A flow equalization runner design method based on outlet pressure regulation

Abstract

The application discloses a kind of based on outlet pressure regulation's current sharing flow passage design method, for the problem of high calculation cost, experience dependence and unable to guarantee flow uniformity of existing multi-outlet flow distribution flow passage design method, the method proposes first through the explicit regulation of outlet pressure boundary condition, guide flow passage internal flow state to the uniform distribution direction evolution;After obtaining uniform flow distribution state, then based on the dynamic pressure distribution in the uniform flow field directly extracts dynamic pressure contour or equivalent surface as flow passage boundary.The application only needs limited number of flow field numerical analysis to obtain the flow passage structure still has highly uniform flow distribution performance under the condition of uniform outlet pressure, without relying on experience or carrying out multiple rounds of geometric iteration, significantly improve the design efficiency and engineering applicability of multi-outlet fluid distribution system.

Description

Technical Field

[0001] This invention relates to the field of fluid dynamics design and flow channel topology optimization, and in particular to a flow equalization channel design method based on outlet pressure regulation, which optimizes the flow distribution at the flow channel outlet through pressure boundary intervention and physical feature extraction. Background Technology

[0002] In aerospace, automotive engineering, and chemical equipment fields, engineering structures for distributing and uniformly supplying fluids are widely used. Examples include cooling channels in aero-engine and aircraft thermal management systems, reaction gas and coolant distribution manifolds in automotive fuel cell and power battery systems, and multi-branch flow channel structures in chemical process equipment and compact heat exchangers. These systems typically have multiple outlets or parallel branches, and the uniformity of flow distribution directly affects heat exchange efficiency, reaction consistency, and system operational stability. Therefore, achieving uniform fluid distribution under complex geometries and multiple outlet conditions is a key common problem in fluid distribution system design.

[0003] Existing flow channel design methods mainly rely on engineering experience or numerical optimization techniques based on parametric models. In engineering practice, the outlet flow distribution is typically improved by adjusting the flow channel cross-sectional dimensions, branch layout, or local structural forms, and then repeatedly verifying the results using flow field numerical simulations. However, these methods are highly dependent on the designer's experience, and the design process lacks unified theoretical guidance and deterministic rules. When the flow channel structure becomes complex or the number of outlets increases, the design efficiency decreases significantly, making it difficult to quickly obtain a flow channel configuration that meets the requirements for uniform distribution.

[0004] To improve the automation of design, some studies have introduced optimization methods such as response surface methodology and genetic algorithms to design flow channel structures. These methods typically approximate the target flow distribution through large-sample calculations and multiple rounds of iterative searches. Although they reduce human intervention to some extent, they still rely on costly iterative calculations, resulting in low computational efficiency and long design cycles, which is not conducive to rapid design and parameter adjustment in engineering applications.

[0005] Furthermore, most of the aforementioned methods directly optimize geometric parameters or local structures, failing to fully utilize the internal flow behavior and energy distribution characteristics of the flow channel to guide the structural configuration. This results in the design process being more of an iterative correction based on result feedback than a direct configuration generation based on flow mechanisms. In multi-outlet fluid distribution problems, such methods struggle to achieve rapid and controllable design for flow uniformity.

[0006] Therefore, it is necessary to propose a new flow channel design method that can quickly achieve uniform distribution of multi-outlet flow based on the inherent laws of flow without large-scale iterative calculations, thereby significantly improving the design efficiency and engineering applicability of fluid distribution systems and overcoming the shortcomings of existing technologies in terms of design speed and determinism.

