure 6A schematic diagram of the functional modules of a gas-liquid cavity characteristic frequency calibration device in one embodiment of the present application is shown.

[0149] Reference Figure 6 In one embodiment, the gas-liquid cavity characteristic frequency calibration device includes:

[0150] A first prediction module 10 is used to predict the shear oscillation frequency interval of the gas-liquid cavity with reference to the prediction range of the ambient flow rate outside the gas-liquid cavity;

[0151] The second prediction module 20 is used to predict the structural natural frequency interval, liquid cavity modal frequency interval, gas cavity modal frequency interval and sloshing frequency interval of the gas-liquid cavity with reference to the predicted range of the gas volume ratio in the gas-liquid cavity, wherein when the gas volume ratio is less than the first ratio threshold, there is no sloshing frequency;

[0152] The third prediction module 30 is used to predict the piston frequency interval of the gas-liquid cavity by referring to the predicted range of the gas volume ratio in the gas-liquid cavity and the predicted range of the ambient pressure outside the gas-liquid cavity, wherein when the gas volume ratio is less than the second ratio threshold, there is no piston frequency;

[0153] The frequency checking module 40 is used to check whether each of the structural natural frequency interval, the liquid cavity modal frequency interval, the gas cavity modal frequency interval, the sloshing frequency interval and the piston frequency interval meets the safety margin requirement relative to the shear oscillation frequency interval.

[0154] Furthermore, in one embodiment, the third prediction module 30 is used to:

[0155] The piston frequency at the minimum predicted ambient pressure when the gas-liquid cavity accounts for the maximum predicted proportion of the gas volume is predicted, denoted as f p_min ;

[0156] When the predicted gas-liquid cavity accounts for the larger value of the minimum predicted ratio and the second ratio threshold, the piston frequency at the maximum predicted ambient pressure is denoted as f p_max ;

[0157] The piston frequency interval F of the gas-liquid cavity p Determined as [f p_min ,f p_max ].

[0158] Furthermore, in one embodiment, the third prediction module 30 is used to:

[0159] The piston frequency of the gas-liquid cavity is predicted by numerical simulation method, and the first-order frequency of the finite element model is used as the piston frequency of the gas-liquid cavity. The parameter setting requirements of the finite element model include:

[0160] The cavity, opening and external flow domain are geometrically established respectively with reference to the size parameters of the gas-liquid cavity. The cavity is divided into the gas cavity and the liquid cavity. The opening connects the cavity and the external flow domain. The ratios of the external flow domain and the opening in the length, width and height directions are all greater than or equal to 10.

[0161] All wall surfaces of the cavity and openings are assigned values ​​with reference to the structural material and thickness of the gas-liquid cavity;

[0162] The surface connecting the external flow domain and the gas-liquid pore cavity is set as an acoustic hard boundary, and the other surfaces of the external flow domain are set as acoustic soft boundaries;

[0163] Set all edges where the opening connects to the external flow domain as fixed constraints;

[0164] Make the interface between the air cavity and the liquid cavity, and the interface between the fluid and the wall meet the continuity conditions;

[0165] Adjust the gas density according to the ambient pressure.

[0166] Furthermore, in one embodiment, the second prediction module 20 is used to:

[0167] Predict the first-order shear oscillation frequency of the gas-liquid cavity at the minimum predicted ambient velocity, denoted as f s_min ;

[0168] Predict the third-order shear oscillation frequency of the gas-liquid cavity at the maximum predicted ambient flow rate, denoted as f s_max ;

[0169] The shear oscillation frequency interval F of the gas-liquid cavity s Determined as [f s_min ,f s_max ].

[0170] Furthermore, in one embodiment, the second prediction module 20 is used to:

[0171] The shear oscillation frequency of the gas-liquid cavity is predicted by the first formula, which is:

[0172]

[0173] Among them, f s is the shear oscillation frequency, a is a constant, ranging from [0.47, 0.53], n s is the order of shear oscillation frequency, U is the ambient flow rate, L h It is the opening size of the gas-liquid cavity in the flow direction.

