Method, device, equipment and medium for determining flame morphology based on numerical simulation

Abstract

The present invention relates to a method, device, equipment and medium for determining flame morphology based on numerical simulation, the method comprising: determining a calculation area in a fire numerical simulation process, wherein the calculation area includes a plurality of first grids, and the flame morphology includes flame surface area, flame height, volume and force; determining the flame surface area in the calculation area based on the temperature of each first grid; determining a grid set of the flame surface area, and determining the flame height based on the ordinate of the second grid in the grid set; determining the flame volume in the calculation area based on the chemical reaction rate of each first grid; and calculating the flame force based on the flame surface area and the flame volume. The present invention can make up for the deficiencies in quantifying flame morphological characteristics in fire numerical simulation.

Description

Technical Field

[0001] The present invention relates to the field of numerical simulation technology, and in particular to a method, device, equipment and medium for determining flame morphology based on numerical simulation. Background Art

[0002] Fire is a combustion that is out of control in time or space. It is one of the most frequent and common disasters that threaten public safety and social development. In the process of fire, in addition to the damage caused by hot smoke to people, the flame can also cause damage to people and buildings. The shape, height, tilt angle, and pulsation frequency of the flame are important parameters of the flame morphology. Real-time quantification of the above parameters and force analysis of the flame are of great significance to the study of flame morphology.

[0003] Experiments, numerical simulations and theoretical analysis are the main research methods in fire research. Although experiments are the most reliable, the research cycle is long and the types of physical quantities that can be measured are limited; theoretical analysis can only provide analytical solutions under certain special circumstances, or provide the change laws of certain physical quantities in space or time under the premise of a large number of simplifications; numerical simulation has low cost, short cycle, and is easy to carry out parameter analysis. It can reflect the process of fire occurrence and development to a certain extent, and is an important technology in fire research.

[0004] Fire numerical simulation is a numerical simulation technology used in fire science to study the occurrence and development of fire. Currently, the commonly used fire numerical simulation software includes FDS (Fire Dynamic Simulator) and FLUENT. These software can give relatively reasonable results in calculating the flow characteristics of fire smoke and temperature field changes, but currently these software cannot give accurate flame shapes, real-time flame surface position, flame height and pulsation frequency, nor can they quantify the force exerted on the flame, so they cannot predict or explain the reasons for the flame tilt. Summary of the invention

[0005] In view of this, it is necessary to provide a method, device, equipment and medium for determining flame morphology based on numerical simulation, so as to solve the shortcomings of current fire numerical simulation in predicting and quantifying flame morphology characteristics.

[0006] In order to solve the above problems, in a first aspect, the present invention provides a method for determining flame morphology based on numerical simulation, comprising:

[0007] Determine a calculation area in the fire numerical simulation process, wherein the calculation area includes a plurality of first grids, the flame shape includes a flame surface area, a flame height, a volume and a force, wherein the first grid is a grid corresponding to the calculation area of ​​the fire numerical simulation process;

[0008] determining a flame face region in the calculation region based on the temperature and the fuel concentration of each first grid;

[0009] Determine a grid set of the flame surface area, and determine the flame height based on the ordinate of a second grid in the grid set;

[0010] determining a flame volume in the calculation region based on a chemical reaction rate of each first grid;

[0011] The flame force is calculated based on the flame surface area and the flame volume.

[0012] Further, the determining of the flame surface area in the calculation area based on the temperature and fuel concentration of each first grid includes:

[0013] Determine the fuel concentration of each first grid, calculate the fuel concentration gradient value of each first grid based on the fuel concentration of each first grid, and if the fuel concentration gradient value of any first grid is infinite, confirm the first grid as a third grid, wherein the third grid is a grid in the first grid whose fuel concentration gradient value is infinite;

[0014] The temperature of each third grid is determined. If the temperature of any third grid is greater than the fuel ignition point, the third grid is confirmed as the second grid, and the area of ​​the second grid in the calculation area is determined as the flame surface area, wherein the second grid is a grid in the third grid whose temperature is greater than the fuel ignition point.

[0015] Further, the determining the flame height based on the ordinate of the second grid in the grid set includes:

[0016] The maximum value of the ordinate in the second grid is determined, and the maximum value is determined as the maximum flame height.