[0007] In addition, the applicant's prior research proposed a method for extracting flow channel boundaries based on hydrodynamic pressure contour lines. This method directly performs fluid analysis on the initial design domain and extracts hydrodynamic pressure contour lines as flow channel boundaries, which can simplify the design process to a certain extent. However, since the hydrodynamic pressure contour lines are derived from the initial, uncontrolled flow field, the resulting flow channel structure cannot guarantee the uniform distribution of flow rates at each outlet under a uniform outlet pressure condition. Its applicability is limited for situations where the uniformity of flow rates at multiple outlets is required. Summary of the Invention

[0008] The technical problem to be solved:

[0009] To address the issues of high computational cost, long design cycle, and reliance on experience in existing multi-outlet flow distribution channel design methods, as well as the inability of existing dynamic pressure contour-based design methods to directly guarantee flow uniformity, this invention proposes a flow equalization channel design method based on outlet pressure regulation.

[0010] Technical solution:

[0011] This invention guides the flow state within the channel towards uniform distribution by explicitly controlling the outlet pressure boundary conditions. After obtaining a uniform flow distribution state, the channel boundary is directly generated based on the dynamic pressure distribution in this uniform flow field. Unlike existing technologies that directly extract dynamic pressure contour lines from the initial design domain, this invention first achieves a uniform flow distribution state by controlling the outlet pressure, and then extracts dynamic pressure contour lines from this uniform flow field. This ensures that the final channel structure retains excellent flow uniformity even after restoring a unified outlet pressure, achieving rapid, controllable, and uniform distribution of flow from multiple outlets.

[0012] The flow equalization channel design method based on outlet pressure regulation proposed in this invention includes the following steps:

[0013] Step 1: Based on the number of inlets and outlets of the flow channel in the engineering application and their spatial relationship, and combined with the available installation space, establish the geometric model of the design domain of the flow distribution channel; discretize the design domain into several finite element or finite volume calculation units, and set the flow boundary conditions and fluid material parameters; all outlet boundaries are set as pressure outlets, and the initial pressure value is set to the same reference pressure value; the inlet boundaries are set as velocity inlets or mass flow rate inlets; under the above conditions, perform the first numerical analysis of the design domain to obtain the initial flow field distribution inside the flow channel;

[0014] Step 2: Based on the initial flow field analysis results obtained in Step 1, extract the volumetric flow rate or mass flow rate values ​​corresponding to each outlet. ,in This represents different flow channel outlets; simultaneously, the average static pressure at the flow channel inlet is calculated, and combined with the outlet pressure boundary condition, the inlet and outlet pressure drops of the flow distribution channel are obtained. ;

[0015] Step 3: Based on the fluid flow law, calculate the outlet flow rates obtained in Step 2. and import / export pressure reduction Substitute into the following formula and perform algebraic operations to explicitly determine the target outlet pressure boundary value required to achieve a uniform distribution of flow rates at each outlet:

[0016]

[0017] in For the updated version The pressure boundary value of each export. It is a reduction in import and export pressure. and It is the first and the The flow rate of each outlet, The total number of outlets; the average static pressure at the inlet is set as the pressure reference zero point, so the pressure value of each outlet is a relative pressure value relative to this reference zero point;

[0018] The fluid flow law is as follows: Under the premise of keeping the channel geometry and inlet boundary conditions unchanged, the pressure boundary value of each outlet has a monotonically negative correlation with its corresponding outlet flow rate; that is, within a certain range, reducing the pressure boundary value of a certain outlet can increase the flow rate at that outlet. This formula establishes a "negative feedback" mechanism for flow rate... Less than maximum flow The calculated export pressure of the export. A negative value (relative value) means that the pressure at that outlet needs to be reduced. According to the laws of fluid flow, reducing the outlet pressure will increase the flow rate at that outlet, thus causing the flow rates at all outlets to converge towards their maximum values.

[0019] Step 4: Apply the target outlet pressure boundary value calculated in Step 3 to the flow distribution channel design domain model established in Step 1, update the outlet pressure boundary conditions, and perform a second numerical analysis under the updated boundary conditions to obtain the corresponding flow field distribution inside the channel; the flow field obtained at this time is a uniform flow field in which the flow rates at each outlet tend to be evenly distributed.