[0174] Furthermore, in one embodiment, the second prediction module 20 is used to:

[0175] The first ten structural natural frequencies of the predicted gas-liquid pores when the gas volume accounts for the minimum predicted proportion are denoted by f str1_min 、f str2_min ,……,f str10_min ;

[0176] The first ten structural natural frequencies of the predicted gas-liquid pores when the gas volume accounts for the maximum predicted proportion are denoted as f str1_max 、f str2_max ,……,f str10_max ;

[0177] The structural natural frequency interval F of the gas-liquid cavity str Determined as [f str1_min ,f str1_max ]∪[f str2_min ,f str2_max ]∪…∪[f str10_min ,f str10_max ].

[0178] Furthermore, in one embodiment, the second prediction module 20 is used to:

[0179] Predict all liquid cavity modal frequencies when the gas-liquid cavity accounts for the minimum predicted proportion of the gas volume and the modal order in each preset direction is 0, 1, or both, and not 0 at the same time. The minimum value is recorded as f l_min ;

[0180] The liquid cavity modal frequency interval F of the gas-liquid cavity l Determined as [f l_min ,+∞);

[0181] Predict all the air cavity modal frequencies when the gas volume is the maximum predicted ratio and the modal order in each preset direction is 0, 1, or both, and not 0 at the same time. The minimum value is recorded as f g_min ;

[0182] The air cavity modal frequency interval F of the air-liquid cavity g Determined as [f g_min ,+∞).

[0183] Furthermore, in one embodiment, the second prediction module 20 is used to:

[0184] The steps for predicting the sloshing frequency range of the gas-liquid cavity include:

[0185] The first-order sloshing frequency in the navigation direction when the gas-liquid cavity accounts for the maximum predicted proportion of the gas volume is predicted, denoted as f h_min ;

[0186] When the predicted gas-liquid cavity accounts for the larger value of the minimum predicted ratio and the first ratio threshold, the first-order sloshing frequency in the navigation direction is denoted as f h_max ;

[0187] The sloshing frequency interval F of the gas-liquid cavity h Determined as [f h_min ,f h_max ].

[0188] Among them, the functional implementation of each module in the above-mentioned gas-liquid pore cavity characteristic frequency calibration device corresponds to the various steps in the above-mentioned gas-liquid pore cavity characteristic frequency calibration method embodiment, and its functions and implementation processes are no longer repeated here one by one.

[0189] In a third aspect, an embodiment of the present application provides a gas-liquid pore cavity characteristic frequency calibration device, which can be a personal computer (PC), a laptop computer, a server, or other device with data processing capabilities.

[0190] Figure 7 A schematic diagram of the hardware structure of the gas-liquid cavity characteristic frequency calibration device involved in the embodiment of the present application is shown.

[0191] Reference Figure 7 In an embodiment of the present application, the gas-liquid cavity characteristic frequency calibration device may include a processor, a memory, a communication interface, and a communication bus.

[0192] The communication bus may be of any type and is used to interconnect the processor, the memory, and the communication interface.

[0193] The communication interface includes an input / output (I / O) interface, a physical interface, and a logical interface, which are used to interconnect the devices inside the gas-liquid cavity characteristic frequency calibration device, and an interface used to interconnect the gas-liquid cavity characteristic frequency calibration device with other devices (such as other computing devices or user devices). The physical interface can be an Ethernet interface, an optical fiber interface, an ATM interface, etc.; the user device can be a display, a keyboard, etc.

[0194] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0195] The processor may be a general-purpose processor, which may call the gas-liquid pore cavity characteristic frequency calibration program stored in the memory and execute the gas-liquid pore cavity characteristic frequency calibration method provided in the embodiment of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the gas-liquid pore cavity characteristic frequency calibration program is called may refer to the various embodiments of the gas-liquid pore cavity characteristic frequency calibration method of the present application, which will not be described in detail here.

[0196] Those skilled in the art will understand that Figure 7 The hardware structure shown in the figure does not constitute a limitation on the present application, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0197] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are only for description and do not represent the advantages or disadvantages of the embodiments.

[0198] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit "first", "second" and "third" to different types.

