Physical-geometrical Coupling Rule And Design Of Fluid Field Of Aluminum Melt Of Continuous Roll Casting

Shaped nozzle cavity is main element to form the fluid and thermal field. Good fluid and thermal field are necessary to produce high quality the aluminium roll casting strip and to improve production efficiency. This issue derivates the best form of fluid and thermal field: the flow speed at outlet of nozzle distributing along the latitude direction of roll casting strip should be almost the same; the temperature of the two sides and the middle of outlet should differ between the two limits of, and temperature of the middle should be a little lower than that of either side.According to data of reality experiments, the fluid fields of the front-box and the nozzle cavity of aluminum roll-casting are performed by using coupled fluid-thermal FEM simulation of the FLOTRAN module of the general finite element analysis software, ANSYS. Based on the post-processing function of ANSYS and MATLAB, the advanced result analysis was conducted. The mid-plane, outlet plane and midline of outlet are chosen to be the emphases of analysis.This study infers quantified design reference standard for fluid field and thermal field by analyzing the nozzle models of single and double spacers conducted in two on-the-site experiments and data accumulated in past experiments, and further initially claimed that the "tv" value which is resulted from velocity multiple temperature as a new evaluation indicator for the coupled fluid-thermal analysis evaluation system. These indicators have also been used in all models in this study.By analyzing nozzles without spacer, we can make sure the effect degree of the geometrical factors constructing the nozzle cavity are: under the same size of front-box and the level of liquid, aperture width of nozzle outlet has the most effect to fluid and thermal field of model, and length of outlet (along the latitude direction) and aperture width of nozzle entrance are the second and third respectively.Experiments were conducted using four ordinary kinds of nozzle cavity, such as water-drop-spacer shape, 3C shape, crescent-spacer shape and nine-spacer shape respectively, calculating under three drawing-sheet speeds varied from the low to high. The uneven distribution exists in regular status outstands in higher speed. So it is recommended a stricter requirement to the design of temperature and velocity of fluid field.The analysis of furthur optimization design of the nozzle cavity of 3C shape indicated that an improved result would be attained by using middle spacer with it's tip getting farther from outlet, and good match of geometric parameter of spacers.