CN111241682A - Pipeline section flow prediction analysis method and device - Google Patents
Pipeline section flow prediction analysis method and device Download PDFInfo
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- CN111241682A CN111241682A CN202010034734.7A CN202010034734A CN111241682A CN 111241682 A CN111241682 A CN 111241682A CN 202010034734 A CN202010034734 A CN 202010034734A CN 111241682 A CN111241682 A CN 111241682A
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Abstract
The application provides a method and a device for predicting and analyzing flow of a pipeline section. The method comprises the following steps: according to the input pipeline diameter, pipeline inlet flow, fluid density, fluid viscosity, preset pressure gradient and a preset velocity field, a momentum equation and a turbulence model are combined, so that an effective value of turbulence kinetic energy, an effective value of specific dissipation rate of turbulence kinetic energy and an effective value of turbulence viscosity of the pipeline cross-section flow are determined, the pipeline cross-section pressure gradient and the pipeline cross-section flow field distribution under different flow rates are obtained, visualization of the pipeline cross-section flow is achieved, guidance is provided for pipeline operation, meanwhile, the influence of the drag reducer can be continuously considered on the basis of the prediction according to the requirements of users, the strain parameter of the drag reducer is coupled, the influence of the drag reducer on the pipeline cross-section flow is analyzed, and the analysis efficiency is improved.
Description
Technical Field
The embodiment of the application relates to the field of petroleum transportation, in particular to a method and a device for predicting and analyzing flow of a pipeline section.
Background
The rapid development of the petroleum industry leads the pipeline transportation amount to increase day by day, and different from a crude oil pipeline, a finished oil pipeline is a development type pipeline, and as the market is continuously expanded, a development opportunity is created for the finished oil pipeline. Pipeline transportation plays an important role in the petroleum and natural gas industry and even the world economy, increases the transportation capacity of oil and gas long-distance pipelines, reduces the flow resistance in the oil and gas transportation process, reduces the energy consumption and the operation cost of pipeline transportation, improves the operation elasticity, the safety and the economy of the pipelines, and is an important subject which is continuously researched and solved by pipeline science and technology workers for many years. In the prior art, drag reducers are added to short-distance channel fluid, and a conventional full three-dimensional numerical simulation method and a turbulence model are adopted to simulate and predict the pressure gradient and flow field distribution of the fluid. However, the method has low efficiency, and it is difficult to quickly predict the flow field and the pressure gradient in the pipeline after the flow of the on-site finished oil pipeline is adjusted.
Disclosure of Invention
The embodiment of the application provides a method and a device for predicting and analyzing the flow of a pipeline section, which aim to solve the problem of low analysis efficiency of a flow field and a pressure gradient in a finished oil pipeline on site.
In a first aspect, an embodiment of the present application provides a method for predictive analysis of a cross-sectional flow of a pipeline, including:
acquiring input parameters of a pipeline and object parameters of fluid in the pipeline, wherein the parameters of the pipeline comprise the diameter of the pipeline and the flow rate of an inlet of the pipeline, and the object parameters of the fluid comprise the density of the fluid and the viscosity of the fluid;
acquiring a preset pressure gradient and a preset speed field;
determining an effective value of turbulent kinetic energy, an effective value of specific dissipation ratio of turbulent kinetic energy and an effective value of turbulent viscosity according to a turbulent model equation, parameters of the pipeline and object parameters of fluid in the pipeline, the preset pressure gradient and the preset velocity field;
obtaining a calculated velocity field according to a strain parameter and a momentum equation of a drag reducer added into the fluid;
and outputting the preset pressure gradient, the calculated speed field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity.
Optionally, the determining an effective value of turbulent kinetic energy, an effective value of specific dissipation ratio of turbulent kinetic energy, and an effective value of turbulent viscosity according to a turbulent model equation, parameters of the pipe, and object parameters of fluid in the pipe, the preset pressure gradient, and the preset velocity field includes:
determining an initial value of turbulent flow energy and an initial value of specific dissipation ratio of turbulent flow kinetic energy according to a turbulent flow model equation, parameters of the pipeline and object parameters of fluid in the pipeline, the preset pressure gradient and the preset velocity field;
determining an initial value of the turbulent viscosity according to the initial value of the turbulent kinetic energy, the initial value of the specific dissipation ratio of the turbulent kinetic energy and the density of the fluid;
and determining the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity according to the initial values of the turbulent viscosity, the turbulent kinetic energy and the turbulent model equation.
Optionally, the method further comprises:
determining a strain parameter of a drag reducer added to the fluid according to a constitutive equation.
Optionally, before outputting the preset pressure gradient, the calculated velocity field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation ratio of the turbulent kinetic energy, and the effective value of the turbulent viscosity, the method further includes:
determining the cross-sectional flow of the pipeline according to the calculated velocity field and the mass conservation equation;
outputting the preset pressure gradient, the calculated velocity field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation ratio of the turbulent kinetic energy and the effective value of the turbulent viscosity, comprising:
and if the difference value between the cross-section flow of the pipeline and the flow of the pipeline inlet is smaller than a first preset difference value, outputting the preset pressure gradient, the calculated speed field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity.
Optionally, the method further comprises:
and if the difference value between the cross-sectional flow of the pipeline and the flow of the pipeline inlet is larger than or equal to a first preset difference value, changing the value of the preset pressure gradient according to a dichotomy.
Optionally, before outputting the calculated velocity field, the method further includes:
judging whether the difference value between the calculated speed field and the preset speed field is smaller than a second preset difference value or not;
the output calculated velocity field includes:
and if the difference value between the calculated speed field and the preset speed field is smaller than a second preset difference value, outputting the calculated speed field.
Optionally, the method further comprises:
and if the difference value between the calculated speed field and the preset speed field is greater than or equal to a second preset difference value, changing the value of the preset speed field into the value of the calculated speed field.
In a second aspect, an embodiment of the present application provides a device for predicting and analyzing a cross-sectional flow of a pipeline, including:
the system comprises a first acquisition module, a second acquisition module and a third acquisition module, wherein the first acquisition module is used for acquiring input parameters of a pipeline and object parameters of fluid in the pipeline, the parameters of the pipeline comprise the diameter of the pipeline and the flow rate of an inlet of the pipeline, and the object parameters of the fluid comprise the density of the fluid and the viscosity of the fluid;
the second acquisition module is used for acquiring a preset pressure gradient and a preset speed field;
the first processing module is used for determining an effective value of turbulent kinetic energy, an effective value of specific dissipation ratio of turbulent kinetic energy and an effective value of turbulent viscosity according to a turbulent model equation, parameters of the pipeline, object parameters of fluid in the pipeline, the preset pressure gradient and the preset velocity field;
the second processing module is used for obtaining a calculated velocity field according to a strain parameter and a momentum equation of a drag reducer added into the fluid;
and the output module is used for outputting the preset pressure gradient, the calculated speed field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity.