[0017] Further, the determining of the flame volume in the calculation region based on the chemical reaction rate of each first grid includes:

[0018] Based on the chemical reaction rate of each first grid, a fourth grid in the calculation area is determined, and the volume of the fourth grid is summed to obtain the flame volume, wherein the fourth grid is a grid whose chemical reaction rate is not zero in the first grid.

[0019] Furthermore, the chemical reaction rate of the first grid is determined based on the vortex combustion model, and the expression of the chemical reaction rate is:

[0020]

[0021] Where ρ is the fluid density in the first grid, k is the turbulent kinetic energy, ε is the turbulent kinetic energy dissipation rate, and Y ris the mass fraction of any reactant in the grid, Y p is the mass fraction of any product in the grid, p is the product, v″ r is the stoichiometric number of reactants in the chemical reaction equation, v″ j is the stoichiometric number of the product in the chemical reaction equation, m is the total number of reactants, M w,r is the molar mass of the product, M w,j is the molar mass of the reactant, and A and B are constants.

[0022] Furthermore, the flame force includes the flame force and the flame force components in different directions, wherein the flame force components in different directions include:

[0023]

[0024]

[0025]

[0026] Among them, f x 、f y and f z are the components of the flame on the x-axis, y-axis and z-axis respectively, and are the accelerations of the flame on the x-axis, y-axis and z-axis respectively, n is the number of grids in the second grid, ρ i is the fluid density of the i-th grid constituting the flame surface, δV i is the grid volume of the i-th grid constituting the flame surface, and are the accelerations of the fluid in the i-th grid that constitutes the flame surface.

[0027] Furthermore, the flame shape also includes a flame pulsation frequency, and determining the flame pulsation frequency includes:

[0028] Determining a fifth grid located in the intermittent flame area in the grid set of the flame surface area, wherein the flame surface area includes a continuous flame area, an intermittent flame area, and a buoyancy plume area;

[0029] Obtaining a curve of a chemical reaction rate changing over time in the fifth grid, and obtaining a flame pulsation period based on the curve;

[0030] The flame pulsation period is calculated inversely to obtain the flame pulsation frequency.

[0031] In a second aspect, the present invention also provides a device for determining flame morphology based on numerical simulation, comprising:

[0032] A calculation region determination module, used to determine a calculation region in a fire numerical simulation process, wherein the calculation region includes a plurality of first grids, and the flame shape includes a flame surface area, a flame height, a volume, and a force;

[0033] a flame surface region determination module, for determining the flame surface region in the calculation region based on the temperature and fuel concentration of each first grid;

[0034] A flame height determination module, used to determine a grid set of a flame surface area, and determine the flame height based on the ordinate of a second grid in the grid set;

[0035] a flame volume determination module, configured to determine the flame volume in the calculation area based on the chemical reaction rate of each first grid;

[0036] The flame force calculation module is used to calculate the flame force based on the flame surface area and the flame volume.

[0037] In a third aspect, the present invention further provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps in the above-mentioned method for determining flame morphology based on numerical simulation are implemented.

[0038] In a fourth aspect, the present invention further provides a computer storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps in the method for determining flame morphology based on numerical simulation as described above are implemented.

[0039] The beneficial effects of adopting the above embodiment are:

[0040] The present invention determines the flame surface area by using the grid temperature in the calculation area during the fire numerical simulation process, determines the flame height according to the ordinate of the flame surface area grid set, determines the flame volume in the calculation area based on the chemical reaction rate of each first grid, and finally calculates the flame force based on the flame surface area and the flame volume. In the fire numerical simulation process, the accurate flame surface is captured, the flame height and the flame volume are calculated, the force on the flame is analyzed, the flame morphology changes are explained, and the deficiencies in the quantitative flame morphology characteristics are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic diagram of a flow chart of an embodiment of a method for determining flame morphology based on numerical simulation provided by the present invention;

[0042] Figure 2 A flame schematic diagram provided for an embodiment of the present invention.

