Method and system for calculating motion state and collision result of raindrops in wind field of typhoon

Abstract

To provide a method and a system related to weather and climate technical fields for calculating a motion state and a collision result of raindrops in a wind field of a typhoon.SOLUTION: The method includes the steps of: constructing an actual typhoon wind field and a raindrop source at the top of a ground surface layer; simulating, on the basis of the actual typhoon wind field and the raindrop source at the top of the ground surface layer, a motion state of raindrops, and a process of collision and merger and collision and crush of raindrops, by using CFD simulation; and introducing wind field information to collision and merger cores and collision and crush cores of raindrops, and re-fitting a crushed raindrop spectrum formed after the collision and crush. Since the motion state and collision result of large-scale liquid particles at a high altitude in the actual typhoon wind field can be acquired, the problem of the prior art can be solved in which significant deviation occurs in precipitation simulation because the horizontal movement speed of the particles is not taken into consideration.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the field of meteorology and climate technology, and in particular to a method and system for calculating the motion and collision results of raindrops in a typhoon wind field. [Background technology]

[0002] Raindrop settling and collision / coalescence / fragmentation are important cloud microphysical processes that change the raindrop spectrum and affect precipitation. Due to changes in the land surface or topographical undulations, strong horizontal wind vertical shear and multi-scale turbulence occur near the ground during typhoon landfall, which affect the motion of raindrops and the outcome of collisions between raindrops.

[0003] The proposed cloud microphysics parameterization in a numerical weather prediction model predicts the location, duration, and intensity of surface precipitation by characterizing the production and loss of water molecules and the interconversion between different water molecules. The proposed stepwise cloud microphysics parameterization explicitly solves the merger / fragmentation nuclei of raindrops of different sizes to calculate the change in the number of raindrops within each step caused by collisions. The merger / fragmentation nuclei of two raindrops are equal to the product of the collection nuclei and the merger / fragmentation rate. Whether two raindrops merge or fragment after colliding depends on the magnitude of the kinetic energy CKE and the surface energy SE of the droplets at the time of collision. If the kinetic energy of the two raindrops at the time of collision is smaller (larger) than the surface energy of the droplets, coalescence (fragmentation) occurs.

[0004] CKE is related to the size of the two raindrops, their relative velocity at the time of collision, and the collision angle. When a raindrop starts falling from rest in a windless condition, its acceleration is affected only by gravity and drag. Drag is related to the scale of the raindrop and its own velocity. As the velocity of the raindrop gradually increases, drag gradually increases, and when its value becomes equal to gravity, the raindrop reaches a terminal velocity V g In windless conditions, raindrops quickly reach V g Therefore, in the stepwise cloud microphysics proposal, V g directly used to parameterize raindrop settling, and V gHowever, as can be seen from actual observations, the falling speed of raindrops near the surface layer of a landfalling typhoon, V v V g In many cases, the horizontal velocity of raindrops (V h ) cannot be ignored. Therefore, to calculate the relative velocity of two raindrops, it is necessary to use the total velocity of each. In addition, in the stepwise cloud microphysics proposal, the construction of the fragmented water droplet spectrum formed after the raindrops collide and fragment, is also based on the fact that two raindrops are V g This is based on experimental results or numerical simulation results observed after impact when the temperature reaches 1000 K. It does not take into account the effects of strong horizontal wind vertical shear and multi-scale turbulence on the fragmentation droplet spectrum formed by the impact. Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the deficiencies of the prior art, the present invention provides a method and system for calculating the motion state and collision results of raindrops in a typhoon wind field. [Means for solving the problem]

[0006] To achieve the above-mentioned objectives, in a first aspect, the present invention provides a method for calculating the motion and collision results of raindrops in a typhoon wind field. The method includes the steps of: constructing an actual typhoon wind field and a raindrop source at the top of the surface layer; setting initial fields and boundary conditions based on the actual typhoon wind field and the raindrop source at the top of the surface layer; simulating the motion of raindrops and the processes of collision and coalescence and fragmentation between raindrops of different scales using computational fluid dynamics simulation; and introducing wind field information into the collision and fragmentation nuclei of raindrops and the fragmentation nuclei of collision and fragmentation based on the simulation results, and refitting the spectrum of fragmented raindrops formed after collision and fragmentation. The present invention can obtain the motion and collision results of large-scale liquid particles at high altitudes in an actual typhoon wind field, while solving the problems of the prior art, which only obtain the motion of particles at a single height near the surface layer, resulting in unreasonable parameterization of the raindrop settling process and significant deviations in precipitation simulations due to the lack of consideration of the horizontal movement velocity of particles.

