JP2002312342A - Fluid motion analyzing device and method, and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid motion analyzing device capable of stably and easily analyzing the fluid motion even when an hardly analyzable item instable in analysis is included in a non-steady advection diffusion equation under a specific condition. SOLUTION: This fluid motion analyzing device 1 is provided with an integral data calculating part 151 for integrating and calculating an advection term included in the non-steady advection diffusion equation. Further, a non-advection term data calculating part 16 is provided to calculate the non-advection terms as the terms excluding the advection term, included in the non-steady advection diffusion equation by a finite difference method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid motion analysis device for analyzing fluid motion based on an unsteady advection diffusion equation describing a time change of the density of a fluid component, and more particularly to an unsteady advection diffusion equation under a specific condition. The present invention relates to a fluid motion analysis device capable of performing analysis stably and easily when there is a term indicating analysis instability that makes analysis difficult.

[0002]

2. Description of the Related Art Conventionally, there is a display device using a plasma display panel in which a large number of discharge tubes called display cells are arranged in a matrix and the brightness of each display cell is controlled to display an image.

FIG. 1 shows a PDP (Plasma Display Pane).
l) shows the appearance of the display cell 101, and FIG.
1 shows a cross-sectional view. As shown in FIG.
Numeral 1 has a columnar shape and has a display cell 101 inside.
Contains a weakly ionized gas that generates charged particles when a voltage is applied to the gas.

In FIG. 2, a display cell 101 is provided with an anode 102 and a cathode 103, which are electrodes.
The inside contains a weakly ionized gas.

The charged particles are composed of an anode 102, a cathode 1
When a voltage is applied during 03, the electric field moves within the electric field generated by the voltage application. The movement of the charged particles is represented by Z in FIG.
If the fluid can be treated as a fluid having a velocity component v _z in the direction and a velocity component v _r in the r direction indicating the radial direction of the cylinder, the amount of time change of the density n of the charged particles at the sample point V ₀ in the display cell 101 ( The time derivative) is described by an unsteady advection-diffusion equation of Expression (1), for example, as described in IEEJ Technical Report No. 688 (1998) P27, P28. That is, the time variation (time derivative) of the density n of the charged particles at the sample point V ₀ is:
It is represented by the three terms on the right side of Equation 1.

[0006]

(Equation 1) Here, the velocity vector v is represented by v _{z in the z} direction and v
A velocity vector having _r as a component is shown. In addition, D is the diffusion constant of charged particles that are fluid components.

The first term on the right side of the equation (1) is the anode 10
2, an advection term in which charged particles move by a voltage applied between the cathodes 103. The first term, n · (velocity vector v), indicates a flux (flux), and indicates that the advection term is represented by a spatial derivative of the flux.

The second term on the right side of the equation (1) indicates a diffusion term indicating the diffusion of charged particles. In the display cell 101, the density of charged particles is not uniform and varies depending on the location. As described above, when the density of the charged particles varies depending on the location, the charged particles move so as to have a uniform density in the entire display cell 101. That is, the charged particles move from the region where the density of the charged particles is high to the region where the density of the charged particles is low. What shows this phenomenon is the diffusion term.

[0009] The third term on the right side of the equation (1) is a term indicating generation and disappearance of charged particles.

Next, equation (1) is a differential equation and is continuous with respect to time. However, when analyzing equation (1) with a computer, it is necessary to discretize with respect to time. For example, a variable t representing time is discretized as in the method of solving an ordinary differential equation described in “Numerical Calculation Method” edited by Ryo Natori (1998) p117 and p118 issued by Ohmsha.
₁ , t ₂ , t ₃ ... T _i−1 , t _i , and the time interval between t _i−1 and t _i is Δt.

Then, the density n (t _i ) of the charged particles as the fluid component at the time t _i can be approximated by the equation (2) obtained by integrating the equation (1) between t _i−1 and t _i. it can. The density n _i of charged particles, but is also a function of the location as well as a function of time t, not shown explicitly place variables in equation (2).

[0012]

(Equation 2) In the approximation of equation (2), the time _{t i-1} and time _{t i}
Between (n / ∂t) was assumed to be constant at the value at ti _-1 .