[0043] Figure 3A schematic diagram of fuel concentration distribution characteristics provided by an embodiment of the present invention;

[0044] Figure 4 A schematic diagram of a flame height calculation method provided by an embodiment of the present invention;

[0045] Figure 5 A schematic diagram of a flame tilting under the action of wind provided in one embodiment of the present invention;

[0046] Figure 6 A schematic diagram of a curve showing a chemical reaction rate variation over time in the fifth grid of an intermittent flame zone provided by an embodiment of the present invention;

[0047] Figure 7 A schematic structural diagram of an embodiment of a device for determining flame morphology based on numerical simulation provided by the present invention;

[0048] Figure 8 A schematic structural diagram of an embodiment of an electronic device provided by the present invention. DETAILED DESCRIPTION

[0049] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0050] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. Reference to "embodiments" in this article means that the specific features, structures or characteristics described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0051] The specific embodiments are described in detail below:

[0052] See also Figure 1 , Figure 1 A flow chart of an embodiment of a method for determining flame morphology based on numerical simulation provided by the present invention is provided. A specific embodiment of the present invention discloses a method for determining flame morphology based on numerical simulation, comprising:

[0053] Step S101: determining a calculation area in a fire numerical simulation process, wherein the calculation area includes a plurality of first grids, and the flame shape includes a flame surface area, a flame height, a volume, and a force, wherein the first grid is a grid corresponding to the calculation area of ​​the fire numerical simulation process;

[0054] Step S102: determining a flame surface area in a calculation area based on the temperature and fuel concentration of each first grid;

[0055] Step S103: determining a grid set of the flame surface area, and determining the flame height based on the ordinate of the second grid in the grid set;

[0056] Step S104: determining a flame volume in a calculation region based on a chemical reaction rate of each first grid;

[0057] Step S105: Calculate flame force based on the flame surface area and flame volume.

[0058] The present invention determines the flame surface area by using the grid temperature in the calculation area during the fire numerical simulation process, determines the flame height according to the ordinate of the flame surface area grid set, determines the flame volume in the calculation area based on the chemical reaction rate of each first grid, and finally calculates the flame force based on the flame surface area and the flame volume. In the fire numerical simulation process, the accurate flame surface is captured, the flame height and the flame volume are calculated, the force on the flame is analyzed, the flame morphology changes are explained, and the deficiencies in the quantitative flame morphology characteristics are improved.

[0059] In one embodiment of the present invention, determining the flame surface area in the calculation area based on the temperature and fuel concentration of each first grid includes:

[0060] Determine the fuel concentration of each first grid, calculate the fuel concentration gradient value of each first grid based on the fuel concentration of each first grid, if the fuel concentration gradient value of any first grid is infinite, confirm the first grid as a third grid, wherein the third grid is a grid in the first grid whose fuel concentration gradient value is infinite;

[0061] The temperature of each third grid is determined. If the temperature of any third grid is greater than the fuel ignition point, the third grid is confirmed as the second grid, and the area of ​​the second grid in the calculation area is determined as the flame surface area, wherein the second grid is a grid in the third grid whose temperature is greater than the fuel ignition point.

[0062] It is understandable that the area where the flame exists is the area where the chemical reaction occurs, and vice versa. On the surface of the flame, air containing oxygen is sucked into the flame and a chemical reaction occurs at the same time. The oxygen that does not participate in the reaction continues to diffuse into the flame under the action of Fick's law and reacts chemically with the fuel inside. Figure 2 As shown, Figure 2 A flame schematic diagram provided for an embodiment of the present invention.

[0063] For fuel, if the temperature is above the ignition point of the fuel and there is oxygen, combustion can occur. Therefore, on the flame surface, the concentration of the fuel changes suddenly: that is, when the flame surface faces outward, if the temperature inside the grid is above the ignition point of the fuel, there is no fuel and the fuel mass fraction is 0; when the flame surface faces inward, there is fuel and the fuel mass fraction is not 0.

[0064] like Figure 3 As shown, Figure 3 A schematic diagram of fuel concentration distribution characteristics provided by an embodiment of the present invention. Therefore, in the process of determining the flame surface area in the calculation area based on the temperature and fuel concentration of the first grid, it is necessary to first determine the fuel concentration of each first grid, and if the fuel concentration of any first grid is greater than the preset concentration value, the first grid is confirmed as the third grid.