[0020] Step 5: Based on the velocity field obtained in Step 4 under the uniform flow distribution state, calculate the fluid dynamic pressure using the following formula:

[0021]

[0022] Calculate the dynamic pressure distribution field, where For dynamic pressure, For fluid density, The local velocity magnitude is determined by the dynamic pressure distribution field. Based on this dynamic pressure distribution field, dynamic pressure contour lines or isosurfaces that satisfy the target volume or structural constraints are extracted. These contour lines or isosurfaces are then used as the flow channel boundaries to obtain the corresponding uniform flow channel structure.

[0023] In a further preferred embodiment, the formula in step 3 is derived as follows: the flow distribution channel is equivalent to a constant flow resistance network. Under the condition of ignoring the nonlinear term of local resistance, the flow rate of each branch is linearly related to the pressure difference at both ends of the branch. Taking the maximum flow outlet as the benchmark, the flow rate of other outlets is adjusted to approach the maximum value by adjusting the pressure of other outlets, and the formula is obtained by algebraic transformation.

[0024] In a further preferred embodiment, the extraction range of the dynamic pressure contour lines in step 5 is determined based on the required volume of the target flow channel, structural constraints, or engineering application requirements.

[0025] In a further preferred embodiment, the fluid material parameters in step 1 include density and dynamic viscosity coefficient; the discretization employs a structured or unstructured mesh.

[0026] In a further preferred embodiment, after calculating the dynamic pressure distribution field in step 5, the method further includes: adjusting the values ​​of the dynamic pressure contour lines according to the volume constraints of the flow channel design space, so that the volume of the region enclosed by the contour lines meets the preset requirements; when a smaller flow channel structure is required, a dynamic pressure contour line with a higher value can be selected as the flow channel boundary; conversely, a flow channel structure with a lower value can be obtained by selecting a dynamic pressure contour line with a lower value.

[0027] In a further preferred embodiment, the average static pressure at the inlet is set as a pressure reference zero point, and the pressure values ​​at each outlet are relative pressure values ​​relative to this reference zero point.

[0028] A further preferred embodiment is the pressure drop at the inlet and outlet in step 2. This is the difference between the average static pressure at the inlet and the average static pressure at the outlet of the flow channel.

[0029] In a further preferred embodiment, the geometric model of the design domain established in step 1 is a one-in-multiple-out structure, and the outlets are arranged symmetrically or asymmetrically in spatial position.

[0030] Beneficial effects

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] 1. This invention establishes a clear control relationship between the outlet pressure boundary and the outlet flow rate, and uses the pressure boundary to directly guide the internal flow state of the flow channel to evolve towards uniform distribution. This eliminates the need for multiple rounds of parametric modification of the flow channel geometry or global topology iteration, significantly reducing computational costs and shortening the design cycle.

[0033] 2. After obtaining a uniform flow distribution state, this invention directly extracts the flow channel boundary based on flow physical characteristics such as dynamic pressure distribution, realizing the generation of structural configuration from flow physical characteristics. This avoids the traditional structural design method that relies on experience or trial and error, and the resulting flow channel structure has clear physical meaning and interpretability.

[0034] 3. The method of this invention achieves uniform flow distribution by directly controlling the outlet pressure boundary. Its design process does not rely on multiple rounds of iterative optimization or parameter search. Only a limited number of flow field numerical analyses are needed to complete the design of the flow equalization channel, thereby significantly improving design efficiency and reducing the dependence on the optimization experience and professional background of designers. It has good engineering applicability and promotion value.

[0035] 4. This invention does not depend on specific initial channel geometry, number of outlets, or spatial layout. It is universally applicable to single-inlet-multiple-outlet, asymmetrical, and spatially curved channels. It can be easily integrated into existing commercial CFD software and is readily applicable in aerospace, new energy vehicles, and precision chemical industries.

[0036] 5. Compared with existing design methods based on dynamic pressure contour lines, this invention introduces an outlet pressure regulation step before dynamic pressure extraction, so that the final flow channel structure can still maintain a highly uniform flow distribution under the same outlet pressure conditions.