Optionally, the first processing module is specifically configured to:
determining an initial value of turbulent flow energy and an initial value of specific dissipation ratio of turbulent flow kinetic energy according to a turbulent flow model equation, parameters of the pipeline and object parameters of fluid in the pipeline, the preset pressure gradient and the preset velocity field;
determining an initial value of the turbulent viscosity according to the initial value of the turbulent kinetic energy, the initial value of the specific dissipation ratio of the turbulent kinetic energy and the density of the fluid;
and determining the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity according to the initial values of the turbulent viscosity, the turbulent kinetic energy and the turbulent model equation.
Optionally, the apparatus further comprises:
and the third processing module is used for determining a strain parameter of the drag reducer added into the fluid according to the constitutive equation.
Optionally, before the output module, the method further includes: a fourth processing module;
the fourth processing module is used for determining the cross-sectional flow of the pipeline according to the calculated velocity field and the mass conservation equation;
the output module is specifically configured to:
and if the difference value between the cross-section flow of the pipeline and the flow of the pipeline inlet is smaller than a first preset difference value, outputting the preset pressure gradient, the calculated speed field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity.
The output module is further configured to:
and if the difference value between the cross-sectional flow of the pipeline and the flow of the pipeline inlet is larger than or equal to a first preset difference value, changing the value of the preset pressure gradient according to a dichotomy.
Optionally, before the outputting module outputs the calculated speed field, the method further includes: a judgment module;
the judging module is used for judging whether the difference value between the calculated speed field and the preset speed field is smaller than a second preset difference value or not;
the output module is specifically configured to:
and if the difference value between the calculated speed field and the preset speed field is smaller than a second preset difference value, outputting the calculated speed field.
Optionally, the output module is further configured to:
and if the difference value between the calculated speed field and the preset speed field is greater than or equal to a second preset difference value, changing the value of the preset speed field into the value of the calculated speed field.
In a third aspect, an embodiment of the present application provides an electronic device, including:
a memory for storing program instructions;
a processor for calling and executing the program instructions in the memory to perform the method for predictive analysis of flow in a pipe section according to the first aspect of the present application.
In a fourth aspect, embodiments of the present application provide a computer-readable storage medium, which stores a computer program, and when the computer program is executed by a processor, the computer program implements a pipe cross-section flow prediction analysis method according to the first aspect of the present application.
According to the method and the device for predicting and analyzing the flow of the cross section of the pipeline, the effective value of turbulent kinetic energy, the effective value of specific dissipation rate of turbulent kinetic energy and the effective value of turbulent viscosity are determined according to the diameter of the input pipeline, the flow of the inlet of the pipeline, the density and the viscosity of fluid, a preset pressure gradient and a preset velocity field as well as a turbulent equation; then, obtaining a calculated velocity field according to a strain parameter and a momentum equation of the drag reducer added into the fluid; and then outputting the preset pressure gradient, the calculated speed field, the effective value of turbulent kinetic energy, the effective value of specific dissipation rate of turbulent kinetic energy and the effective value of turbulent viscosity, predicting the flow condition of the fluid in the pipeline, effectively analyzing the drag reduction rate of the pipe flow under different flow rates and the change of the physical property of the drag reduction agent, the change rule of the pressure gradient in the pipeline and the distribution condition of the flow field, and improving the analysis efficiency.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.
Fig. 1 is a schematic view of an application scenario provided in an embodiment of the present application;
FIG. 2 is a schematic flow chart of a method for predictive analysis of flow in a cross-section of a pipeline according to an embodiment of the present application;
FIG. 3 is a schematic view of a pipe geometry in a Cartesian coordinate system according to an embodiment of the present application;
FIG. 4 is a schematic view of a pipe geometry in a bi-polar coordinate system according to an embodiment of the present disclosure;
FIG. 5 is a schematic flow chart of a method for predictive analysis of flow in a cross-section of a pipeline according to another embodiment of the present application;
FIG. 6 is the calculated pipeline fluid section velocity contour plot provided in accordance with an embodiment of the present application;
FIG. 7 is a cross-sectional velocity profile at the centerline of a pipeline as provided by an embodiment of the present application;
FIG. 8 is a significant value contour plot of the turbulent kinetic energy provided by an embodiment of the present application;
FIG. 9 is a plot of the effective value contour of the specific dissipation ratio of the turbulent kinetic energy provided by an embodiment of the present application;
FIG. 10 is a plot of the effective value contour of the turbulent viscosity provided by an embodiment of the present application;
fig. 11 is a schematic structural diagram of a device for predicting and analyzing a flow in a cross section of a pipeline according to an embodiment of the present application;
fig. 12 is a schematic structural diagram of an electronic device according to an embodiment of the present application;
fig. 13 is a schematic structural diagram of an electronic device according to another embodiment of the present application.
Detailed Description
The finished oil long-distance pipeline in China has the characteristics of high Reynolds number, large pipe diameter, drag reducer addition and the like, and the pressure gradient and flow field distribution obtained by different drag reducers and flow rates are different, so that the normal operation of the pipeline is influenced. In order to realize simulation prediction analysis at an industrial level and analyze and master the flow of the fluid in the pipeline and the influence rule of the drag reducer on the fluid in the pipeline, a turbulence drag reduction prediction method based on a bipolar coordinate coupling drag reducer constitutive equation is provided. The frictional pressure drop (or frictional resistance) restricts the flow of fluid in the pipe, resulting in a reduced fluid transport or increased energy consumption in the pipe. The chemical additive can be generally used for reducing the frictional resistance of the fluid in a long-distance pipeline system, improving the conveying capacity, and has important significance for saving energy and investment and accelerating the development and utilization of oil products. Drag Reducing Agent (DRA), which is a relatively effective chemical additive for pipelines, is used to reduce the flow resistance of fluids, and is an important means for improving the flow capacity of pipelines and reducing energy consumption in a specific period and a specific section, and the ability of pipeline transportation can be rapidly and economically expanded. The flow resistance of the fluid can be reduced in a turbulent state after the Reynolds number is more than 2000 by adding a small amount of high molecular polymer into the fluid in the pipeline, and the method is called high polymer drag reduction.
In the following, some terms in the present application are explained to facilitate understanding by those skilled in the art:
a turbulence model: the physical model is used for describing the turbulent viscosity distribution of the fluid in the flow channel when the fluid is in turbulent flow. Turbulent flow is a flow state of fluid, when the flow velocity in a pipeline is increased by more than 2000 Reynolds numbers, flow lines are not clearly distinguished, a plurality of small vortexes exist in a flow field, laminar flow is damaged, and sliding and mixing are carried out between adjacent flow layers, so that the flow resistance of the fluid is increased nonlinearly.