Note that (∂n / ∂t) at t _i-1
Is calculated by discretizing equation (1). Specifically, FIG.
If computed at the sample point V ₀ and (∂n / ∂t) As shown in, computed using the density of charged particles at the sample point V ₁ ~V ₈ adjacent (fluid component).

Here, when analyzing the time evolution of the density n of charged particles over a long period of time, the number of evaluations of the equation (1) increases. For this reason, a simple and fast finite difference method is used for discretizing Expression (1). However, especially when the velocity of the fluid component (charged particle) is large, the solution oscillates in time and space due to the error due to the computational accuracy of the computer and the error due to replacing the derivative with the difference. Indicates a state where it is difficult to continue (analysis instability). In particular, the advection term included in the unsteady advection-diffusion equation shown in Expression (1) indicates analytical instability.

Conventionally, as a method of avoiding the above-described analysis instability, it has been proposed to discretize an advection term by a first-order precision upwind difference method of the following equation (3).

[0016]

(Equation 3) Here, n _j , v _zj , and v _rj are the density of the fluid component (charged particles), the z component of the velocity, and the r component of the velocity at the sample point V _j (j is an integer) in FIG. Represents. Further, δ _p and δ _m represent the lengths of the line segments V ₈ V ₀ and V ₀ V ₄ in FIG. 3, respectively.

The above-mentioned upwind difference method is improved so as to reduce the truncation error.
There is a third order upwind difference method shown in FIG.

[0018]

(Equation 4) Here, n _j , v _zj , and v _rj represent the density of the fluid component (charged particle), the z component of the velocity, and the r component of the velocity at the sample point V _j (j is an integer) in FIG. ing. Δ is obtained by making δ _p and δ _m equal.

Further, as a method for coping with the analysis instability, there is a finite volume method using an expression (5) obtained by integrating the expression (1) in a predetermined region, in addition to the above-mentioned upwind difference method.
In the finite volume method, the density of the fluid component (charged particles) is treated as an average value near the sample point, so that the stability is improved.

[0020]

(Equation 5)V_ΩRepresents the volume of the region Ω shown in FIG._ΩIs the area
Represents the area of the boundary of Ω. Note that V_ΩIs the central axis
Volume (2πR) _gd
S_ΩR_gIs equal to the center of gravity of the region Ω).

Here, as an example of a generation term (a term including G) in the finite volume method shown in Expression (5), for example, FIG.
The volume obtained by one rotation around the area indicated Omega _lu (center axis (z-axis) to _{(2πR g} dS Ωlu; _{R g} is, regions Omega _lu
Center of gravity). The generation term in ()) is represented by Expression (6). Therefore, the volume integral is as shown in Expression (7).

[0022]

(Equation 6)

[0023]

(Equation 7) r ₀ represents the coordinate of the sample point V _{0 in} the r direction, and z
₀ represents coordinates in the z direction. Also, λ _m is shown in FIG.
Represents the length of the line segment V ₀ V ₂ at. Note that G _j
Indicates a generation term at a sample point V _j (j is an integer).

[0024]

However, when the spatial variation of the velocity of the fluid component (charged particles) is large, in other words, when the spatial derivative of the velocity of the charged particles changes drastically, the above-mentioned upwind difference method is not sufficient. There has been a problem that stability cannot be ensured and analysis of fluid motion becomes difficult.

On the other hand, when the finite volume method is used, as described above, the volume integral of the generated term is as shown in equation (7), and the number of sampling points required for the operation is larger than that of the finite difference method. There was a point. In other words, when there are many types of fluid components, there is a problem that the amount of calculation becomes extremely large because the number of sample points is set large in order to grasp the characteristics of each fluid component.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to solve the problem of analysis instability that makes analysis difficult in the unsteady advection-diffusion equation under specific conditions. An object of the present invention is to provide a fluid motion analysis device that can stably analyze fluid motion analysis and reduce the amount of calculation even when there is a term indicated.

