Effect of porosity on exhaust performance of tire block pattern mould

The gas in the closed cavity of the tire mold is mainly discharged through the air hole, and the design factor directly affects the exhaust performance of the mold. Based on the theory of fluid dynamics, this paper constructs the three-dimensional structure of block pattern, and uses numerical simulation software to study the variation law of physical flow such as fluid flow trajectory, exhaust time and average exit velocity, and analyzes the influence of the type and quantity of vent on the exhaust performance of the block pattern. The results show that the vortex is easy to be generated inside the block-shaped cavity. The air hole of model 2 mm is greatly affected by it, and the exit speed fluctuates up and down. The number of air holes is 3. When the model is 2 mm, it needs 0.40 s to discharge the air inside the cavity. The 3 mm pores only need 0.36 s, and the time is shortened by 10%. When the size of the pattern is fixed, the number and type of the pores are reasonably selected to uniformly discharge the gas, which can reduce the influence of the vortex on the exhaust performance, shorten the exhaust time, and obtain better exhaust performance.