[0037] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0038] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0039] Figure 1 This is a schematic diagram of a flow channel structure with one inlet and two outlets, as shown in Example 1.

[0040] Figure 2 This is a schematic diagram of the geometric model and mesh division of the one-inlet, two-outlet flow distribution channel design domain, as shown in Example 1.

[0041] Figure 3 This is a velocity field distribution diagram of a one-inlet, two-outlet flow distribution channel under the initial isobaric outlet conditions shown in Example 1.

[0042] Figure 4 The flow channel extraction and reconstruction model based on dynamic pressure distribution is shown in Example 1;

[0043] Figure 5 The velocity cloud diagram of the one-inlet, two-outlet equal flow channel based on outlet pressure regulation design shown in Example 1;

[0044] Figure 6 This is a schematic diagram of the one-inlet, three-outlet flow distribution channel structure shown in Example 2;

[0045] Figure 7 This is a schematic diagram of the geometric model and mesh division of the one-inlet, three-outlet flow distribution channel design domain, as shown in Example 2.

[0046] Figure 8 This is a velocity field cloud diagram of a one-inlet, three-outlet flow distribution channel under the initial isobaric outlet conditions shown in Example 2.

[0047] Figure 9 The flow channel extraction and reconstruction model based on dynamic pressure distribution is shown in Example 2;

[0048] Figure 10 The velocity cloud diagram is shown in Example 2, which is a one-inlet, three-outlet equal flow channel designed based on outlet pressure regulation. Detailed Implementation

[0049] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0050] Example 1: Flow distribution channel with one inlet and two outlets:

[0051] This embodiment uses the cooling channel in an aerospace thermal management system as an engineering application background to specifically illustrate the flow equalization channel design method based on outlet pressure regulation described in this invention.

[0052] In this embodiment, the cooling fluid enters the flow channel system through a single inlet, is distributed through the internal flow channels, and then exits from two outlets to cool two side-by-side heated components. Due to limitations in installation space and structural layout, the two outlets are asymmetrically distributed in space. If conventional isobaric outlet boundary conditions are used, it can easily lead to uneven flow distribution between the two outlets, thereby affecting the overall cooling performance of the system.

[0053] In this embodiment, the design process of the flow equalization channel is strictly carried out in accordance with the outlet pressure control and dynamic pressure feature extraction process proposed in this invention. No parametric modification or structural iteration of the channel geometry is performed during the design process, nor is a multi-round optimization calculation or parameter search method based on the objective function adopted.

[0054] The schematic diagram of the one-inlet, two-outlet flow equalization channel structure used in this embodiment is shown below. Figure 1 As shown.

[0055] The specific implementation steps are as follows:

[0056] Step 1: Based on the actual structural boundaries of the engineering project, establish, within the given feasible space, as follows: Figure 2 (a) shows the initial design domain of a two-dimensional flow distribution channel with one inlet and two outlets. The design domain includes: a velocity inlet located on the upper left side with a width of 5 mm; two pressure outlets asymmetrically arranged on the upper right side, each with a diameter of 5 mm; and a rectangular design envelope space surrounding the inlet and outlet areas, with dimensions of 50 mm × 50 mm. The flow distribution channel design domain is discretized using a structured quadrilateral mesh with a maximum cell size of 0.2 mm, generating a total of 64,375 computational mesh cells. The meshing result is shown below. Figure 2 As shown in (b). Simultaneously, flow boundary conditions and fluid material parameters are set: the inlet boundary is set as a velocity inlet, with a given uniform inflow velocity of 0.01 m / s; both outlet boundaries are set as pressure outlets, with an initial pressure value of 0 Pa (gauge pressure); all other boundaries are set as no-slip walls. Water is selected as the fluid medium, with a density set to... Dynamic viscosity is set to Therefore, a numerical analysis model of a flow distribution channel with one inlet and two outlets is established.