[0007] Preferably, the raindrop source on top of the surface layer satisfies a gamma spectral distribution and the total number of raindrops satisfies the following relationship:

number

[0008] Preferably, the method for setting initial fields and boundary conditions based on the wind field of the actual typhoon and the raindrop source at the top of the surface layer, and using computational fluid dynamics simulation to determine the state of motion of raindrops and the processes of collision and coalescence and fragmentation between raindrops of different scales, comprises the steps of: setting initial fields and boundary conditions based on the wind field of the actual typhoon and the raindrop source at the top of the surface layer, and describing the interaction between raindrops and airflow using a gas-liquid multiphase flow model; and directly solving the N-S equation using a direct numerical simulation method to obtain the three-dimensional spatial distribution of raindrops under the influence of the typhoon wind field, and thereby simulating the state of motion of raindrops and the processes of collision and coalescence and fragmentation between raindrops of different scales.

[0009] Preferably, the N-S equation satisfies the following relationship:

number

[0010] Preferably, the density of the mixed fluid satisfies the following relationship: ρ=ρ 液 c+ρ 気 (1-c), where ρ is the density of the mixed fluid, and ρ 液 and ρ 気 are the densities of the liquid and gas, respectively, and c is a smooth interface function that describes the mutation of material properties at the gas-liquid interface.

[0011] Preferably, the kinematic viscosity of the mixed fluid satisfies the following relationship: μ=μ 液 c+μ気 (1-c), where μ is the kinematic viscosity of the mixed fluid, and μ 液 and μ 気 are the dynamic viscosities of the liquid and gas, respectively, and c is a smooth interface function that describes the mutation of material properties at the gas-liquid interface.

[0012] Preferably, the distribution function of the fragmented raindrop spectrum satisfies a superposition function of the first distribution function and the second distribution function, and the superposition function satisfies the following relationship:

number

number

[0013] Preferably, the first distribution function satisfies the following relationship:

number

[0014] Preferably, the second distribution function satisfies the following relationship:

number

number

number

[0015] As described above, the method according to the present invention has at least the following advantages:

[0016] The method according to the present invention can calculate and obtain the motion and collision results of large-scale liquid particles at high altitudes under actual typhoon conditions, thereby solving the problem that the conventional observation method can only obtain the motion state of particles at a single height in the surface layer.

[0017] By obtaining the motion state and collision results of raindrops in the wind field of an actual typhoon, the method of the present invention can solve the problems that the parameterization of the raindrop settling process in the conventional step-by-step cloud microphysics parameterization proposal of a numerical weather forecast model is unreasonable, and the parameterization of the collision-coalescence and collision-fragmentation processes is unreasonable due to the failure to take into account the horizontal movement speeds of particles at different scales, resulting in significant deviations in the precipitation simulation.

[0018] In a second aspect, the present invention provides a system for calculating the motion and collision results of raindrops in a typhoon wind field. The system uses the method for calculating the motion and collision results of raindrops in a typhoon wind field according to the present invention. The system includes: a data acquisition device for constructing an actual typhoon wind field and a raindrop source at the top of the ground surface; a data simulation device for setting initial fields and boundary conditions based on the actual typhoon wind field and the raindrop source at the top of the ground surface, simulating the motion of raindrops and the processes of collision and fragmentation between raindrops of different scales using computational fluid dynamics simulation; introducing wind field information into the collision and fragmentation nuclei of raindrops and the collision and fragmentation nuclei of collision and fragmentation based on the simulation results; a data storage device for storing data generated by the data simulation device; and a data output facility for outputting the motion and collision results of raindrops in the actual typhoon wind field. The system according to the present invention can stably execute the method for calculating the motion and collision results of raindrops in a typhoon wind field according to the present invention, and can improve the efficiency of obtaining the motion and collision results of large-scale liquid particles at high altitudes in an actual typhoon wind field. [Brief explanation of the drawings]

