Virtual reality technology has been widely used in engineering structure design and manu2facture due to its high efficiency and obvious characteristics which are different from traditional way.The paper gave a detailed introduction of its application in valve design. A virtual experiment was con2ducted to calculate the extreme stress in order to optimize the valve structure. Stress concentration ofopenings on valve is discussed and the relationship between sealing face and seal pressure is establishedby employing effective seal pressure. The simulation results show that the virtual reality technologycan provide a quantitative evaluation for valve strength and seal properties , which is necessary forvalve design both theoretically and practically.
Simulation test steps The valve product has a high degree of structural similarity and is suitable for using modules Normalization and parameterization design have the same or similar design calculation modes Like. In addition, there are many standard and universal parts for valves, which facilitates the application of group technology and feature modeling technology in CAD systems. In valve installation During the development process, virtual design and simulation experiments are used to conduct valve testing Door optimization can not only obtain high-quality products, but also reduce costs. For valve testing, the strength of the valve body and the sealing of the sealing surface Performance is within the main scope of testing. Stress and sealing on the valve body The distribution of pressure on the sealing surface is used in practical design Testing or correcting formulas, although this method has a high safety factor, is difficult To meet the requirements of valve design development. Using practical means, these two The parameters are difficult to accurately measure. By conducting simulation experiments, designers can To obtain precise separation of stress and sealing ratio pressure on the valve body and sealing surface The distribution of results makes the design and improvement of valves more targeted and accurate Accuracy. Valve simulation belongs to static structural analysis, and its testing steps are as follows As shown in Figure 1. During the valve simulation test, it is necessary to establish a valve Door solid model, finite element model mesh division, defining boundary conditions The work of analyzing and calculating results
(1) establishes a solid model of the valve from the purpose of analysis Establish a model and make necessary changes to the model structure, such as analyzing The target is the flow characteristics when the valve is fully open and the fluid inside the flow channel The velocity distribution is irrelevant to the characteristics of the valve outer wall and the analysis target It can be completely omitted or simplified.
(2) The quality of mesh division in finite element models affects the calculation time The spacing and accuracy are greatly affected. Generally, before ensuring the quality of grid generation The finer the grid, the higher the computational accuracy, but the required calculations The longer the time. The analysis of the contact relationship between valve components requires multiple iterations Proxy solving consumes a lot of computation time and resources. For large Calculate the sealing pressure ratio of the sealing surface of the caliber butterfly valve, and compare it with the diameter size, The width of the sealing surface is relatively small, as it is the focus of analysis, Therefore, the grid at this location should be appropriately refined for other positions of the valve Placing a grid can reduce distribution density and save computation time.
(3) The definition of boundary conditions and virtual operating conditions is mainly based on the actual operating conditions of the valve, which constrains and loads its model. For valves with simple structures, the plane formed by the operating axis and the centerline of the flow channel can serve as the symmetry plane of the valve structure. Applying constraints on the valve body section at this position can make the results more accurate. When considering the stress caused by temperature difference on the valve body, the displacement constraint applied on the symmetrical section can completely eliminate the stress concentration caused by the constraint. Without affecting the analysis results, some components unrelated to the analysis target can be omitted to reduce calculation time, which is particularly effective in situations with large computational loads. For example, when calculating the specific pressure of the sealing surface, equivalent constraints can be applied to the sealing components (valve seat, sealing ring, etc.), and fastening components can be omitted according to the situation.
(4) For the final analysis and calculation results, targeted data extraction and analysis should be carried out. If a hydraulic strength test is conducted on a hard sealed butterfly valve to obtain the stress distribution of the entire valve, the main focus is usually on the stress distribution on the valve body, and only the stress results of the valve body need to be extracted. To observe the sealing effect of the valve, it is necessary to extract the pressure distribution data on the sealing surface.