[0057] Step 2: Based on the numerical analysis model established in Step 1, perform the first flow field numerical analysis on the one-inlet, two-outlet flow distribution channel to obtain the initial flow field distribution inside the channel. The velocity field results are as follows: Figure 3 As shown. Based on the initial flow field analysis results, the average pressure value at the inlet was extracted, and combined with the outlet pressure boundary condition, the inlet and outlet pressure drop of the flow channel was calculated to be 0.10465 Pa. Simultaneously, the flow rates corresponding to the two outlets were extracted, with the flow rate at outlet 1 being 0.0268345 kg / s and the flow rate at outlet 2 being 0.023239 kg / s.

[0058] To quantitatively evaluate the uniformity of flow distribution, the root mean square uniformity of flow is introduced as an evaluation index, and its calculation formula is as follows:

[0059]

[0060] in, For the root mean square uniformity of the flow rate, The closer the value is to 1, the more even the flow distribution. For the first The flow rate of each outlet, This is the average of all outbound flows. The output quantity is given. Based on the uniformity formula, the root mean square uniformity of the flow rate in this initial flow distribution channel is calculated to be 0.9282.

[0061] Step 3: Based on the two outlet flow rates and inlet / outlet pressure drops obtained in Step 2 Based on the control relationship between the outlet pressure boundary and the outlet flow rate established by this invention, and substituted into the formula...

[0062]

[0063] calculate:

[0064]

[0065]

[0066]

[0067]

[0068] Calculation results show that the target pressure boundary values ​​corresponding to outlet 1 and outlet 2 are respectively and In this process, the target outlet pressure boundary value is obtained directly through analytical calculation, without the need for multiple sets of pressure parameters to be tried or stepwise approximation calculations.

[0069] The formulas in this step are derived based on a constant flow resistance network model. Ignoring local nonlinear resistance, the multi-outlet flow channel is equivalent to a linear flow network consisting of the inlet and each outlet branch, where the flow rate of each branch is proportional to the pressure difference across that branch. Using the initial isobaric outlet distribution as a benchmark, to achieve uniform flow distribution across all outlets, additional negative pressure is applied to outlets with flow rates below their maximum value. This negative pressure is positively correlated with the flow deficit at that outlet (i.e., the difference between the maximum flow rate and the current flow rate). Dimensional analysis yields the explicit control formula:

[0070]

[0071] The physical meaning of this formula is: after normalizing the total pressure drop to the total flow rate, multiplying it by the flow deficit of each outlet yields the pressure correction value required to bring the flow rate of that outlet closer to its maximum value.

[0072] Step 4: Based on the target outlet pressure boundary value obtained in Step 3, update the outlet pressure boundary conditions in the flow distribution channel design domain model established in Step 1, and set the outlet pressure to be... Set the outlet pressure to 2 A second numerical analysis of the flow field was performed on the channel under the updated boundary conditions. The flow rates at outlet 1 and outlet 2 were extracted at this time. and At this point, the outflow uniformity of the flow distribution channel is 0.999. The analysis results show that, under the control of the outlet pressure, the flow distribution at the two outlets significantly tends to be consistent, achieving a uniform flow state in the one-inlet, two-outlet flow distribution channel.

[0073] Step 5: Based on the velocity field obtained in Step 4 under the condition of uniform flow distribution, calculate the fluid dynamic pressure using the following formula:

[0074] The corresponding dynamic pressure distribution field is calculated. Based on the dynamic pressure distribution field, and according to the required volume and structural constraints of the target flow channel, the corresponding dynamic pressure contour lines are extracted. The dynamic pressure distribution field and the extracted dynamic pressure contour lines are shown below. Figure 4 As shown in (a), and using the dynamic pressure contour lines as the flow channel boundary, the uniform flow channel structure is reconstructed, and the reconstructed uniform flow channel structure is as follows. Figure 4 As shown in (b).