Constitutive equation: the model is used for describing the molecular deformation relationship after the polymer is subjected to force.
Bipolar coordinates: a curvilinear coordinate system for describing the circular tube.
Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.
The embodiment of the present application may be applied to an electronic device, and fig. 1 is a schematic view of an application scenario provided in an embodiment of the present application, as shown in fig. 1, the electronic device may include, for example, a server, a computer, a mobile terminal, and the like, and the mobile terminal includes: cell-phone, panel computer, wearable equipment etc. do not do the restriction to this application.
The technical solution of the present application is described below with reference to several specific embodiments.
Fig. 2 is a schematic flow chart of a method for predictive analysis of a cross-sectional flow of a pipeline according to an embodiment of the present application, where as shown in fig. 2, the method according to an embodiment of the present application may include:
s201, obtaining input parameters of a pipeline and object parameters of fluid in the pipeline, wherein the parameters of the pipeline comprise the diameter of the pipeline and the flow of an inlet of the pipeline, and the object parameters of the fluid comprise the density of the fluid and the viscosity of the fluid.
Before the input parameters of the pipeline and the object parameters of the fluid in the pipeline are obtained, the parameters of the pipeline and the object parameters of the fluid in the pipeline input by the user are received, and the parameters of the pipeline and the object parameters of the fluid in the pipeline input by the user are obtained in a cartesian coordinate system, fig. 3 is a schematic view of a pipeline geometry in the cartesian coordinate system provided by an embodiment of the present application, as shown in fig. 3. The parameters of the pipeline in the cartesian coordinate system may include the diameter of the pipeline, the flow rate of the pipeline inlet, the roughness of the pipeline wall surface, the placement angle of the pipeline, the length of the pipeline, and the like; the object parameters of the fluid may include the density of the fluid in the pipe, the viscosity of the fluid, and the like. Since the fluid within the pipe is incompressible, the flow is the same anywhere within the pipe.
The parameters of the pipeline and the object parameters of the fluid in the pipeline under the Cartesian coordinate system input by the user are converted into the parameters of the pipeline and the object parameters of the fluid in the pipeline under the bipolar coordinate system, and the obtained input parameters of the pipeline and the object parameters of the fluid in the pipeline are the parameters of the pipeline and the object parameters of the fluid in the pipeline under the bipolar coordinate system. Fig. 4 is a schematic view of a pipe geometry in a bi-polar coordinate system according to an embodiment of the present application, as shown in fig. 4. The conversion process of the cartesian coordinate system and the double click coordinate system is as follows:
for example, the coordinates of the Cartesian coordinate system are described as (x, y, z) and the coordinates of the bipolar coordinate system are described as (ξ, z). since the direction of fluid flow in the pipe does not change, the z-direction of the Cartesian and bipolar coordinate systems does not change.
z is z formula three
The scale factor of the coordinates (ξ, z) in the bipolar coordinate system is as shown in formula four to formula six:
In the above-mentioned formula,
wherein D is the diameter of the pipeline and has the unit of meter (m).
According to the coordinate relation between the Cartesian coordinate system and the bipolar coordinate system, the fluid flow area under the Cartesian coordinate system is converted into a regular rectangular calculation area under the bipolar coordinate system through bipolar coordinate transformation. The partial derivative formula of the cartesian coordinate system converted into the bipolar coordinate system is as formula seven to formula ten:
for convenience of calculation, c is taken as cosh η cos ξ -1, s is sinh η sin ξ, c2+s2＝(coshη-cosξ)2。
Wherein chi is a gauge coefficient representing ξ direction and reflects the density degree of grid lines in ξ direction, gamma is a gauge coefficient representing η direction and reflects the density degree of grid lines in η direction, β represents the orthogonality degree of ξ direction and η direction, 0 represents orthogonality, J represents the expansion degree of a control volume on bipolar coordinates, dV is Jd ξ d η, and dV represents the volume of the control volume in a Cartesian coordinate system.
Since the physical flow of the fluid in the pipe occurs in a cartesian coordinate system, and a bipolar coordinate system is a calculation plane, the control equations for the fluid in the pipe need to be established in the bipolar coordinate system, and the derivative relationships of the scalars between the physical plane and the calculation plane are given as formula fifteen to formula eighteen:
the formula nineteen can be obtained according to the formulas fifteen to eighteen:
in the above equations fifteen to nineteen, phi may represent any variable, i.e. the pressure gradient, the velocity field, the turbulent kinetic energy of the pipe section, the specific dissipation ratio of the turbulent kinetic energy, the turbulent viscosity, the turbulent energy dissipation ratio, and the like.
According to the first formula to the nineteenth formula, the parameters of the pipeline and the object parameters of the fluid in the pipeline under the Cartesian coordinate system input by a user can be converted into the parameters of the pipeline and the object parameters of the fluid in the pipeline under the bipolar coordinate system, and the parameters of the pipeline and the object parameters of the fluid in the pipeline are obtained.
S202, acquiring a preset pressure gradient and a preset speed field.
S203, determining an effective value of turbulent kinetic energy, an effective value of specific dissipation ratio of turbulent kinetic energy and an effective value of turbulent viscosity according to a turbulent model equation, parameters of the pipeline, object parameters of fluid in the pipeline, the preset pressure gradient and the preset velocity field.
In this embodiment, when the fluid in the pipeline is in a turbulent state (reynolds number is greater than 2000), a turbulent model equation needs to be introduced to solve the turbulent parameters, and the solved turbulent parameters interact with the flow field of the fluid in the pipeline, so that the distribution rule of the flow field can be influenced, and the physical rule of the turbulent flow is met. Wherein the turbulence parameters comprise an effective value of turbulence kinetic energy, an effective value of specific dissipation ratio of turbulence kinetic energy, an effective value of turbulence viscosity, and the like. The turbulence model equation is as the formula twenty-one and the formula twenty-three.
The turbulent kinetic energy equation under the Cartesian coordinate system is shown as the formula twenty:
the turbulent kinetic energy equation in bipolar coordinates is as in twenty-one:
the specific dissipation ratio equation of the turbulent kinetic energy in the Cartesian coordinate system is as shown in the formula twenty-two:
the specific dissipation ratio equation of turbulent kinetic energy in bipolar coordinates is as shown in the formula twenty three:
turbulent viscosity is calculated as the formula twenty-four:
ε＝β2omega k formula twenty five
In the above formulas twenty to twenty-five, w represents the velocity field of the fluid in the pipe, and the unit is meter per second (m/s); j represents the degree of expansion of the control volume on bipolar coordinates; μ represents the viscosity of the fluid itself in the conduit in pascal seconds (Pa · s); mu.stRepresents the turbulent viscosity of the fluid in the pipeline, and has the unit of Pascal seconds (Pa.s); ρ represents the fluid density in the pipe in kilograms per cubic meter (Kg/m)3) (ii) a k represents the kinetic energy of fluid turbulence in the pipe in square meters per square second (m)2/s2) (ii) a ω represents the specific dissipation ratio of the kinetic energy of the fluid turbulence in the pipe, in units of per second (1/s); ε represents the turbulent energy dissipation ratio in unitsIs square meter per cubic second (m)2s-3)；
D represents the diameter of the pipeline in meters (m); β1＝0.075，β2＝0.09，σ1＝05，σ2Each represents a coefficient in the turbulence control equation, 0.5.