[0019] In order to clearly explain the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings that need to be used in the embodiments. The following drawings only illustrate some embodiments of the present invention, so they should not be considered as limiting the scope, and it should be understood that those skilled in the art can obtain other related drawings based on these drawings without any creative work. [Figure 1] FIG. 1 is a flow chart diagram illustrating a method for calculating the motion state and collision results of raindrops in a typhoon wind field according to an embodiment of the present invention. [Figure 2] 1 is a schematic diagram of the framework of a calculation system for the motion state and collision results of raindrops in a typhoon wind field according to an embodiment of the present invention; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] Specific embodiments of the present invention will be described in detail below. Please note that the embodiments described herein are merely illustrative and do not limit the present invention. In the following description, a large amount of specific details are described to provide a clear understanding of the present invention. However, it is apparent that those skilled in the art do not need to use these specific details to practice the present invention. In other embodiments, well-known circuits, software, or methods are not specifically described to avoid confusion with the present invention.

[0021] Throughout the specification, references to "one embodiment," "an embodiment," "one example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the present invention. Thus, the appearances of the phrases "in one embodiment," "in an embodiment," "one example," or "an example" in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, particular features, structures, or characteristics may be combined in any combination and / or subcombination in one or more embodiments or examples. Those skilled in the art will understand that any drawings provided herein are for illustrative purposes only and that the drawings are not necessarily drawn to scale.

[0022] It should be noted that in a preferred embodiment, unless otherwise stated, the same symbols or characters appearing in all other formulas have the same meaning and value.

[0023] In one preferred embodiment, the present invention provides a method for calculating the motion state and collision results of raindrops in a typhoon wind field, as shown in Figure 1. The method includes the following steps:

[0024] In step S1, the wind field of a real typhoon and the raindrop source at the top of the surface layer are constructed.

[0025] Specifically, in this example, an actual typhoon wind field was constructed using ultrasonic anemometers installed at heights of 10 meters, 40 meters, 160 meters, and 320 meters on a 356-meter-tall steel tower in Shenzhen. The ultrasonic anemometers used had a maximum output frequency of 0.1 Hz, and the data collection period was from August 23, 2017 to August 27, 2017, which corresponds to the landfall period of typhoons Hato and Pakar.

[0026] More specifically, this example uses dual-polarization radar detection data to construct the raindrop source at the top of the surface layer, where the distance between the top of the surface layer and the ground is 500 meters. The dual-polarization radar used is the S-band radar at Guangzhou Station, and the precipitation rate at the top of the surface layer is calculated using the Z-R relationship formula. Specifically, the Z-R relationship formula is as follows:

[0027] Z=147.28R 1.38 where Z is the radar reflectivity of the dual-polarized radar and R is the precipitation rate at the top of the surface layer.

[0028] In this embodiment, it is assumed that the raindrop spectrum satisfies the gamma spectrum, i.e., N(D)=N0D k e -λD where N(D) is the number of raindrops with diameter D, N0 is the total number of raindrops, and k and λ are the shape and intercept parameters, respectively.

[0029] In order to obtain the raindrop spectrum at the top of the surface layer and satisfy the precipitation rate R obtained by inverse analysis, it is necessary to introduce the relationship between the shape parameter k and the intercept parameter λ, as well as the calculation relationship for the raindrop fall velocity. The shape parameter k and the intercept parameter λ satisfy the following relationship:

[0030] k=-0.0201λ 2 +0.902λ-1.718 The falling speed of raindrops satisfies the following relationship:

[0031] v(D)=αD β Note that α and β are speed calculation parameters, α is 3.78 and β is 0.67.

[0032] According to the above-mentioned relational expression, the precipitation rate can satisfy the following relational expression.