[0065] In one embodiment of the present invention, the fuel concentration gradient value of each first grid is calculated. If the fuel concentration gradient value of any first grid is infinite, the first grid is confirmed as the third grid, that is, the third grid is the grid in the first grid whose fuel concentration gradient value is infinite.

[0066] Specifically, by finding the gradient of the fuel concentration field in the calculation area, the grid with the fuel gradient field marked as infinite is the third grid, that is, the probability of flame appearing in the third grid is higher. However, not all grids with infinite fuel concentration gradient will have flames, because there may be air masses of unburned gas above the flames. Although the grids where the surfaces of these unburned gas masses are located also meet the characteristics of the maximum fuel concentration gradient, they are not burning, so no flames appear. The difference between the third grid and the grid where the flame is located, that is, the second grid, is whether the temperature in the grid has reached the ignition point of the combustible vapor, among which the second grid is the grid in the third grid whose temperature is greater than the ignition point of the fuel.

[0067] Therefore, the method to distinguish the third grid from the grid with flames is to judge the temperature in the third grid. If the grid temperature is greater than the fuel ignition point, it is considered to be a grid on the flame surface; otherwise, it is a grid containing unburned fuel and the mark is cancelled. At this point, the surface composed of all marked grids is the flame surface.

[0068] In one embodiment of the present invention, determining the flame height based on the ordinate of the second grid in the grid set includes:

[0069] The maximum value of the ordinate in the second grid is determined, and the maximum value is determined as the maximum flame height.

[0070] It can be understood that, if all the second grids in the calculation area are determined as a set S, then the maximum value of the ordinates of all the grids in the set S is the flame height H, which can be expressed as: H = max{z i,S}, i = 1, 2, 3, ..., n. Where S is the grid set that makes up the flame surface, n is the number of elements in S, z i,S is the ordinate of grid i in S. With the flame height H, the average flame height can be calculated and maximum flame height H max .like Figure 4 shown. Figure 4 A schematic diagram of a flame height calculation method provided by an embodiment of the present invention. Refers to the H value corresponding to the intermittent rate I of 0.5, the maximum flame height H max It is the H value corresponding to the intermittent rate I approaching 0.

[0071] In one embodiment of the present invention, determining the flame volume in the calculation region based on the chemical reaction rate of each first grid includes:

[0072] The fourth grid in the calculation area is determined based on the chemical reaction rate of each first grid, and the volume of the fourth grid is summed up to obtain the flame volume, wherein the fourth grid is a grid whose chemical reaction rate is not zero in the first grid.

[0073] It can be understood that after obtaining the grid set S that constitutes the flame surface, if the flame volume is to be calculated, it is necessary to obtain the grid set that constitutes the flame volume, which is recorded as set T. The elements in set T are the grids that constitute the flame, which can be specifically determined by judging the grid (x i ,y i ,z i ) is equal to 0 to determine whether the grid is located in the flame area, that is, for grid i, if the chemical reaction rate in grid i is 0, then grid i is not in the flame area, if the chemical reaction rate in grid i is not 0, then grid i is in the flame area. That is, the fourth grid is the grid whose chemical reaction rate in the first grid is not zero. Further, the volume of the flame can be obtained by summing the volumes of all grids located in the flame area: Among them, δV j is the volume of the jth grid in the set T, and n is the number of elements in the set T.

[0074] It is understandable that the reaction rate can be calculated by the combustion model. In the numerical simulation of fire, the eddy dissipation model can be used. In one embodiment of the present invention, the expression for determining the chemical reaction rate of the first grid based on the eddy dissipation combustion model is:

[0075]

[0076] Where ρ is the fluid density in the first grid, k is the turbulent kinetic energy, ε is the turbulent kinetic energy dissipation rate, and Y r is the mass fraction of any reactant in the grid, Y p is the mass fraction of any product in the grid, p is the product, v″ r is the stoichiometric number of reactants in the chemical reaction equation, v″ j is the stoichiometric number of the product in the chemical reaction equation, m is the total number of reactants, M w,r is the molar mass of the product, M w,j is the molar mass of the reactant, A and B are constants, and A is 4.0 and B is 0.5.