[0027]

In order to achieve the above object,
The fluid motion analysis device according to the present invention is a fluid motion analysis device that analyzes fluid motion based on an unsteady advection diffusion equation that describes a time change of the density of a fluid component. And an integral data calculator for calculating integral data based on an integral of the analytical instability term indicating analytical instability that makes analysis difficult, and storing the integral data calculated by the integral data calculator. And a discretized data calculation unit that calculates discretized data obtained by discretizing a time change of the density of the fluid component based on the integrated data stored in the integrated data storage unit. It is characterized by.

With such a configuration, when there is a term showing analysis instability that makes analysis difficult in the unsteady advection-diffusion equation under specific conditions, the analysis can be performed stably. In addition, since not all the terms included in the unsteady advection-diffusion equation are integrated, the amount of calculation for performing the analysis can be reduced.

Further, the analysis instability term is characterized in that it is an advection term included in the unsteady advection-diffusion equation.

By integrating the advection term that indicates analytical instability when the spatial variation of the velocity of the fluid component is large, it is possible to stably analyze the fluid motion.

Further, the fluid motion analyzing apparatus further calculates a non-convection term data using a finite difference method for a non-convection term other than the advection term included in the unsteady advection-diffusion equation. A non-convection term data storage unit that stores the non-convection term data calculated by the non-convection term data calculation unit, wherein the discretized data calculation unit includes the integration data and the non-convection term data storage The discretized data is calculated based on the non-advection term data stored in the section.

As described above, since the calculation of the non-convection term other than the advection term is performed by using the finite difference method, the calculation amount of the non-convection term is reduced, and the fluid motion can be easily analyzed.

Further, the fluid motion analysis method according to the present invention provides
In a fluid motion analysis method for analyzing fluid motion based on an unsteady advection diffusion equation describing a temporal change in the density of a fluid component, some of the terms included in the unsteady advection diffusion equation are difficult to analyze. An integration data calculation step of calculating integration data based on an integration of an analysis instability term indicating an analysis instability; an integration data storage step of storing integration data calculated in the integration data calculation step; A discretized data calculation step of calculating discretized data obtained by discretizing a time change of the density of the fluid component based on the integrated data stored in the storage step.

With such a configuration, when there is a term showing analysis instability that makes analysis difficult in the unsteady advection-diffusion equation under specific conditions, the analysis can be performed stably. In addition, since not all the terms included in the unsteady advection-diffusion equation are integrated, the amount of calculation when performing analysis can be reduced.

Further, the analysis instability term is characterized in that it is an advection term included in the unsteady advection-diffusion equation.

By integrating the advection term that indicates analytical instability when the spatial variation of the velocity of the fluid component is large, the fluid motion can be analyzed stably.

Further, the fluid motion analysis method further comprises calculating a non-convection term data using a finite difference method for a non-convection term other than the advection term included in the unsteady advection-diffusion equation. A non-convection term data storage step for storing the non-convection term data calculated in the non-convection term data calculation step, wherein the discretized data calculation step includes the integration data and the non-convection term data storage The discretized data is calculated based on the non-advection term data stored in the step.

As described above, since the calculation of the non-convection term other than the advection term is performed by using the finite difference method, the calculation amount of the non-convection term is reduced, and the fluid motion can be easily analyzed.

Further, the computer-readable recording medium according to the present invention includes a computer which is a fluid motion analysis device for analyzing fluid motion based on an unsteady advection-diffusion equation describing a temporal change in the density of a fluid component. An integral data calculation process for calculating integral data based on a part of the term included in the unsteady advection-diffusion equation and integrating an analytical instability term indicating analytical instability that makes analysis difficult; An integral data storage process for storing the integral data calculated in the data calculation process; and a discrete data for discretizing the time change of the density of the fluid component based on the integral data stored in the integral data storage process. Characterized in that a program for executing the coded data calculation process is recorded.

With such a configuration, the analysis can be performed stably when there is a term showing analysis instability that makes analysis difficult in the unsteady advection-diffusion equation under specific conditions. In addition, since not all the terms included in the unsteady advection-diffusion equation are integrated, the amount of calculation for performing the analysis can be reduced.

Further, the analysis instability term is characterized in that it is an advection term included in the unsteady advection-diffusion equation.

By integrating an advection term showing analytical instability when the spatial variation of the velocity of the fluid component is large, the fluid motion can be analyzed stably.