And acquiring an effective value of turbulent kinetic energy, an effective value of specific dissipation ratio of turbulent kinetic energy and an effective value of turbulent viscosity according to the preset pressure gradient and the preset velocity field acquired in the step S202, the equation formula twenty-one and the equation twenty-three of the turbulent model, the parameters of the pipeline and the object parameters of the fluid in the pipeline. Wherein the effective value of the turbulent viscosity is the turbulent viscosity generated after the fluid flow has the turbulent change.
And S204, obtaining a calculated velocity field according to the strain parameter and the momentum equation of the drag reducer added into the fluid.
In this embodiment, in order to reduce the frictional resistance of the fluid flowing in the pipeline, a drag reducer is added to the fluid in the pipeline, and thus a strain parameter of the drag reducer is introduced.
For the convenience of research, the fluid flow in the x and y directions in the coordinate system is ignored, and only the velocity distribution rule in the z direction is considered. Based on newton's second law, the equation of momentum in the z direction in the coordinate system can be listed.
The momentum equation in the z direction under the Cartesian coordinate system is shown as twenty-six:
the momentum equation in the z direction under the bipolar coordinate system is shown as twenty-seven:
in a twenty-sixth formula and a twenty-seventh formula, w represents a velocity field of fluid in the pipeline, and the unit is meter per second (m/s);
the pressure gradient of the flowing direction of the fluid in the pipeline is expressed in units of pascal per meter (Pa/m), lambda represents the relaxation time constant of the viscoelasticity characteristic of the solution and is expressed in units of seconds(s), η represents the contribution of the additive to the viscosity at the time of zero shearing stress and is expressed in units of pascal seconds (Pa.s), α (0 < α < 1) represents the migration factor of the viscoelasticity drag reduction solution and is a key factor for determining the extensional viscosity of the solution, and czzThe strain in the z direction on the z surface of the control body is expressed in units of kilograms per meter per second (kg/(m & s)); c. CxzThe strain in the z direction on the x surface of the control body is expressed in units of kilograms per meter per second (kg/(m & s)); c. CyzThe strain in the z direction on the y surface of the control body is expressed in units of kilograms per meter per second (kg/(m · s));
d represents the diameter of the pipeline and has the unit of meter (m); μ represents the viscosity of the fluid itself in the conduit in pascal seconds (Pa · s); mu.stRepresents the turbulent viscosity of the fluid in the pipeline, and has the unit of Pascal seconds (Pa.s); ρ represents the fluid density in the pipe in kilograms per cubic meter (Kg/m)3) (ii) a g represents the acceleration of gravity in square meters per square second (m)2/s2) Theta is a pipe inclination angle and is expressed in degrees, chi is a gauge coefficient which shows ξ direction and reflects the density degree of grid lines in ξ direction, gamma is a gauge coefficient which shows η direction and reflects the density degree of grid lines in η direction, β shows the orthogonality degree of ξ direction and η direction, 0 shows orthogonality, J shows the expansion degree of control volume on bipolar coordinates, dV is Jd ξ d η, and dV shows the volume of the control volume in Cartesian coordinates.
And acquiring a calculated speed field according to the drag reducer strain parameter and a momentum equation formula twenty-six, wherein the calculated speed field is the speed field of the current pipeline section.
S205, outputting the preset pressure gradient, the calculated velocity field, the effective value of turbulent kinetic energy, the effective value of specific dissipation rate of turbulent kinetic energy and the effective value of turbulent viscosity.
In this embodiment, the preset pressure gradient, the calculated velocity field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation ratio of the turbulent kinetic energy, the effective value of the turbulent viscosity, and the like obtained in the above steps may be sent to a corresponding display device, and the preset pressure gradient, the calculated velocity field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation ratio of the turbulent kinetic energy, the effective value of the turbulent viscosity, and the like may be displayed through the display device. Or directly displaying the preset pressure gradient, the calculated velocity field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity through self equipment. The display device may be a terminal device, such as a computer, a mobile phone, and the like, which is not limited in this application.
In the embodiment, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity are determined according to the diameter of the input pipeline, the flow rate of the pipeline inlet, the density of the fluid, the viscosity of the fluid, the preset pressure gradient and the preset velocity field as well as the turbulent equation; then, obtaining a calculated velocity field according to a strain parameter and a momentum equation of the drag reducer added into the fluid; and then outputting the preset pressure gradient, the calculated speed field, the effective value of turbulent kinetic energy, the effective value of specific dissipation rate of turbulent kinetic energy and the effective value of turbulent viscosity, predicting the flow condition of the fluid in the pipeline, effectively analyzing the drag reduction rate of the pipe flow under different flow rates and the change of the physical property of the drag reduction agent, the change rule of the pressure gradient in the pipeline and the distribution condition of the flow field, and improving the analysis efficiency.
Fig. 5 is a schematic flow chart of a method for predictive analysis of a cross-sectional flow of a pipeline according to another embodiment of the present application, where as shown in fig. 5, the method according to an embodiment of the present application may include:
s501, obtaining input parameters of a pipeline and object parameters of fluid in the pipeline, wherein the parameters of the pipeline comprise the diameter of the pipeline and the flow of an inlet of the pipeline, and the object parameters of the fluid comprise the density of the fluid and the viscosity of the fluid.
And S502, acquiring a preset pressure gradient and a preset speed field.
The specific implementation process of S501-S502 may refer to the related description in the embodiment shown in fig. 2, and is not described herein again.
S503, determining an initial value of turbulent flow energy and an initial value of specific dissipation ratio of turbulent flow kinetic energy according to a turbulent flow model equation, parameters of the pipeline and object parameters of fluid in the pipeline, the preset pressure gradient and the preset velocity field.
In this embodiment, when the fluid in the pipeline is in a turbulent state (reynolds number is greater than 2000), a turbulent model equation needs to be introduced to solve the turbulent parameters, and the solved turbulent parameters interact with the flow field of the fluid in the pipeline, so that the distribution rule of the flow field can be influenced, and the physical rule of the turbulent flow is met. And acquiring an initial value of the turbulent kinetic energy and an initial value of the specific dissipation rate of the turbulent kinetic energy according to the turbulent model equation formula twenty-one, the formula twenty-three, the preset pressure gradient and the preset velocity field.