[0077] It is understandable that the tilt and other characteristics of the flame are controlled by the surface forces acting on the flame. Quantifying the forces acting on the flame can easily predict the tilt of the flame. Figure 5 As shown, Figure 5 The figure is a schematic diagram of the inclination of a flame under the action of wind provided in one embodiment of the present invention. If the force on the flame is solved, we have

[0078]

[0079] in, is the force on the flame, which is a vector and can be expressed as (f x ,f y ,f z ). The surface integral is converted into volume integral by Gaussian divergence theorem, so as to calculate the resultant force on the flame. The resultant force can only give the magnitude of the force on the flame surface, but cannot reflect the direction of the force. Therefore, the resultant force on the flame surface in three directions should be considered.

[0080] In one embodiment of the present invention, the components of the flame in different directions include:

[0081]

[0082]

[0083]

[0084] Among them, f x 、f y and f z are the components of the flame on the x-axis, y-axis and z-axis respectively, and are the accelerations of the flame on the x-axis, y-axis and z-axis respectively, n is the number of grids in the second grid, ρ i is the fluid density of the i-th grid constituting the flame surface, δV iis the grid volume of the i-th grid constituting the flame surface, and are the accelerations of the fluid in the i-th grid that constitutes the flame surface.

[0085] In one embodiment of the present invention, the flame shape further includes a flame pulsation frequency, and determining the flame pulsation frequency includes:

[0086] Determining a fifth grid located in the intermittent flame region from the grid set in the flame surface region, wherein the flame surface region includes a continuous flame region, an intermittent flame region, and a buoyancy plume region;

[0087] Obtaining a curve of a chemical reaction rate changing with time in the fifth grid, and obtaining a flame pulsation period based on the curve;

[0088] The flame pulsation period is calculated inversely to obtain the flame pulsation frequency.

[0089] It is understandable that flame pulsation is an important feature that distinguishes flames from other luminous objects, such as fluorescent lamps, and can be used in image recognition to distinguish whether the object to be tested is a fire source. At present, the calculation of flame pulsation frequency is obtained by processing the flame image measured in the experiment. The general process is: flame image acquisition, image binarization, similarity calculation, Fourier transform and the process of obtaining the flame pulsation frequency. In numerical simulation, since it is very convenient to obtain the data in each grid: such as reaction rate, temperature, speed and other physical quantities, the flame pulsation frequency can be extracted based on the data in the numerical simulation.

[0090] Specifically, the time period for calculating the flame pulsation frequency should be selected, and the duration of this time period should be greater than the flame pulsation frequency. The flame pulsation frequency is related to the diameter of the fire source, and the relationship can be expressed as: f = 1.68D -0.5 , where f is the estimated flame pulsation frequency and D is the flame diameter. A suitable time period is selected through the above formula, and the duration of the time period should be greater than the period of flame pulsation. For example, if the estimated period of flame pulsation is 1s, the duration of the time period can be 10s.

[0091] The flame can be divided into the continuous flame zone, the intermittent flame zone and the buoyancy plume zone. Then find the fifth grid located in the intermittent flame zone. The fifth grid is characterized by the existence of periodic oscillating flames, that is, flames appear in a certain period of time, and no flames exist in the next period of time, and so on. Reflected in the numerical simulation, the characteristic of this grid is that the chemical reaction rate shows periodic changes: it is 0 for a period of time, and it is not 0 again in the next period of time, and so on. Therefore, the chemical reaction rate in this grid can be plotted as a function of time, such as Figure 6 As shown, Figure 6A schematic diagram of a curve of a chemical reaction rate changing with time in the fifth grid of an intermittent flame zone provided by an embodiment of the present invention. The figure shows the length of the pulsation period within the selected time. The pulsation period is the sum of the time when the chemical reaction rate is 0 plus the time when the chemical reaction rate is not 0. The inverse of the pulsation period is the pulsation frequency of the flame.