Further, the computer-readable recording medium may further include a computer that serves as the fluid motion analysis device, using a finite difference method for a non-convection term other than the advection term included in the unsteady advection-diffusion equation. A program for executing a non-convection term data calculation process of calculating non-convection term data and a non-convection term data storage process of storing the non-convection term data calculated in the non-convection term data calculation process. The discretized data calculation process is characterized in that the discretized data is calculated based on the integral data and the non-convection term data stored in the non-convection term data storage process.

As described above, since the calculation of the non-convection term other than the advection term is performed by using the finite difference method, the calculation amount of the non-convection term is reduced, and the fluid motion can be easily analyzed.

[0045]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the fluid motion analyzer according to the present invention will be described with reference to the drawings. First, the principle of an analysis method used in the fluid motion analysis device according to the embodiment will be briefly described.

When the spatial variation of the velocity of the fluid component (charged particles) is large or the velocity is large, it is necessary to consider that the advection term included in the unsteady advection-diffusion equation shown in the equation (1) indicates analytical instability. In order to stably analyze the advection term, the calculation is performed in an integral form as in the finite volume method. For the diffusion term, generation term, annihilation term and the like other than the advection term included in the unsteady advection-diffusion equation, the finite difference method is used to reduce the amount of calculation.

That is, when analyzing the time evolution of the fluid component based on the unsteady advection-diffusion equation, the fluid motion analysis apparatus according to the embodiment includes a portion corresponding to the advection term and an equation (8) as shown in equation (8). As shown in 9), the calculation is performed by dividing into terms other than the advection term (referred to as non-convection terms).

Specifically, the convection term is calculated using the finite volume method, and the non-convection term is calculated using the finite difference method.

[0049]

(Equation 8)

[0050]

(Equation 9) However, n * in Expressions (8) and (9) is an auxiliary variable in operation and has no physical meaning. That is, when Equations (8) and (9) are added, n * on the left side becomes
Time change of the canceled and discretized density (n (t _i )
−n (t _i−1 )) / Δt.

Here, the finite difference method is operated using values at sample points, whereas the finite volume method uses an average value in a predetermined area including the sample points. Therefore, strictly speaking, the meaning of the density n of the target fluid component generally does not match, but (a) the volume of the predetermined region is almost zero.
(B) If the density n satisfies one of the predetermined conditions in a predetermined area, the equation (10) is satisfied.

[0052]

(Equation 10) That is, ∇ · (nv) can be included in the integral. Therefore, if the size of the region Ω is set so that the density n of the fluid component can be regarded as substantially constant, the equation (8) uses Gauss's theorem which is a conversion equation of the volume integral and the area integral shown in the equation (11). Equation (12) results.

[0053]

[Equation 11] Here, f is a vector quantity.

[0054]

(Equation 12) In this way, the advection term indicating the analysis instability can be integrated in the predetermined region, and the stable fluid motion can be analyzed.

Next, the configuration of the fluid motion analyzer according to the embodiment will be described. A description will be given of a case where the fluid motion analysis apparatus according to the embodiment analyzes the motion of a fluid containing charged particles in the axially symmetric display cell 101 used in the PDP shown in FIGS. 1 and 2 as a fluid component. .

FIG. 4 is a diagram showing a functional configuration of the fluid motion analyzer. In FIG. 4, the fluid motion analysis device 1 includes:
Initial setting unit 11, sample point data generation unit 12, electric field data calculation unit 13, parameter calculation unit 14, advection term data calculation unit 15, non-convection term data calculation unit 16, discretization data calculation unit 17, density data calculation unit 18 , Consistency judgment unit 1
9, a data storage unit 20.

The initial setting section 11 is configured to be able to set initial conditions for analyzing fluid motion. For example, the initial setting unit 11 is configured to be able to input and set conditions such as the cylindrical radius and length of the display cell 101, the size and coordinates of the electrodes of the anode 102 and the cathode 103, the internal gas composition, and the like. .

