Numerical simulation of viscous free surface flow

Methods used to track the free surface in numerical flow simulations, typically during the casting of metals into moulds are examined in this paper. The algorithm employed makes use of a mixed interpolation formulation to approximate the discretised governing equations for elimination on a Langrangian type moving mesh. Significant savings in CPU time are realised by virtue of the the air domain not being considered in the finite element analysis. The advantages and drawbacks of commonly used methods are discussed, and a method proposed for the numerical simulation of flow where the free surface boundary conditions are important. The effectiveness of the proposed algorithm in solving typical industrial flow problems is demonstrated using numerical examples. The results obtained are compared with analytical and numerical data with a view to validating the algorithm.