[0092] In order to better implement the method for determining flame morphology based on numerical simulation in the embodiment of the present invention, based on the method for determining flame morphology based on numerical simulation, correspondingly, please refer to Figure 7 , Figure 7 This is a schematic diagram of the structure of an embodiment of a device for determining flame morphology based on numerical simulation provided by the present invention. The embodiment of the present invention provides a device 700 for determining flame morphology based on numerical simulation, including:

[0093] The calculation region determination module 701 is used to determine the calculation region in the fire numerical simulation process, wherein the calculation region includes a plurality of first grids, and the flame shape includes the flame surface area, flame height, volume and force;

[0094] A flame surface region determination module 702, for determining a flame surface region in a calculation region based on the temperature and fuel concentration of each first grid;

[0095] The flame height determination module 703 is used to determine a grid set of the flame surface area and determine the flame height based on the ordinate of the second grid in the grid set;

[0096] A flame volume determination module 704, for determining a flame volume in a calculation region based on a chemical reaction rate of each first grid;

[0097] The flame force calculation module 705 is used to calculate the flame force based on the flame surface area and the flame volume.

[0098] It should be noted here that: the device 700 provided in the above embodiment can implement the technical solutions described in the above method embodiments. The specific implementation principles of the above modules or units can refer to the corresponding contents in the above method embodiments, which will not be repeated here.

[0099] Based on the above-mentioned method for determining flame morphology based on numerical simulation, an embodiment of the present invention also provides an electronic device accordingly, including: a processor and a memory, and a computer program stored in the memory and executable on the processor; when the processor executes the computer program, the steps in the method for determining flame morphology based on numerical simulation in the above-mentioned embodiments are implemented.

[0100] Figure 88 is a schematic diagram of the structure of an electronic device 800 suitable for implementing the embodiment of the present invention. The electronic device in the embodiment of the present invention may include, but is not limited to, mobile terminals such as mobile phones, notebook computers, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), vehicle terminals (such as vehicle navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Figure 8 The electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present invention.

[0101] The electronic device includes: a memory and a processor, wherein the processor here may be referred to as a processing device 801 hereinafter, and the memory may include at least one of a read-only memory (ROM) 802, a random access memory (RAM) 803, and a storage device 808 hereinafter, as shown below:

[0102] like Figure 8 As shown, the electronic device 800 may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 801, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 802 or a program loaded from a storage device 808 into a random access memory (RAM) 803. In the RAM 803, various programs and data required for the operation of the electronic device 800 are also stored. The processing device 801, the ROM 802, and the RAM 803 are connected to each other via a bus 804. An input / output (I / O) interface 805 is also connected to the bus 804.

[0103] Typically, the following devices may be connected to the I / O interface 805: input devices 806 including, for example, a touch screen, a touch pad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, etc.; output devices 807 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; storage devices 808 including, for example, a magnetic tape, a hard disk, etc.; and communication devices 809. The communication device 809 may allow the electronic device 800 to communicate with other devices wirelessly or by wire to exchange data. Although Figure 8 The electronic device 800 is shown with various devices, but it should be understood that it is not required to implement or possess all the devices shown. More or fewer devices may be implemented or possessed instead.

[0104] In particular, according to an embodiment of the present invention, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present invention includes a computer program product, which includes a computer program carried on a non-transitory computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication device 809, or installed from the storage device 808, or installed from the ROM 802. When the computer program is executed by the processing device 801, the above-mentioned functions defined in the method of the embodiment of the present invention are executed.

[0105] Based on the above-mentioned method for determining flame morphology based on numerical simulation, an embodiment of the present invention also provides a computer-readable storage medium accordingly, which stores one or more programs, and the one or more programs can be executed by one or more processors to implement the steps in the method for determining flame morphology based on numerical simulation in the above-mentioned embodiments.