Next, the sample point data generator 12 sets coordinates in the internal space of the display cell 101 as shown in FIGS. 2 and 3, and sets sample points corresponding to the positions of the coordinates (sample points). It is configured to generate data. For example, the sample point data at the sample point V ₀ is Z
It is composed of z ₀ indicating the coordinates in the axial direction, r ₀ indicating the coordinates in the r direction, and the like.

Hereinafter, the density of the fluid component (charged particles and the like) in the calculation region is treated as the density at the sample point described above, and the time change of the density is calculated by the unsteady advection-diffusion equation of Expression (1). Is parsed.

The electric field data calculator 13 is configured to calculate electric field data indicating an electric field at each sample point. When dealing with charged particles in a weakly ionized gas, the velocity appearing in the unsteady advection-diffusion equation shown in the equation (1) does not depend on the pressure in the display cell 101, and is almost exclusively due to the electric field in the display cell 101. It is determined. Therefore, in order to calculate the velocity data indicating the velocity appearing in the unsteady advection-diffusion equation, it is necessary to first calculate the electric field data indicating the electric field. Therefore, the electric field data calculation unit 1
3 are provided. In calculating the electric field data, the electric potential at the electrodes of the anode 102 and the cathode 103 is given as a boundary condition, and electric potential data indicating the electric potential at each sample point and electric field data indicating the electric field are obtained.

Next, the parameter calculator 14 is configured to be able to calculate velocity data indicating the velocity of the fluid component, using the electric field data at each sample point calculated by the electric field data calculator 13 described above. I have. That is,
In the unsteady advection-diffusion equation shown in Expression (1), the apparatus is configured to calculate data corresponding to variables (parameters) other than the density of the fluid component.

The advection term data calculator 15 is configured to calculate advection term data corresponding to the advection term included in the unsteady advection-diffusion equation.
1.

The integral data calculation section 151 executes the area integration on the right side of the equation (12), which is obtained by integrating the advection term indicating the analysis anxiety, and indicates the value obtained by dividing the integrated value by the volume of the region. It is configured to calculate integral data and calculate a temporal change of the density of the fluid component due to the advection term. For example, the calculation of the area integral at the sample point V ₀ shown in FIG. 3 are performed over a S _Omega boundary area of the region Omega. Incidentally, integrated data calculating unit 151, for each sample point, performing the area integral as we did in the sample point V _0.

By calculating in this way, it is possible to stably calculate the advection term showing the analysis anxiety.

The non-advection term data calculation section 16 calculates the equation (9)
Is configured to calculate non-convection term data corresponding to non-convection terms other than the advection term using the finite difference method for the equation shown in, and calculate the time change of the density of the fluid component due to the non-convection term . The non-convection term data calculation unit 16 calculates non-convection term data at all sample points.

By performing the calculation as described above, the calculation can be performed easily and at a high speed.

Next, the discretized data calculation unit 17 adds the integral data calculated by the advection term data calculation unit 15 and the non-convection term data calculated by the non-convection term data calculation unit 16 to obtain the discretized fluid. It is configured to calculate discretized data indicating a temporal change in the density of the component. The discretized data calculation unit 17 calculates non-convection term data at all sample points.

The density data calculator 18 uses the discretized data calculated by the discretized data calculator 17 and calculates
Is configured to calculate density data indicating the density of the fluid component at time t _i (i is an integer) based on the equation shown in (1). The density data calculator 18 calculates density data at all sample points.

The consistency judging section 19 judges whether or not the electric field data calculated based on the density data calculated by the above-described density data calculating section 18 is compatible with the electric field data calculated by the above-described electric field data calculating section 13. It is configured as follows.

That is, the density distribution of the fluid component indicated by the density data calculated by the density data calculation unit 18 is as follows:
Since the distribution of the charge density affects the calculation of the electric field data calculation unit 13, in order to obtain consistency so that the calculation results of the calculation units such as the density data calculation unit 18 and the electric field data calculation unit 13 do not contradict each other, A consistency determination unit 19 is provided.

Next, the data storage unit 20 is configured to store the data calculated by each of the calculation units described above.
For example, it is configured to include an integration data storage unit 201 that stores the integration data calculated by the integration data calculation unit 15 and a non-advection term data storage unit 202 that stores the non-advection term data. The data storage unit 20 includes, for example, a RAM.

