| Through the reasonable simplification of the pin barrel extruder structure , we get the model for numerical simulation and experiment. Under the given boundary condition , we applied the finite element program ANSYS to the analysis of the model and verify it in the experiment. After that we utilized the mixing theory based on the velocity of the area variety, analyze the mixing effect of the model , and discussed the factors that determine the mixing effect . Through the simulation of fluid and the analysis of mixing effect , we bring forward the factors which affect the mixing effect and the methods which estimate the mixing effect , provide a guide and reference for the design and optimization of the Pin Barrel Extruder .In fact, Pin Extruder has existed for a long period. Since the 1920's, it has been applied to the industrial production. With the spread of the application, more and more improvements have been bring forward aiming at the limitation of the Extruder. All these had been utilized widely and successfully in the industrial production, and considerable economic benefit had been made. To the first idea and the last success, there are two important factors. One is the profuse experience and plenty of data during the production; the other is the understanding of the property of the processed material, including the physical and the chemical.But during a long period of time we deal with it depending on the first point to a deep degree. Until now the solution of fluid is still a hard nut to crack. Even under the ideal condition, the equation obtained is still a group of nonlinear differential coefficient equations. Only for some special condition, after simplifying the model we can get the theoretical solution. But for the actual viscous flow, the difficulty is almost out of our imagination. Because of the property of nonlinear which characterizes the equations, to a greatboundary condition. So in theory we can't gain a uniform form of solution recently.With the strengthen of industrial production, the request of theoretical conduct in the industrial production has been required seriously. The study and development of Pin Barrel Extruder mentioned above encounter such problems. We know that such modifications will improve the extruding production , decrease the cost of power, increase the efficiency, but we haven't understood why they are gotten or know a little about them. To the performance after improvement , we usually predict by experience and test through the production. By a serial of iterative practices, we may find a satisfied result. This method is a basic means of study , but there is such a fact that the time and range of experiments are confined by the two aspects of time and economics. So the conduct in theory is very essential and timely.As we mentioned, the solution of the fluid equations has not been gotten perfectly solved until now, so it is impossible to do a completely theoretical analysis at present. But the appearance of the computer and the development of the numerical simulation have made the solution for this problem practicable. In the thesis the finite element program is utilized in a provided boundary condition (providing the problem is constant to time), then the distribution of the velocity is obtained, afterward by the mixing theory we have come up with the mixing effect is gotten. Some results are worked out by the contrast of the difference of the different structures.After the numerical analysis and the disposal of the velocity of the fluid for mixing effect, we find several traits. First, for the non-pin structure system, the distribution of the velocity of flow is relative regular. The distribution of the velocity between spiral channels is similar. In general the variety of velocity behaves in the variety of the value , and the variety in the direction is very little. Second, for pin structure system, the distribution of the velocity ofboundary condition. So in theory we can't gain a uniform form of solution recently.With the strengthen o... |
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