S504, determining an initial value of the turbulent flow viscosity according to the initial value of the turbulent flow kinetic energy, the initial value of the specific dissipation rate of the turbulent flow kinetic energy and the density of the fluid.
In this embodiment, the initial value of the turbulent viscosity is obtained by using twenty-four equations according to the initial value of the turbulent kinetic energy and the initial value of the specific dissipation ratio of the turbulent kinetic energy obtained in S503 and the input fluid density parameter.
And S505, determining an effective value of the turbulent kinetic energy, an effective value of the specific dissipation rate of the turbulent kinetic energy and an effective value of the turbulent viscosity according to the initial value of the turbulent viscosity, the initial value of the turbulent kinetic energy, the initial value of the specific dissipation rate of the turbulent kinetic energy and the turbulent model equation.
In this embodiment, according to the initial value of the turbulence viscosity, the initial value of the turbulence kinetic energy, the initial value of the specific dissipation ratio of the turbulence kinetic energy, the equation twenty-one of the turbulence model equation, and the equation twenty-three acquired in S503 and S504, the effective value of the turbulence kinetic energy, the effective value of the specific dissipation ratio of the turbulence kinetic energy, and the effective value of the turbulence viscosity are acquired.
The specific implementation process of the turbulence equation may refer to the related description in the embodiment shown in fig. 1, and is not described herein again.
As shown in fig. 5, the embodiment further includes:
and S506, determining a strain parameter of the drag reducer added into the fluid according to the constitutive equation.
Drag reducing agents may or may not be added to the fluid according to the needs of the user, for example, the drag reducing agent is added in this embodiment. The constitutive equation of Giesekus viscoelastic non-Newtonian body is used as the constitutive equation of the drag reducer, and the tensor form is as the formula twenty-eight:
wherein tau is a viscoelasticity additional stress tensor with the unit of Pa (Pa), lambda is a relaxation time constant of the viscoelasticity characteristic of the solution with the unit of second(s), α (0 < α < 1) is a migration factor of the viscoelasticity drag reduction solution and is a key factor for determining the extensional viscosity of the solution, η is the contribution of the additive to the viscosity with zero shear stress with the unit of Pascal second (Pa.s), and u is a velocity vector.
For convenience of research, in the present embodiment, only the main flow direction of the fluid in the pipeline is considered, and the influence of other flow directions is ignored, and the main flow direction of the fluid in the pipeline is the velocity field direction of the fluid, so that only the flow law in the velocity field direction of the fluid in the pipeline needs to be considered.
The constitutive equation under the simplified Cartesian coordinate system is as the formula twenty-nine:
the constitutive equation under the bipolar coordinate system is as formula thirty:
twenty-ninth formula and thirty formula, wherein w represents velocity field of fluid in pipeline, unit is meter per second (m/s), lambda represents relaxation time constant of viscoelasticity characteristic of solution, unit is second(s), η represents contribution of additive to viscosity at zero shearing stress, unit is Pascal second (Pa.s), α (0 < α < 1) represents migration factor of viscoelasticity drag reduction solution, which is key factor for determining solution extensional viscosity, czzThe strain in the z direction on the z surface of the control body is expressed in units of kilograms per meter per second (kg/(m & s)); c. CxzThe strain in the z direction on the x surface of the control body is expressed in units of kilograms per meter per second (kg/(m & s)); c. CyzThe strain in the z direction on the y surface of the control body is expressed in units of kilograms per meter per second (kg/(m · s));
d represents the pipe diameter in meters (m).
Obtaining the strain parameter c of the drag reducer added in the fluid according to the formula thirtyzz，cxz，cyz。
And S507, obtaining a calculated speed field according to the strain parameter and the momentum equation of the drag reducer added into the fluid.
The strain parameter c of the drag reducer added to the fluid solved according to the constitutive equation in S506zz，cxz，cyzAnd the momentum equation stated in S204, the calculatedA velocity field.
In some embodiments, the embodiments further include S508-S510:
and S508, judging whether the difference value between the calculated speed field and the preset speed field is smaller than a second preset difference value.
In this embodiment, it is determined whether the difference between the calculated velocity field obtained in S507 and the preset velocity field is smaller than a second preset difference.
Wherein the second preset difference value may be determined according to a difference between the acquired calculated velocity field and the preset velocity field. For example, the difference may be zero or a value smaller than zero.
S509, if the difference value between the calculated speed field and the preset speed field is smaller than a second preset difference value, outputting the calculated speed field.
In this embodiment, it is determined whether a difference between the calculated velocity field and the preset velocity field is smaller than a second preset difference, and if the difference between the calculated velocity field and the preset velocity field is smaller than the second preset difference, the currently calculated velocity field is output.
And S510, if the difference value between the calculated speed field and the preset speed field is larger than or equal to a second preset difference value, changing the value of the preset speed field into the value of the calculated speed field.
In this embodiment, it is determined whether the difference between the calculated velocity field and the preset velocity field is smaller than a second preset difference, if the difference between the calculated velocity field and the preset velocity field is not smaller than the second preset difference, that is, the difference between the calculated velocity field and the preset velocity field is greater than or equal to the second preset difference, the value of the preset velocity field is changed to the value of the calculated velocity field, then steps S502-S507 are executed to obtain the turbulence viscosity again, the value of the currently calculated velocity field is obtained according to the momentum equation, the turbulence equation and the constitutive equation, and the value of the currently calculated velocity field is output.
In some embodiments, the embodiments further include S511-S514:
and S511, determining the cross-sectional flow of the pipeline according to the calculated velocity field and the mass conservation equation.
And acquiring the cross-sectional flow of the pipeline cross section according to the calculated velocity field value acquired in the step and the mass conservation equation of the fluid.
In this embodiment, since the product oil in the pipeline is a non-compressible fluid, the flow rate of the fluid in the pipeline is conserved, and the flow rate of the fluid on the cross section of the pipeline remains unchanged. Wherein, the conservation of mass equation is shown as formula thirty-one:
g ═ ρ wdA formula thirty-one
In the thirty-first formula, G represents the mass flow rate through the current cross-section in kilograms per second (kg/s); w represents the velocity in the z-direction of each control volume within the grid in meters per second (m/s); ρ represents the fluid density in kilograms per cubic meter (Kg/m3) of the fluid in the pipe, A represents the area of the control unit in square meters (m)2)。
And acquiring the cross-sectional flow of the pipeline cross section according to the calculated velocity field value acquired in the step S508 and the mass conservation equation of the fluid.
S512, judging whether the difference value between the cross-section flow of the pipeline and the input flow of the pipeline inlet is smaller than a first preset difference value.
S513, if the difference value between the cross-section flow of the pipeline and the flow of the pipeline inlet is smaller than a first preset difference value, outputting the preset pressure gradient, the calculated velocity field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity.