[0075] Performance verification of a one-in-two-out flow distribution channel:

[0076] To verify the flow distribution performance of the flow equalization channel structure obtained based on outlet pressure regulation and dynamic pressure feature extraction under actual working conditions, the performance verification analysis of the flow equalization channel structure reconstructed in step 5 is performed.

[0077] While keeping the inlet boundary conditions, fluid medium parameters, and overall structural dimensions unchanged, a numerical analysis model of the uniform flow channel structure was re-established, and the two outlet boundary conditions were uniformly set to pressure outlet boundaries with a gauge pressure of 0 Pa to simulate the actual operating conditions of the project.

[0078] Numerical analysis was performed on the uniform flow channel structure under the above boundary conditions, and the flow field distribution results are as follows: Figure 5 As shown. Based on the analysis results, the flow rates corresponding to the two outlets were extracted, with the flow rate at outlet 1 being 0.025118 kg / s and the flow rate at outlet 2 being 0.0249595 kg / s. The root mean square uniformity of the flow rate of this uniform flow channel structure was calculated to be 0.99683 using the uniformity formula.

[0079] Compared to the initial design domain model, the root mean square uniformity of the flow rate is improved by approximately 7.39%, indicating that the flow uniform channel structure obtained by the method of this invention can still achieve stable and uniform distribution of the flow rate at each outlet without the need for additional outlet pressure control. This verifies the effectiveness and engineering applicability of the method of this invention in multi-outlet flow rate distribution problems.

[0080] Furthermore, from the perspective of iteration efficiency, the formation process of the one-inlet, two-outlet flow-equalizing channel in this embodiment only includes one flow field numerical analysis under the initial isobaric outlet condition and one flow field numerical analysis based on the updated target outlet pressure boundary, totaling two core flow field solutions. In contrast, conventional parameter optimization or sample point evaluation methods require repeated analysis of a large number of parameter combinations. Compared with the common 160-sample evaluation optimization process of traditional methods, the number of evaluations in this invention can be reduced by approximately 98.75%. From the perspective of time efficiency, if the time taken for a single two-dimensional steady-state CFD numerical analysis on a typical engineering workstation is approximately 5-10 seconds, then the time required to complete the core flow-equalizing design in this embodiment is approximately 10-20 seconds; while under the same single solution time condition, the equivalent total computation time for the 160-sample evaluation process is approximately 13-27 minutes. Therefore, this invention has a significant time efficiency advantage while ensuring flow-equalizing performance. This time is an equivalent estimate under the same single solution time condition and is only used to illustrate the engineering time efficiency advantage of this invention compared to multi-round optimization processes.

[0081] In summary, this embodiment demonstrates that the method of the present invention, in the problem of asymmetric flow distribution with one inlet and two outlets, not only has the characteristics of being non-iterative, computationally efficient, and easy to implement in engineering, but also maintains a high level of uniform flow distribution performance after restoring the actual operating conditions to a uniform isobaric outlet.

[0082] Example 2: Flow distribution channel with one inlet and three outlets - flow equalization design

[0083] This embodiment uses the cooling channel in the thermal management system of a new energy battery as an engineering application background to specifically illustrate the flow equalization channel design method based on outlet pressure regulation described in this invention.

[0084] In this embodiment, the cooling fluid enters the flow channel system through a single inlet, is distributed through the internal flow channels, and then exits from three outlets to cool three spatially asymmetrically arranged heated components. Due to the differences in the spatial location of the outlets and the uneven distribution of resistance within the flow channels, there are significant differences in the flow rates at each outlet under the initial isobaric outlet boundary conditions, thus affecting the overall cooling performance of the system.

[0085] The schematic diagram of the one-inlet, three-outlet flow distribution channel structure used in this embodiment is as follows: Figure 6 As shown.

[0086] The specific implementation steps are as follows:

[0087] Step 1: Within the given feasible installation space, establish an initial design domain model of a one-inlet, three-outlet two-dimensional flow distribution channel, with its geometry and dimensions as follows: Figure 7As shown in (a), the inlet boundary conditions and fluid properties are uniformly set. The inlet adopts a velocity inlet boundary with a velocity of 0.01 m / s, and all three outlets adopt pressure outlet boundaries with a pressure set to 0 Pa. Based on this, a numerical analysis model of a one-inlet, three-outlet flow distribution channel is constructed.