[0199] In the description of the embodiments of the present application, "exemplary", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary", "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a specific way.

[0200] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; the “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0201] In some processes described in the embodiments of the present application, multiple operations or steps that appear in a specific order are included, but it should be understood that these operations or steps may not be executed in the order in which they appear in the embodiments of the present application or in parallel, and the sequence number of the operation is only used to distinguish the different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed in sequence or in parallel, and these operations or steps may be combined.

[0202] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, disk, CD) as described above, and includes a number of instructions for a terminal device to execute the methods described in each embodiment of the present application.

[0203] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for calibrating characteristic frequency of gas-liquid cavity, characterized in that: The gas-liquid cavity characteristic frequency calibration method comprises: The shear oscillation frequency range of the gas-liquid pore cavity is predicted by referring to the predicted range of the ambient flow velocity outside the gas-liquid pore cavity; Referring to the predicted range of the gas volume ratio in the gas-liquid cavity, the structural natural frequency interval, the liquid cavity modal frequency interval, the gas cavity modal frequency interval and the sloshing frequency interval of the gas-liquid cavity are predicted, wherein when the gas volume ratio is less than the first ratio threshold, there is no sloshing frequency; Referring to the predicted range of the gas volume ratio in the gas-liquid cavity and the predicted range of the ambient pressure outside the gas-liquid cavity, the piston frequency interval of the gas-liquid cavity is predicted, wherein when the gas volume ratio is less than the second ratio threshold, there is no piston frequency; Check whether each of the structural natural frequency interval, the liquid cavity modal frequency interval, the gas cavity modal frequency interval, the sloshing frequency interval and the piston frequency interval meets the safety margin requirement relative to the shear oscillation frequency interval.

2. The gas-liquid cavity characteristic frequency calibration method according to claim 1, characterized in that: The steps for predicting the piston frequency interval of the gas-liquid cavity include: The piston frequency at the minimum predicted ambient pressure when the gas-liquid cavity accounts for the maximum predicted proportion of the gas volume is predicted, denoted as f p_min ; When the predicted gas-liquid cavity accounts for the larger value of the minimum predicted ratio and the second ratio threshold, the piston frequency at the maximum predicted ambient pressure is denoted as f p_max ; The piston frequency interval F of the gas-liquid cavity p Determined as [f p_min ,f p_max ].

3. The gas-liquid cavity characteristic frequency calibration method according to claim 1, characterized in that: The piston frequency of the gas-liquid cavity is predicted by numerical simulation method, and the first-order frequency of the finite element model is used as the piston frequency of the gas-liquid cavity. The parameter setting requirements of the finite element model include: The cavity, opening and external flow domain are geometrically established respectively with reference to the size parameters of the gas-liquid cavity. The cavity is divided into the gas cavity and the liquid cavity. The opening connects the cavity and the external flow domain. The ratios of the external flow domain and the opening in the length, width and height directions are all greater than or equal to 10. All wall surfaces of the cavity and openings are assigned values ​​with reference to the structural material and thickness of the gas-liquid cavity; The surface connecting the external flow domain and the gas-liquid pore cavity is set as an acoustic hard boundary, and the other surfaces of the external flow domain are set as acoustic soft boundaries; Set all edges where the opening connects to the external flow domain as fixed constraints; Make the interface between the air cavity and the liquid cavity, and the interface between the fluid and the wall meet the continuity conditions; Adjust the gas density according to the ambient pressure.

4. The gas-liquid cavity characteristic frequency calibration method according to claim 1, characterized in that: The steps of predicting the shear oscillation frequency interval of the gas-liquid cavity include: Predict the first-order shear oscillation frequency of the gas-liquid cavity at the minimum predicted ambient velocity, denoted as f s_min ; Predict the third-order shear oscillation frequency of the gas-liquid cavity at the maximum predicted ambient flow rate, denoted as f s_max ; The shear oscillation frequency interval F of the gas-liquid cavity s Determined as [f s_min ,f s_max ].

