High Temperature Melt Aluminum Alloy Casting Casting Tip Dimensional Flow Field And Temperature Field Numerical Simulation Study

Different from other continuous casting process, Twin-roll continuous casting is a kind of synthetical technique that integrates solidification and deformation. One of the key techniques in twin-roll casting is the nozzle's structure. The nozzle directly distributes the melted aluminum into the twin-roll gap. The distribution of the melted aluminum's fluid field and temperature field in the nozzle signifcantly influence the quality of the casting aluminium sheets or strips. Especially, the uniformness of the melted aluminum's velocity and temperature distribution at the cavity exit decides whether the twin-roll casting process can be successfully accomplished and thus high quality casting strips can be obtained. So it is very important to research the rules of the high temperature flimsy melted aluminum's fluid field and temperature field in three dimensions and analyze the relationship between some parameters and the uniformness of the melted aluminum's velocity and temperature distribution at cavity exit in the nozzle with big wideth-thickness ratio and veriating transverse section.Based on the particular characteristics of the nozzle, the special properties of the melted aluminum and the flexiblity of the surroundings, this paper models the high temperature flimsy metled aluminum in three dimensions and analyzes the distribution rules of fluid field and temperature field at the cavity exit by using the ANSYS software.The focus is as the following:1. The three-dimensional mathmatical and physical model of the fluid field and temperature field is established about the high temperature flimsy melted aluminum in the twin-roll casting nozzle.2. With the FEM analysis software ANSYS, the three-dimension element and corresponding DOF solver are correctly selected. Especially, the problem about the process of the boundary condition and loading are solved during the simulating course.3. The three-dimensional fluid field and temperature field of the steady high temperature melted aluminum with variable fluidproperty(the variable density) is numerically simulated. The affect of some parameters to the melted aluminum, such as two-roll casting speed, numbers of divergent fluid block, thickness of the two-roll nozzle exit and cavity length are systemically analyzed. Moreover, numerical simulation of the constant- density and variable density melted aluminum is simply compared. The numerical simulation had shown : The distribution rule of the high temperature flimsy melted aluminum's three-dimension fluid field and temperature field is revealed and the conclusions are drawn that three-dimension model should be established and two-dimension model is irrational and impractical, that melt flow direction speed and exit temperature increase with the increasing of casting speed, that it can improve uniform of tip cavity exit distribution velocity and temperature to change cavity entrance distribution velocity and numbers of divergent fluid block , properly reduce thickness of the two-roll nozzle exit and extend cavity length and that it is rational to take the variable density as the constant density in practical project. So the best matching parameters is provided for the two-roll casting, especially for the fast-solidification two-roll casting by the numerical simulation .4. Datum of the water simulating of melt flow is presented and the surface temperature of nozzle is tested during the roll-casting fieldwork. The related data are collected. The water simulating experiment shows that the simulation result is well consisted with the experimental data, temperature experiment provides referenced base for temperature boundary condition of numerical simulation .Thereby, the model and conclusion is right.