[0088] Step 2: Based on the numerical analysis model established in Step 1, conduct the first flow field numerical analysis on the one-inlet, three-outlet flow distribution channel to obtain the initial flow field distribution inside the channel, and its velocity distribution cloud map is shown below. Figure 8 As shown. Based on the initial flow field analysis results, the average pressure value of the inlet section was extracted, and combined with the outlet pressure boundary condition, the inlet and outlet pressure drop of the flow channel was calculated to be 0.0893 Pa. Simultaneously, the flow rates corresponding to the three outlets were extracted: outlet 1 had a flow rate of 0.0200 kg / s, outlet 2 had a flow rate of 0.0142 kg / s, and outlet 3 had a flow rate of 0.0162 kg / s.

[0089] Step 3: Based on the three outlet flow rates and inlet / outlet pressure drops obtained in Step 2 Based on the control relationship between the outlet pressure boundary and the outlet flow rate established by this invention, and substituted into the formula...

[0090]

[0091] Perform the calculation:

[0092]

[0093]

[0094]

[0095]

[0096]

[0097] Calculation results show that the target pressure boundary values ​​corresponding to outlet 1, outlet 2, and outlet 3 are respectively , and In this process, the target outlet pressure boundary value is obtained directly through analytical calculation, without the need for trial calculations of multiple sets of pressure parameters or stepwise approximation calculations.

[0098] Step 4: Based on the target outlet pressure boundary value determined in Step 3, update the outlet pressure boundary conditions of the flow distribution channel design domain model established in Step 1, and conduct a second flow field numerical analysis of the channel under the updated boundary conditions. The results show that the flow rates at outlets 1, 2, and 3 are 0.0166 kg / s, 0.0172 kg / s, and 0.0166 kg / s, respectively, with a corresponding flow distribution uniformity of 0.979. The analysis results show that under the effect of outlet pressure regulation, the flow distribution at the three outlets significantly tends to be consistent, achieving a uniform flow state in the one-inlet, three-outlet flow distribution channel.

[0099] Step 5: Based on the velocity field obtained in Step 4 under the condition of uniform flow distribution, calculate the corresponding dynamic pressure distribution field according to the fluid dynamic pressure calculation formula. Based on this dynamic pressure distribution field, and considering the volume and structural constraints required by the target flow channel, extract the corresponding dynamic pressure contour lines. The dynamic pressure distribution field and the extracted dynamic pressure contour lines are shown below. Figure 9 As shown in (a), and using the dynamic pressure contour lines as the flow channel boundary, the flow equalization channel structure is reconstructed to obtain a one-inlet, three-outlet flow distribution channel with uniform outlet flow. The reconstructed flow equalization channel structure is as follows: Figure 9 As shown in (b).

[0100] Performance verification of a one-in-three-out flow distribution channel:

[0101] To verify the flow distribution performance of the flow equalization channel structure obtained based on the outlet pressure regulation and dynamic pressure feature extraction method under actual working conditions, a performance verification analysis was conducted on the flow equalization channel structure reconstructed in step 5.

[0102] While keeping the inlet boundary conditions, fluid medium parameters, and overall structural dimensions unchanged, a numerical analysis model of the uniform flow channel structure was re-established, and the three outlet boundary conditions were uniformly set to 0Pa pressure outlets to simulate the actual operating conditions of the project.

[0103] Compared with the initial design domain model, its root mean square uniformity of flow is improved by about 9.08%, indicating that the flow uniform channel structure obtained by the method of the present invention can still achieve stable and uniform distribution of flow at each outlet without the need for additional outlet pressure control, thus verifying the effectiveness and engineering applicability of the method of the present invention in multi-outlet flow distribution problems.

