The Analysis Of Fluid Flow Characteristics And The Forming Process Research About Rectangular Section Curved Pipe

As one of the efficient and cheap system, pipeline transport occupies the important position in the process of production and construction and it is widely used in electric power, metallurgy, chemical industry, construction, oil and other industries. With the advantages of light quality, good strength, rectangular section curved pipe usually is used as conveying fluid. At the same time of guaranteeing the strength, it can greatly save material and it has a very broad application prospects in the field of automotive industry. There are two forms of the bending of rectangular tube structure; one is along the width of the rectangular pipe surface in the form of bending, it is called E bending. Another one is in the form of narrow surface of rectangular pipe bending, it is called H bending. In the practical engineering, under the action of fluid medium the curved pipe is vulnerable to uneven pressure load to come into being the phenomenon of stress concentration.The article which is based on under the action of fluid medium the curved pipe is vulnerable to uneven pressure and the quality defects produced during bend forming process, carries out related research. It is mainly studied about the fluid flow situation of rectangular pipe through Fluent and a finite element model of rectangular section tube is built by ABAQUS to get the stress and strain in different bending process. The distribution rules of fluid pressure loads on wall surface of curved pipe have been analyzed, the mathematical model which described the pressure in convex side and concave side is also given. And the process parameters which affect the forming quality of the bending pipe are analyzed. The research result is of great significance to accurately analyze the wall pressure in curved pipe under the effect of fluid and to select the process parameters during the bending forming process. The following work to this article is:1. Three different kinds of rectangular section curved pipes, which are in the same area of section including the E bending pipe, H bending pipe and the square pipe are established by UG, which are studied about the wall of pressure value and the fluid flow condition by the fluid simulation computation software Fluent. Then it makes a conclusion that the E bending is the optimal condition under the effect of pressure.2. The distribution rules of fluid pressure loads on wall surface of curved pipe have been analyzed under the typical operating condition by Fluent. By changing the parameters (fluid velocity, fluid outlet pressure, elbow pipe bending percentage, fluid density, etc) of influencing the pressure of internal face, this paper analyzes the influence law of internal wall pressure under various parameters. Furthermore, the pressure formula including the parameters (fluid velocity v, fluid outlet pressure Po, elbow pipe bending percentage k, the axial angle of elbow pipe a and fluid density ρ)about the pressure in convex side and concave side of rectangular section curved pipe is fitted out by the fitting software lstOpt.3. Based on the finite element analysis software ABAQUS, the finite element model of rectangular section tube is built to get the stress and strain in different bending process through analog simulation. The parameters which affect the forming quality of the bending pipe are deeply analyzed. It is of important significance for improving the processing and forming technology, explaining the forming defect in the production, control pipe bending forming quality.