[0033]

number

number

[0034] Furthermore, since the S-band radar can provide data once every six minutes, the raindrop source is a source that changes once every six minutes. Also, in other preferred embodiments, other methods can be used to obtain the actual typhoon wind field and the raindrop source at the top of the surface layer according to the actual situation.

[0035] In step S2, the initial field and boundary conditions are set based on the wind field of the actual typhoon and the raindrop source at the top of the surface layer, and computational fluid dynamics simulation is used to simulate the motion state of raindrops and the processes of collision and coalescence and collision and fragmentation between raindrops of different scales.

[0036] Specifically, S2 includes the following steps:

[0037] In step S21, the initial field and boundary conditions are set based on the wind field of the actual typhoon and the raindrop source at the top of the ground surface layer, and a gas-liquid multiphase flow model is used to describe the interaction between the raindrops and the airflow.

[0038] In step S22, the direct numerical simulation method is used to directly solve the N-S equation to obtain the three-dimensional spatial distribution of raindrops under the influence of the typhoon wind field, and then simulate the motion state of raindrops and the processes of collision and coalescence and collision and fragmentation between raindrops of different scales.

[0039] Specifically, in this embodiment, the computational fluid dynamics simulation is a CFD simulation, in which a gas-liquid multiphase model and a direct numerical simulation method are simultaneously used. Specifically, initial field and boundary conditions are set based on the actual typhoon wind field and the raindrop source at the top of the ground surface. The gas-liquid multiphase model is used to simulate the movement of raindrops in the actual typhoon wind field. The interaction between raindrops and airflow, such as resistance and buoyancy, is considered in the simulation process. DNS is used to solve the N-S equation to obtain the 3D spatial distribution of raindrops under the influence of the typhoon wind field. This then simulates the raindrop movement and the processes of raindrop collision and fragmentation at different scales under the actual typhoon wind field conditions, thereby obtaining the raindrop collision and fragmentation rate, collision and fragmentation rate, and raindrop spectrum after collision and fragmentation under the actual typhoon wind field conditions.

[0040] More specifically, the NS equation satisfies the following relationship:

number

[0041] where U is the velocity field, t is time, p is pressure, f is volume force, ρ and μ are the density and dynamic viscosity of the mixed fluid, respectively, and ρ 液 and ρ 気 are the densities of the liquid and gas, respectively, and μ液 and μ 気 are the kinematic viscosities of the liquid and gas, respectively, and c is a smooth interface function that describes the mutation of material properties at the gas-liquid interface. The density and kinematic viscosity of the mixed fluid satisfy the following relations, in turn: ρ=ρ 液 c+ρ 気 (1-c) μ=μ 液 c+μ 気 (1-c)

[0042] where ρ is the density of the mixed fluid, μ is the kinematic viscosity of the mixed fluid, and ρ 液 and ρ 気 are the densities of the liquid and gas, respectively, and μ 液 and μ 気 are the dynamic viscosities of the liquid and gas, respectively, and c is a smooth interface function that describes the mutation of material properties at the gas-liquid interface.

[0043] Furthermore, the rationality of the raindrop motion state and raindrop spectrum distribution obtained by the CFD simulation was verified by cross-validating the results of the CFD simulation with data collected by raindrop spectrometers installed at different heights on a 356-meter-tall steel tower in Shenzhen. Since this is a conventional technique, a detailed explanation will be omitted here.

[0044] Furthermore, the raindrop spectrometer used in this example is a laser raindrop spectrometer, which can classify raindrops into 32 scales based on their size, with each scale representing a range of the size of one specific raindrop. The minimum raindrop diameter that can be detected by the laser raindrop spectrometer used is 0.062 mm, and the maximum raindrop diameter is 24.5 mm. Quality control of the observation data from the laser raindrop spectrometer determines the number of raindrops that fall on the i-th scale, N(D i ) becomes:

number

[0045] In step S3, based on the simulation results, wind field information is introduced into the raindrop collision and coalescence nuclei and collision and fragmentation nuclei, and the fragmented raindrop spectrum formed after the collision and fragmentation is refitted.