In this embodiment, the difference value between the cross-sectional flow of the pipeline obtained in S509 and the input flow of the pipeline inlet is determined, and if the difference value between the cross-sectional flow of the pipeline and the input flow of the pipeline inlet is smaller than a first preset difference value, the preset pressure gradient, the calculated velocity field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy, and the effective value of the turbulent viscosity are output.
For example, fig. 6-7 show the distribution of the fluid velocity field over a section of a pipe, the effective values of the turbulent kinetic energy, the specific dissipation ratio of the turbulent kinetic energy, and the effective values of the turbulent viscosity, as shown in fig. 8, 9, and 10, respectively. Wherein, the directions represented by the contour lines 1-2-3-4-5-6-7-8-9-10-11 in the figures 6 and 8-10 are from the center of the pipeline to the pipe wall in sequence. Fig. 6 is a distribution diagram of the calculated pipeline fluid section velocity field contour line, according to an embodiment of the present application, it can be seen from fig. 6 that the velocity field values of the fluid in the pipeline sequentially from the center of the pipeline to the pipe wall are: 0.55m/s, 0.5m/s, 0.45m/s, 0.4m/s, 0.35m/s, 0.3m/s, 0.25m/s, 0.2m/s, 0.15m/s, 0.1m/s and 0.05 m/s. The velocity field values show that the velocity value at the center of the pipeline is large, the velocity value at the pipe wall is small, and the turbulence rule of fluid in the pipeline is met. FIG. 7 is a distribution diagram of velocity field at the center line of a cross section of a pipeline fluid according to an embodiment of the present application, wherein the velocity at the cross section of the center line is in a parabolic distribution, as shown in FIG. 7. Fig. 8 is a distribution diagram of the effective value contour line of the turbulent kinetic energy provided by an embodiment of the present application, as shown in fig. 8, the effective value of the turbulent kinetic energy sequentially from the center of the pipe to the pipe wall: 0.0005m2/s2、0.0006m2/s2、0.0007m2/s2、0.0008m2/s2、0.0009m2/s2、0.001m2/s2、0.0011m2/s2、0.0011m2/s2、0.001m2/s2、0.0009m2/s2And 0.0008m2/s2. Fig. 9 is a distribution diagram of an effective value contour line of the specific dissipation ratio of the turbulent kinetic energy provided by an embodiment of the present application, as shown in fig. 9, the effective value of the specific dissipation ratio of the turbulent kinetic energy sequentially from the center of the pipe to the pipe wall is: 42.16971/s, 56.23411/s, 74.98941/s, 1001/s, 133.3521/s, 177.8281/s, 237.1371/s, 316.2281/s, 562.3411/s, 749.8941/s and 10001/s. FIG. 10 is a plot of the effective value contour of the turbulence viscosity as provided in one embodiment of the present application, as shown in FIG. 10The effective value of the flow viscosity from the center of the pipeline to the pipe wall is as follows in sequence: 0.012 pas, 0.011 pas, 0.01 pas, 0.009 pas, 0.008 pas, 0.007 pas, 0.006 pas, 0.005 pas, 0.004 pas, 0.003 pas, and 0.002 pas.
Wherein the first preset value can be determined according to a difference between a cross-sectional flow rate of the pipeline and an input flow rate of the pipeline inlet. In the embodiment of the present application, the first preset value may be 10-4。
And S514, if the difference value between the cross-sectional flow of the pipeline and the flow of the pipeline inlet is larger than or equal to a first preset difference value, changing the value of the preset pressure gradient according to a dichotomy.
In this embodiment, a difference value between the cross-sectional flow of the pipeline obtained in S509 and the input flow of the pipeline inlet is determined, and if the difference value between the cross-sectional flow of the pipeline and the input flow of the pipeline inlet is greater than a first preset difference value, the preset pressure gradient value is determined again according to a bisection method change. And then according to the pressure gradient value, re-acquiring the preset pressure gradient, the calculated velocity field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation ratio of the turbulent kinetic energy and the effective value of the turbulent viscosity, and executing the steps S502-S509 in the concrete implementation process.
The dichotomy is specifically realized by the following steps:
1) the difference value function between the cross-sectional flow of the pipeline and the inlet flow of the pipeline can be as follows: f (x)p)＝|Gc-G |. Wherein G represents the set flow rate in kilograms per cubic meter (Kg/m)3)；GcRepresents the calculated flow rate in kilograms per cubic meter (Kg/m)3)，xpThe pressure gradient of the fluid in the pipeline is expressed, and the unit is pascal per meter (Pa/m); .
2) Assuming a pressure gradient range [ a, b ]]Then the pressure gradient at the midpoint
The interval is divided into two.
3) According to the midpoint pressure gradient x0The momentum equation, the turbulence equation and the constitutive equation are used for obtaining the section flow G of the pipeline under the pressure gradientc. Calculating a difference value f (x) between the cross-sectional flow of the pipeline and the inlet flow of the pipeline0) If less than 10-4Then x0Is the pressure gradient value to be output.
4) If f (a) f (x)0) If > 0, x is larger than x0B) with x0Replacing a; if f (a) f (x)0) If < 0, x is in the range of (a, x)0) With x0Instead of b.
5) If | Gc-G|＜10-4The dichotomy calculation terminates. When x is equal to x0，x0Is the pressure gradient at the inlet flow of the pipe.
In this embodiment, an initial value of turbulent flow energy, an initial value of specific dissipation ratio of turbulent flow kinetic energy, and an initial value of turbulent flow viscosity are obtained by using the diameter of the pipe, the flow rate at the pipe inlet, the density of the fluid, the viscosity of the fluid, a preset pressure gradient, a preset velocity field, and a turbulent flow equation; then obtaining an effective value of the turbulent flow kinetic energy, an effective value of the specific dissipation rate of the turbulent flow kinetic energy and an effective value of the turbulent flow viscosity according to the initial value of the turbulent flow viscosity, the initial value of the turbulent flow kinetic energy, the initial value of the specific dissipation rate of the turbulent flow kinetic energy and the turbulent flow model equation; then according to the constitutive equation, obtaining a strain parameter of the drag reducer added in the fluid; then, acquiring a calculated velocity field according to a strain parameter and a momentum equation of the drag reducer added into the fluid; judging whether the difference value between the calculated speed field and the preset speed field is smaller than a second preset difference value or not, outputting the calculated speed field, finally obtaining the section flow of the pipeline according to the calculated speed field and a mass conservation equation, judging the difference value between the section flow of the pipeline and the input flow of the pipeline inlet, and outputting the preset pressure gradient, the calculated speed field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity. The method mainly considers the influences of adding a drag reducer in a fluid and a long-distance transportation pipeline, can ensure the flow state on the long-distance transportation pipeline of the finished oil on the basis of coupling a turbulence model equation and an constitutive equation, has better orthogonality by applying a bipolar coordinate system in the model, can predict and obtain the velocity distribution, the turbulence parameters and the pressure gradient of the circular section of the long-distance pipeline through volume flow conservation, can effectively guide the operation of the long-distance transportation pipeline of the finished oil, and improves the analysis efficiency.