5. The gas-liquid cavity characteristic frequency calibration method according to claim 1, characterized in that: The shear oscillation frequency of the gas-liquid cavity is predicted by the first formula, which is: Among them, f s is the shear oscillation frequency, a is a constant, ranging from [0.47, 0.53], n s is the order of shear oscillation frequency, U is the ambient flow rate, L h It is the opening size of the gas-liquid cavity in the flow direction.

6. The gas-liquid cavity characteristic frequency calibration method according to claim 1, characterized in that: The steps for predicting the structural natural frequency range of the gas-liquid cavity include: The first ten structural natural frequencies of the predicted gas-liquid pores when the gas volume accounts for the minimum predicted proportion are denoted by f str1_min 、f str2_min ,……,f str10_min ; The first ten structural natural frequencies of the predicted gas-liquid pores when the gas volume accounts for the maximum predicted proportion are denoted by f str1_max 、f str2_max ,……,f str10_max ; The structural natural frequency interval F of the gas-liquid cavity str Determined as [f str1_min ,f str1_max ]∪[f str2_min ,f str2_max ]∪…∪[f str10_min ,f str10_max ].

7. The gas-liquid cavity characteristic frequency calibration method according to claim 1, characterized in that: The steps of predicting the liquid cavity modal frequency interval and the gas cavity modal frequency interval of the gas-liquid pore cavity include: Predict all liquid cavity modal frequencies when the gas-liquid cavity accounts for the minimum predicted proportion of the gas volume and the modal order in each preset direction is 0, 1, or both, and not 0 at the same time. The minimum value is recorded as f l_min ; The liquid cavity modal frequency interval F of the gas-liquid cavity l Determined as [f l_min ,+∞); Predict all the air cavity modal frequencies when the gas volume is the maximum predicted ratio and the modal order in each preset direction is 0, 1, or both, and not 0 at the same time. The minimum value is recorded as f g_min ; The air cavity modal frequency interval F of the air-liquid cavity g Determined as [f g_min ,+∞).

8. The gas-liquid cavity characteristic frequency calibration method according to claim 1, characterized in that: The steps for predicting the sloshing frequency range of the gas-liquid cavity include: The first-order sloshing frequency in the navigation direction when the gas-liquid cavity accounts for the maximum predicted proportion of the gas volume is predicted, denoted as f h_min ; When the predicted gas-liquid cavity accounts for the larger value of the minimum predicted ratio and the first ratio threshold, the first-order sloshing frequency in the navigation direction is denoted as f h_max ; The sloshing frequency interval F of the gas-liquid cavity h Determined as [f h_min ,f h_max ].

9. A gas-liquid cavity characteristic frequency calibration device, characterized in that: The gas-liquid cavity characteristic frequency calibration device comprises: A first prediction module is used to predict the shear oscillation frequency interval of the gas-liquid cavity with reference to the prediction range of the ambient flow rate outside the gas-liquid cavity; The second prediction module is used to predict the structural natural frequency interval, liquid cavity modal frequency interval, gas cavity modal frequency interval and sloshing frequency interval of the gas-liquid cavity with reference to the prediction range of the gas volume ratio in the gas-liquid cavity, wherein when the gas volume ratio is less than the first ratio threshold, there is no sloshing frequency; The third prediction module is used to predict the piston frequency interval of the gas-liquid cavity by referring to the predicted range of the gas volume ratio in the gas-liquid cavity and the predicted range of the ambient pressure outside the gas-liquid cavity, wherein when the gas volume ratio is less than the second ratio threshold, there is no piston frequency; The frequency verification module is used to check whether each of the structural natural frequency interval, the liquid cavity modal frequency interval, the gas cavity modal frequency interval, the sloshing frequency interval and the piston frequency interval meets the safety margin requirement relative to the shear oscillation frequency interval.

10. A gas-liquid cavity characteristic frequency calibration device, characterized in that: The gas-liquid pore cavity characteristic frequency calibration device includes a processor, a memory, and a gas-liquid pore cavity characteristic frequency calibration program stored in the memory and executable by the processor, wherein when the gas-liquid pore cavity characteristic frequency calibration program is executed by the processor, the steps of the gas-liquid pore cavity characteristic frequency calibration method as described in any one of claims 1 to 8 are implemented.

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