A Simulation Method for Fluid Jetting and Structural Optimization in Pressure Storage Vessels Based on Fluent

Abstract

This invention proposes a simulation method for fluid injection and structural optimization in pressure storage vessels based on Fluent, belonging to the field of fluid simulation and pressure storage vessel design technology. By constructing a system simulation behavior model and applying the ant colony algorithm for path planning, it can accurately simulate the dynamic characteristics during the injection process. Furthermore, it uses code generation technology to automatically generate simulation configuration file code to support the execution of simulation simulations. This method aims to help engineers quickly generate optimal path solutions based on system requirements and constraints, improve the efficiency of simulation configuration file construction, and ensure data consistency and seamless integration between design and simulation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fluid simulation and pressure storage container design, particularly to a method for simulating and optimizing the fluid injection process of a pressure storage container based on Fluent software. BACKGROUND

[0002] The existing pressure storage container injection process relies on physical tests to determine the bottle opening size and injection parameters, which is time-consuming and costly. In addition, it is not easy to accurately capture the fluid acceleration characteristics at the bottle opening in the test, affecting the design optimization effect. With the help of computational fluid dynamics (CFD) simulation technology, the injection process can be accurately simulated, improving the efficiency and accuracy of pressure storage container design. SUMMARY

[0003] The present application proposes a pressure storage container fluid injection simulation method based on Fluent software, which can accurately simulate the dynamic characteristics of the injection process and provide an optimized design scheme. This method reduces costs while improving design efficiency, providing reliable technical support for the research and development of pressure storage containers and related injection systems.

[0004] Speed change: As the bottle opening size increases, the injection speed overall shows a downward trend, but the injection volume improves; Injection time: After optimizing the bottle opening size, the total injection volume per unit time increases, and the injection process is more efficient; Optimization result: By adjusting the bottle opening size and initial pressure, efficient injection is achieved, reducing the residual amount of fire extinguishing agent.

[0005] The present application simulates the injection behavior under different injection port sizes and initial pressures by using Fluent software to simulate and analyze the injection process of the pressure storage container, obtains the variation law of injection speed, pressure and mass flow rate, and thus realizes design optimization; This method not only reduces the test cost, but also greatly shortens the development cycle. BRIEF DESCRIPTION OF DRAWINGS

[0006] Figure 1 is a schematic diagram of a three-dimensional model of a pressure storage container;

[0007] Figure 2 is an injection speed cloud map under different bottle opening sizes;

[0008] Figure 3 is a schematic diagram of the flow state of fire extinguishing agent at the end of injection. DETAILED DESCRIPTION

[0009] Step S1: Use a three-dimensional modeling software to create a model of the pressure storage container and its injection structure, including the geometric parameters of the bottle opening;

[0010] Step S2: Extract the fluid flow domain from the three-dimensional model and divide the flow domain using structured and unstructured grid technology;

[0011] Step S4: Solver and parameter setting; set multiphase flow model and turbulence model, open energy equation;

[0012] Step S5: Set high-pressure gas (such as nitrogen) as power source, initial pressure range set to 4.2 MPa, and set liquid extinguishing agent as injection medium;

[0013] Step S6: Select monitoring area monitoring surface, track dynamic changes of injection speed, pressure and temperature, and fluid acceleration phenomenon, and obtain injection speed-time relationship;

[0014] Step S7: Verify whether the injection efficiency meets the requirements, if yes, end the simulation, if not, adjust the three-dimensional model injection port size, return to step S1 and recalculate.

[0015] Step 1: Establish three-dimensional model

[0016] Use SolidWorks software to establish three-dimensional model of pressure storage container and its injection device. According to design requirements, bottle opening diameter is set to multiple sizes (such as 35.5mm, 37mm, 38.5mm, 41.5mm).

[0017] Step 2: Flow domain extraction and meshing

[0018] Extract the fluid region inside the pressure storage container, delete unnecessary chamfers and gaps. Use structured mesh in the bottle opening area, and use unstructured mesh in the remaining irregular area. Set the topological relationship of fluid and solid interface to ensure that the mesh in the fluid-structure coupling area shares nodes.

[0019] Step 3: Set boundary conditions and initial parameters

[0020] Set high-pressure nitrogen as power source, initial pressure as 4.2 MPa. Liquid extinguishing agent as injection medium, total mass as 3kg. Bottle opening out boundary condition set as pressure-outlet.

[0021] Step 4: Injection process simulation

[0022] Load simulation model in Fluent, select pressure coupling solution method (such as SIMPLE algorithm). Use dynamic mesh technology to simulate the change of compressed gas in the bottle during injection process. Track the changes of injection speed, pressure and flow rate at different time steps.

[0023] Step 5: Dynamic mesh and fluid-structure coupling calculation

[0024] Write a User-Defined Function (UDF) to control the movement of the dynamic mesh region. Based on fluid-structure interaction (FSI) technology, realize the dynamic interaction between the fluid and solid in the bottle opening region. Update the fluid flow state at the bottle opening in real time using dynamic mesh technology and obtain velocity and pressure contour maps.

[0025] Step 6: Optimize Design and Analysis

[0026] The spraying performance under different bottle opening sizes was compared; based on the simulation results, the bottle opening size was adjusted to increase the total spray volume and speed.

Claims

1. A simulation method for fluid jetting and structural optimization of pressurized containers based on Fluent, characterized in that: Includes the following steps: Step S1: Use 3D modeling software to create a model of the pressure storage container and its injection structure, including the geometric parameters of the bottle opening; Step S2: Extract the fluid domain from the 3D model and divide the domain using structured and unstructured meshing techniques; Step S4: Set up the multiphase flow model and turbulence model, and enable the energy equation; Step S5: Set high-pressure nitrogen as the power source, set the initial pressure range to 4.2 MPa, and set liquid extinguishing agent as the spray medium; Step S6: Select the monitoring area and monitor the surface to track the dynamic changes in jet velocity, pressure and temperature and fluid acceleration phenomena, and obtain the relationship between jet velocity and time; Step S7: Verify whether the injection efficiency meets the requirements. If it does, end the simulation. If it does not, adjust the size of the injection nozzle in the 3D model and return to step S1 to recalculate.

2. The simulation method for fluid jetting and structural optimization of a pressure storage vessel based on Fluent as described in claim 1, characterized in that: Step S1 specifically involves: The location of the nitrogen-extinguishing agent interface is determined by the volume of the extinguishing agent being filled. When creating the model using 3D modeling software, air, extinguishing agent, and nitrogen regions are created separately in the same model, and the three regions are set not to be merged.

3. The simulation method for fluid jetting and structural optimization of a pressure storage vessel based on Fluent as described in claim 1, characterized in that: Step S2 specifically involves: Based on the 3D model, fluid flow domains are established for the air region, extinguishing agent region, and nitrogen region. The bottle type is set as a wall. Interfaces are set between the air region and the extinguishing agent region, and between the extinguishing agent region and the nitrogen region. Structured mesh technology is used to divide the flow domains, while unstructured mesh technology is used to divide the flow domains near the bottle mouth and bottle body.

4. The simulation method for fluid jetting and structural optimization of a pressure storage vessel based on Fluent as described in claim 1, characterized in that: Step S4 specifically involves: The multiphase flow model uses the volume of fluid method to simulate air, nitrogen, and liquid extinguishing agent, setting air as the main phase, nitrogen and liquid extinguishing agent as the second phase, and the interaction between each phase as a constant.

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