The fluid motion analyzer according to the embodiment is
It is configured as described above, and the operation and action will be described below.

[0073] In the following, the operation of analyzing the density of the fluid component at time t ₁ than the density of the fluid component at time t _0, will be described with reference to FIGS. 4 and 5.

First, when initial setting is performed in the initial setting unit 11 (S101), coordinates corresponding to the internal space of the display cell 101 are set, and sample point data indicating the position of each point of the coordinates is generated. Then, the generated sample point data is stored in the data storage unit 20 (S102).

Next, the electric field data calculator 13 calculates electric field data indicating the electric field at each sample point.
The calculated electric field data is stored in the data storage unit 20 (S103). Then, the parameter calculation unit 14 uses the electric field data at each sample point stored in the data storage unit 20 to calculate parameters such as the velocity of the fluid component other than the density of the fluid component in the unsteady advection-diffusion equation for each sample point. calculate. Then, the calculated parameters are stored in the data storage unit 20 (S104).

Next, the integral data calculation section 151 executes the area integration represented by the equation (12), and calculates, for each sample point, integral data indicating a value obtained by dividing the integral value by the volume of the region (integral data). Calculation step) (S105). And
The calculated integration data is stored in the integration data storage unit 201 (integration data storage step) (S106).

Next, in the non-convection term data calculation unit 16, non-convection term data is calculated for each sample point using the finite difference method for the equation shown in Expression (9) (non-convection term data calculation step). ) (S107), the calculated non-convection term data is stored in the non-convection term data storage unit 202 (non-convection term data storage step) (S108).

Then, the discretized data calculation section 17 adds the integral data stored in the integral data storage section 201 and the non-convection term data stored in the non-convection term data storage section 202 to discretize. Discrete data indicating the time change of the density of the fluid component is calculated for each sample point. And
The calculated discretized data is stored in the data storage unit 20 (S109).

Next, using the discretized data stored in the data storage unit 20 and the density data at time t ₀ , the density data calculation unit 18 calculates the density indicating the density at time t ₁ from equation (2). Data is calculated for each sample point. Then, the calculated density data is stored in the data storage unit 20.
(S110).

Then, the consistency judging unit 19 judges whether the calculation results obtained by the calculation units such as the density data calculation unit 18 and the electric field data calculation unit 13 are inconsistent with each other (S111).

If there is a contradiction, the process returns to S103 and the following steps are repeated until the calculation results by the respective calculation units no longer contradict.

[0082] On the other hand, if not contradictory, the density data are determined at time _{t 1.}

[0083] When calculating the density data at further time t ₂ later, on the basis of the density data at time t _1, repeating the steps S103 and subsequent operation described above.

As described above, the fluid motion analysis apparatus according to the present embodiment can be used under the specific conditions, even when there is a term showing analysis instability that makes analysis difficult in the unsteady advection-diffusion equation. Motion analysis can be performed stably, and the amount of calculation required for analysis can be reduced. Therefore, it is possible to stably and easily check the electrical characteristics and the like of the display cell to be calculated.

When weakly ionized gas is used as in this embodiment, a large strain electric field is generated depending on the calculation conditions, and the spatial fluctuation of the velocity of the fluid component becomes large. For this reason, if an unstable calculation method is used to analyze the unsteady advection-diffusion equation shown in Expression (1), the analysis becomes difficult. However, according to the fluid motion analysis device of the embodiment, the advection term is integrated. Therefore, the fluid motion can be stably analyzed without including the first derivative of the velocity, which is the main cause of the instability.

According to the fluid motion analysis apparatus of the embodiment, the non-convection term other than the advection term is calculated using only the data at the sample points using the finite difference method. The amount is reduced to about 10% compared to the finite volume method,
Fluid motion analysis can be easily performed.

[0087]

According to the present invention, it is possible to stably analyze the fluid motion even when there is a term showing analysis instability that makes analysis difficult in the unsteady advection-diffusion equation under specific conditions. And the effect of reducing the amount of calculation for analysis is obtained.

[0088]

[Brief description of the drawings]

FIG. 1 is a diagram showing the appearance of a display cell.

FIG. 2 is a cross-sectional view of a display cell.