[0106] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0107] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for determining flame morphology based on numerical simulation, characterized in that: include: Determine a calculation area in the fire numerical simulation process, wherein the calculation area includes a plurality of first grids, the flame shape includes a flame surface area, a flame height, a volume and a force, wherein the first grid is a grid corresponding to the calculation area of ​​the fire numerical simulation process; determining a flame face region in the calculation region based on the temperature and the fuel concentration of each first grid; Determine a grid set of the flame surface area, and determine the flame height based on the ordinate of a second grid in the grid set; determining a flame volume in the calculation region based on a chemical reaction rate of each first grid; Calculating flame forces based on the flame surface area and the flame volume; The step of determining the flame surface area in the calculation area based on the temperature and fuel concentration of each first grid comprises: Determine the fuel concentration of each first grid, calculate the fuel concentration gradient value of each first grid based on the fuel concentration of each first grid, and if the fuel concentration gradient value of any first grid is infinite, confirm the first grid as a third grid, wherein the third grid is a grid in the first grid whose fuel concentration gradient value is infinite; Determine the temperature of each third grid, if the temperature of any third grid is greater than the fuel ignition point, confirm the third grid as the second grid, and determine the area of ​​the second grid in the calculation area as the flame surface area, wherein the second grid is a grid in the third grid whose temperature is greater than the fuel ignition point; The determining of the flame height based on the ordinate of the second grid in the grid set comprises: Determine the maximum value of the ordinate in the second grid, and determine the maximum value as the maximum flame height; The determining of the flame volume in the calculation region based on the chemical reaction rate of each first grid comprises: The fourth grid in the calculation area is determined based on the chemical reaction rate of each first grid, and the volume of the fourth grid is summed to obtain the flame volume. The calculation formula of the flame volume is: ,in, is the volume of the jth grid in set T, n is the number of elements in set T, and set T is the set of grids that make up the flame volume; Wherein, the fourth grid is a grid in the first grid whose chemical reaction rate is not zero; The chemical reaction rate of the first grid is determined based on the vortex combustion model. The expression of the chemical reaction rate is: in, is the fluid density in the first grid, is the turbulent kinetic energy, is the turbulent kinetic energy dissipation rate, is the mass fraction of any reactant in the grid, is the mass fraction of any generated object in the grid, For the generated is the stoichiometric number of reactants in the chemical reaction equation, is the stoichiometric number of the product in the chemical reaction equation, is the total number of reactants, is the molar mass of the product, is the molar mass of the reactant, A and B are constants; The flame force includes the flame force and the flame force components in different directions, wherein the flame force components in different directions include: in, , and are the components of the flame on the x-axis, y-axis and z-axis respectively, , and , are the accelerations of the flame on the x-axis, y-axis and z-axis respectively, is the number of grids in the second grid, The flame surface The fluid density of the grid, The flame surface The grid volume of the grid, , and They are the first The acceleration of the fluid within a grid.

2. The method for determining flame morphology based on numerical simulation according to claim 1, characterized in that: The flame shape also includes a flame pulsation frequency, and determining the flame pulsation frequency includes: Determining a fifth grid located in the intermittent flame area in the grid set of the flame surface area, wherein the flame surface area includes a continuous flame area, an intermittent flame area, and a buoyancy plume area; Obtaining a curve of a chemical reaction rate changing over time in the fifth grid, and obtaining a flame pulsation period based on the curve; The flame pulsation period is calculated inversely to obtain the flame pulsation frequency.

3. A device for determining flame morphology based on numerical simulation, characterized in that: The method for determining flame morphology based on numerical simulation according to claim 1 or 2 is used to determine the flame morphology, comprising: A calculation region determination module, used to determine a calculation region in a fire numerical simulation process, wherein the calculation region includes a plurality of first grids, and the flame shape includes a flame surface area, a flame height, a volume, and a force; a flame surface region determination module, for determining the flame surface region in the calculation region based on the temperature and fuel concentration of each first grid; A flame height determination module, used to determine a grid set of a flame surface area, and determine the flame height based on the ordinate of a second grid in the grid set; a flame volume determination module, configured to determine the flame volume in the calculation area based on the chemical reaction rate of each first grid; The flame force calculation module is used to calculate the flame force based on the flame surface area and the flame volume.

4. An electronic device, characterized in that: It comprises a memory and a processor, wherein the memory is used to store programs; the processor is coupled to the memory and is used to execute the programs stored in the memory to implement the steps in the method for determining flame morphology based on numerical simulation as described in claim 1 or 2.

5. A computer-readable storage medium, characterized in that: Used to store computer-readable programs or instructions, which, when executed by a processor, can implement the steps in the method for determining flame morphology based on numerical simulation as described in claim 1 or 2.

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