Fig. 11 is a schematic structural diagram of a device for predictive analysis of a cross-sectional flow of a pipeline according to an embodiment of the present application, and as shown in fig. 11, a device 1100 according to an embodiment of the present application may include: a first acquiring module 1110, a second acquiring module 1120, a first processing module 1130, a second processing module 1140, and an output module 1150.
The first obtaining module 1110 is configured to obtain input parameters of a pipeline and object parameters of fluid in the pipeline, where the parameters of the pipeline include a diameter of the pipeline and a flow rate at an inlet of the pipeline, and the object parameters of the fluid include a density of the fluid and a viscosity of the fluid.
The second obtaining module 1120 is configured to obtain a preset pressure gradient and a preset velocity field.
The first processing module 1130 is configured to determine an effective value of turbulent kinetic energy, an effective value of specific dissipation ratio of turbulent kinetic energy, and an effective value of turbulent viscosity according to a turbulent model equation, parameters of the pipe, and object parameters of fluid in the pipe, the preset pressure gradient, and the preset velocity field.
The second processing module 1140 is configured to obtain a calculated velocity field according to a strain parameter and a momentum equation of a drag reducer added to the fluid.
The output module 1150 is configured to output the preset pressure gradient, the calculated velocity field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation ratio of the turbulent kinetic energy, and the effective value of the turbulent viscosity.
In some embodiments, the first processing module 1130 is specifically configured to:
and determining an initial value of turbulent flow energy and an initial value of specific dissipation ratio of turbulent flow kinetic energy according to a turbulent flow model equation, parameters of the pipeline and object parameters of fluid in the pipeline, the preset pressure gradient and the preset velocity field.
And determining an initial value of the turbulent viscosity according to the initial value of the turbulent kinetic energy, the initial value of the specific dissipation ratio of the turbulent kinetic energy and the density of the fluid.
And determining the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity according to the initial values of the turbulent viscosity, the turbulent kinetic energy and the turbulent model equation.
In some embodiments, the apparatus 1100, further comprises: a third processing module 1160.
The third processing module 1160 is configured to determine a strain parameter of a drag reducer added to the fluid according to a constitutive equation.
In some embodiments, before the output module 1150, the method further includes: a fourth processing module 1170.
And the fourth processing module 1170 is configured to determine the cross-sectional flow of the pipeline according to the calculated velocity field and the mass conservation equation.
The output module 1150 is specifically configured to:
and if the difference value between the cross-section flow of the pipeline and the flow of the pipeline inlet is smaller than a first preset difference value, outputting the preset pressure gradient, the calculated speed field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity.
The output module 1150 is further configured to:
and if the difference value between the cross-sectional flow of the pipeline and the flow of the pipeline inlet is larger than or equal to a first preset difference value, changing the value of the preset pressure gradient according to a dichotomy.
In some embodiments, before the output module 1150 outputs the calculated velocity field, it further includes: a decision block 1180.
The determining module 1180 is configured to determine whether a difference between the calculated velocity field and the preset velocity field is smaller than a second preset difference.
The output module 1150 is specifically configured to:
and if the difference value between the calculated speed field and the preset speed field is smaller than a second preset difference value, outputting the calculated speed field.
In some embodiments, the output module 1150 is further configured to:
and if the difference value between the calculated speed field and the preset speed field is greater than or equal to a second preset difference value, changing the value of the preset speed field into the value of the calculated speed field.
The apparatus of this embodiment may be configured to implement the technical solutions of the above method embodiments, and the implementation principle and the technical effect are similar, which are not described herein again.
Fig. 12 is a schematic structural diagram of an electronic device according to an embodiment of the present application, and as shown in fig. 12, an electronic device 1200 according to this embodiment may include: memory 1210, processor 1220.
A memory 1210 for storing program instructions;
a processor 1220, configured to call and execute the program instructions in the memory, to perform:
the method comprises the steps of obtaining input parameters of a pipeline and object parameters of fluid in the pipeline, wherein the parameters of the pipeline comprise the diameter of the pipeline and the flow rate of an inlet of the pipeline, and the object parameters of the fluid comprise the density of the fluid and the viscosity of the fluid.
And acquiring a preset pressure gradient and a preset speed field.
And determining the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity according to a turbulent model equation, the parameters of the pipeline and the object parameters of the fluid in the pipeline, the preset pressure gradient and the preset velocity field.
And obtaining a calculated velocity field according to the strain parameter and the momentum equation of the drag reducer added into the fluid.
And outputting the preset pressure gradient, the calculated speed field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity.
Optionally, the processor 1220 is specifically configured to:
and determining an initial value of turbulent flow energy and an initial value of specific dissipation ratio of turbulent flow kinetic energy according to a turbulent flow model equation, parameters of the pipeline and object parameters of fluid in the pipeline, the preset pressure gradient and the preset velocity field.
And determining an initial value of the turbulent viscosity according to the initial value of the turbulent kinetic energy, the initial value of the specific dissipation ratio of the turbulent kinetic energy and the density of the fluid.
And determining the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity according to the initial values of the turbulent viscosity, the turbulent kinetic energy and the turbulent model equation.
Optionally, the processor 1220 is further configured to:
determining a strain parameter of a drag reducer added to the fluid according to a constitutive equation.
Optionally, before outputting the preset pressure gradient, the calculated velocity field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation ratio of the turbulent kinetic energy, and the effective value of the turbulent viscosity, the processor 1220 is further configured to:
and determining the cross-sectional flow of the pipeline according to the calculated velocity field and the mass conservation equation.
The processor 1220 is specifically configured to:
and if the difference value between the cross-section flow of the pipeline and the flow of the pipeline inlet is smaller than a first preset difference value, outputting the preset pressure gradient, the calculated speed field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity.
Optionally, the processor 1220 is further configured to:
and if the difference value between the cross-sectional flow of the pipeline and the flow of the pipeline inlet is larger than or equal to a first preset difference value, changing the value of the preset pressure gradient according to a dichotomy.
Optionally, before outputting the calculated velocity field, the processor 1220 is further configured to:
and judging whether the difference value between the calculated speed field and the preset speed field is smaller than a second preset difference value.
The processor 1220 is specifically configured to:
and if the difference value between the calculated speed field and the preset speed field is smaller than a second preset difference value, outputting the calculated speed field.
Optionally, the processor 1220 is further configured to:
and if the difference value between the calculated speed field and the preset speed field is greater than or equal to a second preset difference value, changing the value of the preset speed field into the value of the calculated speed field.