FIG. 3 is a diagram schematically showing a calculation area.

FIG. 4 is a diagram showing a functional configuration of a fluid motion analysis device according to an embodiment.

FIG. 5 is a flowchart showing an operation of the fluid motion analysis device in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluid motion analysis apparatus 11 Initial setting part 12 Sample point data generation part 13 Electric field data calculation part 14 Parameter calculation part 15 Advection term data calculation part 16 Non-convection term data calculation part 17 Discretization data calculation part 18 Density data calculation part 19 Matching Sex determination unit 20 Data storage unit 151 Integration data calculation unit 201 Integration data storage unit 202 Non-advection term data storage unit

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 5B056 BB04

Claims (9)

[Claims] 1. A fluid motion analysis device for analyzing fluid motion based on an unsteady advection-diffusion equation describing a temporal change in the density of a fluid component, wherein a part of the terms included in the unsteady advection-diffusion equation An integration data calculation unit that calculates integration data based on an integration of an analysis instability term indicating analysis instability that makes analysis difficult; and an integration data storage unit that stores integration data calculated by the integration data calculation unit. And a discretization data calculation unit that calculates discretization data obtained by discretizing the time change of the density of the fluid component based on the integration data stored in the integration data storage unit. Motion analysis device. 2. The fluid motion analysis device according to claim 1, wherein the analysis instability term is an advection term included in the unsteady advection-diffusion equation. 3. The non-convection term for calculating non-convection term data using a finite difference method for a non-convection term other than the advection term included in the unsteady advection-diffusion equation. A non-convection term data storage unit that stores the non-convection term data calculated by the non-convection term data calculation unit, wherein the discretized data calculation unit stores the integral data and the non-convection term data storage The fluid motion analysis device according to claim 2, wherein the discretized data is calculated based on the non-convection term data stored in the section. 4. A fluid motion analysis method for analyzing fluid motion based on an unsteady advection-diffusion equation that describes a temporal change in the density of a fluid component, wherein a part of terms included in the unsteady advection-diffusion equation An integration data calculation step of calculating integration data based on an integrated analysis instability term indicating analysis instability that makes analysis difficult; and an integration data storage step of storing integration data calculated in the integration data calculation step. And a discretization data calculation step of calculating discretization data obtained by discretizing the time change of the density of the fluid component based on the integration data stored in the integration data storage step. Method. 5. The method according to claim 4, wherein the analysis instability term is an advection term included in the unsteady advection-diffusion equation. 6. The fluid motion analysis method further includes calculating a non-convection term data using a finite difference method for a non-convection term other than the advection term included in the unsteady advection-diffusion equation. A non-convection term data storage step for storing the non-convection term data calculated in the non-convection term data calculation step, wherein the discretized data calculation step includes the integration data and the non-convection term data storage 6. The fluid motion analysis method according to claim 5, wherein the discretized data is calculated based on the non-advection term data stored in the step. 7. A computer serving as a fluid motion analysis device for analyzing fluid motion based on an unsteady advection diffusion equation describing a time change of the density of a fluid component, wherein a computer includes a partial term included in the unsteady advection diffusion equation An integration data calculation process for calculating integration data based on an integration of an analysis instability term indicating analysis instability that makes analysis difficult; and an integration storing the integration data calculated in the integration data calculation process. A program for executing a data storage process and a discretized data calculation process of calculating discretized data obtained by discretizing the time change of the density of the fluid component based on the integral data stored by the integral data storage process is provided. A computer-readable recording medium that has been recorded. 8. The computer-readable recording medium according to claim 7, wherein the analysis instability term is an advection term included in the unsteady advection-diffusion equation. 9. The computer-readable recording medium further uses a finite difference method for a non-convection term other than an advection term included in the unsteady advection-diffusion equation in a computer serving as the fluid motion analysis apparatus. A non-convection term data calculation process for calculating the non-convection term data, and a non-convection term data storage process for storing the non-convection term data calculated in the non-convection term data calculation process. The computer according to claim 8, wherein the discretized data calculation process calculates the discretized data based on the integral data and the non-convection term data stored in the non-convection term data storage process. A readable recording medium.