[0046] Specifically, in this embodiment, the CFD simulation in step S2 can obtain the raindrop motion state, collision and coalescence rate, collision and fragmentation rate, and raindrop spectrum distribution after collision and fragmentation. However, although the initial field can be set in the CFD simulation process, the wind field may change during the simulation process. These changes may affect the raindrop motion trajectory, speed, collision and fragmentation processes. Therefore, it is necessary to introduce wind field information into the raindrop collision and fragmentation cores and collision and fragmentation cores, and refit the fragmented raindrop spectrum formed after the collision and fragmentation.

[0047] More specifically, the CFD simulation process can obtain the actual moving speed of raindrops and calculate the relative speed between raindrops to fit a functional relationship between the collision kinetic energy of raindrops and the coalescence rate or fragmentation rate of raindrops when they collide. The raindrop fragmentation spectrum is fitted by taking a large number of collision fragmentation event samples to determine the formation of fragmented raindrops of different scales after the collision of raindrops of different scales. Since the collision kinetic energy is also used in the raindrop fragmentation spectrum calculation process, the particle movement speed is also used in the spectrum calculation of the raindrop fragmentation spectrum. The relationship between wind field - particle movement speed - collision kinetic energy - collision coalescence / fragmentation rate and raindrop fragmentation spectrum is indirectly established.

[0048] Furthermore, by considering the influence of wind fields on the raindrop fragmentation process and the distribution of raindrop spectra, the accuracy of the obtained raindrop motion state and collision results can be improved, which will contribute to more accurate prediction of parameters such as rainfall intensity, distribution, and type, and provide more reliable data support for fields such as weather forecasting and water resource management.

[0049] Furthermore, the spectrum of broken raindrops is usually a superposition of multiple distribution functions, specifically, a superposition function of a first distribution function and a second distribution function. The first distribution function is a log-normal distribution function, and the second distribution function is a normal distribution function. The first distribution function, the second distribution function, and the superposition function of the two satisfy the following relationship in order, with the diameter of the raindrop as a variable:

number

number

number

[0050] It should be noted that in some cases, the actions described in the specification can be performed in a different order and still achieve the desired results. In the examples, the order of the steps given is merely for clarity and ease of explanation of the examples, and is not a limitation of the examples.

[0051] In one preferred embodiment, the present invention provides a system for calculating the motion and collision results of raindrops in a typhoon wind field, as shown in Figure 2. The system uses the method for calculating the motion and collision results of raindrops in a typhoon wind field according to the present invention. The system includes a data acquisition device A1, a data simulation device A2, a data storage device A3, and a data output facility A4.

[0052] The data acquisition device A1 is used to construct the wind field of a real typhoon and the raindrop source on top of the surface layer.

[0053] Specifically, in this embodiment, the data acquisition device A1 is equipped with an ultrasonic anemometer and a dual-polarized radar, and uses the ultrasonic anemometer to construct an actual typhoon wind field and the detection data of the dual-polarized radar to construct the raindrop source at the top of the ground surface layer. Specifically, the data acquisition device A1 executes the contents described in step S1.

[0054] In another preferred embodiment, the data acquisition device A1 may further comprise a raindrop spectrometer.

[0055] The data simulation device A2 sets initial fields and boundary conditions based on the wind field of the actual typhoon and the raindrop source at the top of the surface layer, and uses computational fluid dynamics simulation to simulate the motion state of raindrops and the processes of collision and coalescence and collision and fragmentation between raindrops of different scales. Based on the motion state of raindrops, collision and coalescence rate, collision and fragmentation rate, and the distribution of the raindrop spectra after the collision and fragmentation, wind field information is introduced into the collision and coalescence cores and collision and fragmentation cores of raindrops, and the fragmented raindrop spectra formed after the collision and fragmentation are re-fitted.

[0056] Specifically, in this embodiment, the data simulation device A2 is electrically connected to the data acquisition device A1. Specifically, the data simulation device A2 executes the contents described in steps S2 and S3.

[0057] The data storage device A3 is used to store the data generated by the data simulation device A2.