[0104] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A flow equalization channel design method based on outlet pressure regulation, characterized in that: Includes the following steps: Step 1: Establish the geometric model of the design domain of the flow distribution channel and discretize it. Set the flow boundary conditions and fluid material parameters. All outlet boundaries are set as pressure outlets with the same initial pressure value, and the inlet boundaries are set as velocity inlets or mass flow rate inlets. Perform the first numerical analysis on the design domain to obtain the initial flow field distribution. Step 2: Based on the initial flow field analysis results, extract the flow rate values ​​of each outlet. and the pressure drop at the inlet and outlet of the flow channel. ,in Indicates different flow channel outlets; Step 3: Calculate the outflow rates obtained in Step 2. and import / export pressure reduction Substitute into the following formula to calculate the target outlet pressure boundary value required to make the flow rates at each outlet tend to be uniformly distributed: in For the updated version The pressure boundary value of each export, Total exports; Step 4: Apply the target outlet pressure boundary value calculated in Step 3 to the model established in Step 1, update the outlet pressure boundary conditions, and perform a second numerical analysis to obtain a uniform flow field in which the flow rates at each outlet tend to be evenly distributed. Step 5: Based on the velocity field in the uniform flow field obtained in Step 4, calculate the dynamic pressure distribution field, and extract the dynamic pressure contour lines or isosurfaces based on the dynamic pressure distribution field. Use the dynamic pressure contour lines or isosurfaces as the flow channel boundary to obtain the uniform flow channel structure.

2. The flow equalization channel design method based on outlet pressure regulation according to claim 1, characterized in that, The formula in step 3 is derived based on the following physical model: the flow distribution channel is equivalent to a constant flow resistance network. Under the condition of ignoring the nonlinear term of local resistance, the flow rate of each branch is linearly related to the pressure difference at both ends of the branch. Taking the maximum flow outlet as the benchmark, the flow rate of other outlets is adjusted to approach the maximum value by adjusting the pressure of other outlets, and the formula is obtained by algebraic transformation.

3. The flow equalization channel design method based on outlet pressure regulation according to claim 1, characterized in that, In step 5, the extraction range of the dynamic pressure contour lines is determined based on the volume constraints and / or structural constraints required by the target flow channel.

4. The flow equalization channel design method based on outlet pressure regulation according to claim 1, characterized in that, The fluid material parameters in step 1 include density and dynamic viscosity coefficient; the discretization uses a structured mesh or an unstructured mesh.

5. The flow equalization channel design method based on outlet pressure regulation according to claim 1, characterized in that, After calculating the dynamic pressure distribution field in step 5, the method further includes: adjusting the values ​​of the extracted dynamic pressure contour lines according to the volume constraints of the flow channel design space, so that the volume of the region enclosed by the contour lines meets the preset requirements.

6. The flow equalization channel design method based on outlet pressure regulation according to claim 1, characterized in that, The average static pressure at the inlet is set as the pressure reference zero point, and the pressure values ​​at each outlet are relative to this reference zero point.

7. The flow equalization channel design method based on outlet pressure regulation according to claim 1, characterized in that, Inlet and outlet pressure drop in step 2 This is the difference between the average static pressure at the inlet and the average static pressure at the outlet of the flow channel.

8. The flow equalization channel design method based on outlet pressure regulation according to claim 1, characterized in that, The geometric model of the design domain established in step 1 is a one-in-multiple-out structure, and the outlets are arranged symmetrically or asymmetrically in space.

9. The flow equalization channel design method based on outlet pressure regulation according to claim 1, characterized in that, The dynamic pressure distribution field in step 5 is based on the formula Calculation, where For dynamic pressure, For fluid density, This represents the local velocity magnitude.

10. The flow equalization channel design method based on outlet pressure regulation according to any one of claims 1 to 9, characterized in that, The method requires only two numerical analyses to obtain a flow channel structure with uniform flow distribution performance under a uniform outlet pressure.

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