The electronic device of this embodiment may be configured to execute the technical solutions of the above method embodiments, and the implementation principle and the technical effect are similar, which are not described herein again.
Fig. 13 is a schematic structural diagram of an electronic device according to another embodiment of the present application. Referring to fig. 13, electronic device 1300 includes a processing component 1322, which further includes one or more processors, and memory resources, represented by memory 1332, for storing instructions, such as application programs, that may be executed by processing component 1322. The application programs stored in memory 1332 may include one or more modules that each correspond to a set of instructions. Further, processing component 1322 is configured to execute instructions to carry out aspects of the various method embodiments described above.
The electronic device 1300 may also include a power component 1326 configured to perform power management for the electronic device 1300, a wired or wireless network interface 1350 configured to connect the electronic device 1300 to a network, and an input-output (I/O) interface 1358. The electronic device 1300 may operate based on an operating system, such as Windows Server, Mac OS XTM, UnixTM, LinuxTM, FreeBSDTM, or the like, stored in the memory 1332.
A non-transitory computer readable storage medium having instructions therein which, when executed by a processor of a server, enable the server to perform the aspects of any of the method embodiments described above.
Those of ordinary skill in the art will understand that: all or a portion of the steps of implementing the above-described method embodiments may be performed by hardware associated with program instructions. The program may be stored in a computer-readable storage medium. When executed, the program performs steps comprising the method embodiments described above; and the aforementioned storage medium includes: various media capable of storing program codes, such as a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, and an optical disk.
Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.
Claims (10)
1. A method for predictive analysis of flow across a pipeline, comprising:
acquiring input parameters of a pipeline and object parameters of fluid in the pipeline, wherein the parameters of the pipeline comprise the diameter of the pipeline and the flow rate of an inlet of the pipeline, and the object parameters of the fluid comprise the density of the fluid and the viscosity of the fluid;
acquiring a preset pressure gradient and a preset speed field;
determining an effective value of turbulent kinetic energy, an effective value of specific dissipation ratio of turbulent kinetic energy and an effective value of turbulent viscosity according to a turbulent model equation, parameters of the pipeline, object parameters of fluid in the pipeline, the preset pressure gradient and the preset velocity field;
obtaining a calculated velocity field according to a strain parameter and a momentum equation of a drag reducer added into the fluid;
and outputting the preset pressure gradient, the calculated speed field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity.
2. The method of claim 1, wherein said determining an effective value of turbulent kinetic energy, an effective value of specific dissipation ratio of turbulent kinetic energy, an effective value of turbulent viscosity from a turbulence model equation, parameters of said pipe and object parameters of fluid in said pipe, said preset pressure gradient and said preset velocity field comprises:
determining an initial value of turbulent flow energy and an initial value of specific dissipation ratio of turbulent flow kinetic energy according to a turbulent flow model equation, parameters of the pipeline and object parameters of fluid in the pipeline, the preset pressure gradient and the preset velocity field;
determining an initial value of the turbulent viscosity according to the initial value of the turbulent kinetic energy, the initial value of the specific dissipation ratio of the turbulent kinetic energy and the density of the fluid;
and determining the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity according to the initial values of the turbulent viscosity, the turbulent kinetic energy and the turbulent model equation.
3. The method of claim 1, further comprising:
determining a strain parameter of a drag reducer added to the fluid according to a constitutive equation.
4. The method of claim 1, wherein outputting the preset pressure gradient, the calculated velocity field, the effective value of turbulent kinetic energy, the effective value of specific dissipation ratio of turbulent kinetic energy, and the effective value of turbulent viscosity further comprises:
determining the cross-sectional flow of the pipeline according to the calculated velocity field and the mass conservation equation;
outputting the preset pressure gradient, the calculated velocity field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation ratio of the turbulent kinetic energy and the effective value of the turbulent viscosity, comprising:
and if the difference value between the cross-section flow of the pipeline and the flow of the pipeline inlet is smaller than a first preset difference value, outputting the preset pressure gradient, the calculated speed field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity.
5. The method of claim 4, further comprising:
and if the difference value between the cross-sectional flow of the pipeline and the flow of the pipeline inlet is larger than or equal to a first preset difference value, changing the value of the preset pressure gradient according to a dichotomy.
6. The method of any of claims 1-3, further comprising, prior to outputting the calculated velocity field:
judging whether the difference value between the calculated speed field and the preset speed field is smaller than a second preset difference value or not;
the output calculated velocity field includes:
and if the difference value between the calculated speed field and the preset speed field is smaller than a second preset difference value, outputting the calculated speed field.
7. The method of claim 6, further comprising:
and if the difference value between the calculated speed field and the preset speed field is greater than or equal to a second preset difference value, changing the value of the preset speed field into the value of the calculated speed field.
8. A pipe cross-sectional flow predictive analysis apparatus, comprising:
the system comprises a first acquisition module, a second acquisition module and a third acquisition module, wherein the first acquisition module is used for acquiring input parameters of a pipeline and object parameters of fluid in the pipeline, the parameters of the pipeline comprise the diameter of the pipeline and the flow rate of an inlet of the pipeline, and the object parameters of the fluid comprise the density of the fluid and the viscosity of the fluid;
the second acquisition module is used for acquiring a preset pressure gradient and a preset speed field;
the first processing module is used for determining an effective value of turbulent kinetic energy, an effective value of specific dissipation ratio of turbulent kinetic energy and an effective value of turbulent viscosity according to a turbulent model equation, parameters of the pipeline and object parameters of fluid in the pipeline, the preset pressure gradient and the preset velocity field;
the second processing module is used for obtaining a calculated velocity field according to a strain parameter and a momentum equation of a drag reducer added into the fluid;
and the output module is used for outputting the preset pressure gradient, the calculated speed field, the effective value of the turbulent kinetic energy, the effective value of the specific dissipation rate of the turbulent kinetic energy and the effective value of the turbulent viscosity.
9. An electronic device, comprising:
a memory for storing program instructions;
a processor for calling and executing program instructions in said memory to perform the pipe cross-section flow predictive analysis method of any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that the computer storage medium stores a computer program which, when executed by a processor, implements the pipe cross-sectional flow predictive analysis method of any one of claims 1 to 7.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN112610215A (en) * | 2020-12-15 | 2021-04-06 | 金奥深海装备技术(深圳)有限责任公司 | Mining parameter determination method of gas lift method, terminal and storage medium |
| CN113358526A (en) * | 2021-04-26 | 2021-09-07 | 中国矿业大学 | Hydrate slurry flow pressure drop prediction method and system based on energy dissipation theory |
| CN113358526B (en) * | 2021-04-26 | 2022-07-12 | 中国矿业大学 | Hydrate slurry flow pressure drop prediction method and system based on energy dissipation theory |
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