[0058] Specifically, in this embodiment, the data storage device A3 is electrically connected to the data simulation device A2. The data stored in the data storage device A3 includes the raindrop motion state, the collision and merger rate, the collision and fragmentation rate, and the raindrop spectrum distribution after collision and fragmentation.

[0059] The data output device A4 is used to output the motion and collision results of raindrops in the wind field of an actual typhoon.

[0060] Specifically, in this embodiment, the data output device A4 is electrically connected to the data storage device A3, and includes at least one digital display for displaying the motion and collision results of raindrops in the actual typhoon wind field.

[0061] As described above, the method of the present invention can calculate and obtain the motion and collision results of large-scale liquid particles at high altitudes under actual typhoon conditions, thereby solving the problem of conventional observation methods only being able to obtain the motion of particles at a single height in the ground surface layer. Furthermore, by obtaining the motion and collision results of raindrops in an actual typhoon wind field, the method of the present invention can solve the problems of conventional scaled cloud microphysics parameterization schemes for numerical weather forecasting models, such as the irrational parameterization of the raindrop settling process and the irrational parameterization of the collision-coalescence and collision-fragmentation processes caused by not taking into account the horizontal movement velocities of particles at different scales, resulting in significant deviations in precipitation simulations. Furthermore, the system of the present invention can stably execute the method of calculating the motion and collision results of raindrops in a typhoon wind field, thereby improving the efficiency of obtaining the motion and collision results of large-scale liquid particles at high altitudes in an actual typhoon wind field.

[0062] Finally, it should be noted that the above-described embodiments are merely illustrative of the technical solutions of the present invention and do not limit the present invention. Although the present invention has been described in detail with reference to the above-described embodiments, it should be understood that those skilled in the art may modify the technical solutions described in the above-described embodiments or make equivalent substitutions for some or all of the technical features thereof. Such modifications or substitutions do not deviate from the essence of the corresponding technical solutions from the scope of the technical solutions of the respective embodiments of the present invention, and all fall within the scope of the claims and description of the present invention.

Claims

1. constructing a real typhoon wind field and raindrop source on top of the surface layer; Setting initial fields and boundary conditions based on the wind field of the actual typhoon and the raindrop source at the top of the surface layer, and simulating the motion state of raindrops and the processes of collision and coalescence and collision and fragmentation between raindrops of different scales using a computational fluid dynamics simulation; A method for calculating the motion state and collision results of raindrops in a typhoon wind field, characterized by comprising a step of introducing wind field information into the raindrop collision and coalescence nuclei and collision and fragmentation nuclei based on the simulation results, and refitting the fragmented raindrop spectrum formed after the collision and fragmentation.

2. The raindrop source on top of the surface layer satisfies a gamma spectral distribution, and the total number of raindrops satisfies the following relationship: [Equation 1] In addition, N ０ 2. The method for calculating the motion state and collision results of raindrops in a typhoon wind field according to claim 1, wherein: σ is the total number of raindrops, R is the precipitation rate at the top of the surface layer, k is a shape parameter, α and β are velocity calculation parameters, λ is an intercept parameter, ρ is a density parameter, and Γ(·) represents the formula of the gamma function.

3. The step of setting initial fields and boundary conditions based on the wind field of the actual typhoon and the raindrop source at the top of the surface layer, and simulating the motion state of raindrops and the processes of collision and coalescence and collision and fragmentation between raindrops of different scales using a computational fluid dynamics simulation, setting initial fields and boundary conditions based on the wind field of the actual typhoon and the raindrop source at the top of the surface layer, and describing the interaction between the raindrops and the airflow using a gas-liquid multiphase flow model; The method for calculating the motion state and collision results of raindrops in a typhoon wind field according to claim 1, further comprising the steps of: directly solving the N-S equation using a direct numerical simulation method to obtain the three-dimensional spatial distribution of raindrops under the influence of the typhoon wind field; and simulating the motion state of raindrops and the process of collision, coalescence, and collision fragmentation between raindrops of different scales.

4. The N-S equation satisfies the following relationship: [Equation 2] where U is the velocity field, t is time, p is pressure, f is volume force, ρ and μ are the density and dynamic viscosity of the mixed fluid, respectively, and ρ 液 and ρ 気 are the densities of the liquid and gas, respectively, and μ 液 and μ 気 The method for calculating the motion state and collision results of raindrops in a typhoon wind field according to claim 3, characterized in that σ is the dynamic viscosity of the liquid and the gas, respectively, and c is a smooth interface function that describes the mutation of material properties at the gas-liquid interface.

5. The density of the mixed fluid satisfies the following relationship: p=p 液 c+r 気 (1-a) where ρ is the density of the mixed fluid, and ρ 液 and ρ 気 The method for calculating the motion state and collision results of raindrops in a typhoon wind field according to claim 4, characterized in that ρ and ρ are the densities of the liquid and gas, respectively, and c is a smooth interface function that describes the mutation of material properties at the gas-liquid interface.

6. The kinematic viscosity of the mixed fluid satisfies the following relationship: μ=μ 液 c+μ 気 (1-a) where μ is the kinematic viscosity of the mixed fluid, and μ 液 and μ 気 The method for calculating the motion state and collision results of raindrops in a typhoon wind field according to claim 4, characterized in that σ and σ are the dynamic viscosities of the liquid and gas, respectively, and c is a smooth interface function that describes the mutation of material properties at the gas-liquid interface.

7. The distribution function of the broken raindrop spectrum satisfies a superposition function of the first distribution function and the second distribution function, and the superposition function satisfies the following relationship: [Equation 3] In addition, P ａｌｌ (D) is the number of raindrops of diameter D produced by breakup, P(D) is the number of raindrops of diameter D after breakup occurs, and the distribution of raindrops of each scale size produced by breakup satisfies a first distribution function, [Equation 4] is the number of raindrops with diameter D after fragmentation occurs, and the distribution of raindrops of each scale size formed by fragmentation satisfies a second distribution function.

8. The first distribution function satisfies the following relationship: [Equation 5] where p(D) is the probability density function of the log-normal distribution, D is the diameter of the raindrop, and σ １ is the standard deviation of the logarithm of the variable, and μ １ is the average value of the logarithm of the variable, P(D) is the number of raindrops with diameter D after fragmentation occurs, the distribution of raindrops of each scale size formed by fragmentation satisfies a first distribution function, N is the total number of raindrops formed after fragmentation occurs, Var is the variance of the logarithm of the variable, E is the expected value of the logarithm of the variable, and ΔD is the perturbation amount of D. The method for calculating the motion state and collision results of raindrops in a typhoon wind field described in claim 7.

9. The second distribution function satisfies the following relationship: [Equation 6] In addition, [Equation 7] is the probability density function of the normal distribution function, D is the diameter of the raindrop, [Equation 8] is the number of raindrops of diameter D after the breakup occurs, and the distribution of raindrops of each scale size formed by the breakup satisfies the second distribution function, σ ２ is the standard deviation of the variable, and μ ２ 8. The method for calculating the motion state and collision results of raindrops in a typhoon wind field according to claim 7, characterized in that ΔD is the average value of the variable, ΔD is the perturbation amount of D, and N is the total number of raindrops formed after the breakup occurs.

10. A calculation system for the motion state and collision results of raindrops in a typhoon wind field using the calculation method for the motion state and collision results of raindrops in a typhoon wind field according to any one of claims 1 to 9, A data acquisition device used to construct the actual typhoon wind field and raindrop source on top of the surface layer; A data simulation device that sets initial field and boundary conditions based on the wind field of the actual typhoon and the raindrop source at the top of the surface layer, simulates the motion state of raindrops and the processes of collision and coalescence and collision and fragmentation between raindrops of different scales using a computational fluid dynamics simulation, introduces wind field information into the collision and coalescence cores and collision and fragmentation cores of raindrops based on the simulation results, and refits the fragmented raindrop spectrum formed after the collision and fragmentation; a data storage device used to store data generated by the data simulation device; A calculation system for the movement state and collision results of raindrops in a typhoon wind field, characterized by comprising: a data output facility used to output the movement state and collision results of raindrops in an actual typhoon wind field.

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