A transport model for dispersed two-phased flows : development and implementation

• Main Author: Elsden, M.
• Other Authors: Hutchinson, P.
• Published: Cranfield University 1995
• Subjects: 620.106
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.514166

Two-phase flows are found in many industrial and natural processes, from the combustion chambers of aero-engines to silt transport in rivers. The interaction between the two, or more, phases is extremely complex and is not amenable to analytical solution. Though equations exist to describe the behaviour of each of the phases, the direct solution of these equations, for all but the simplest flows, is beyond current computer power. Because of this much work is being done to develop computationally tractable models which are capable of predicting the behaviour of these flows well. This thesis presents a new form of model based on a joint Eulerian-Lagrangian approach. This model is termed a transport model and consists of solving the second phase conservation equations in an Eulerian frame while introducing Lagrangian effects though a particle diffusion coefficient. This thesis consists of three parts. First the development of the method used to obtain particle diffusion coefficients is presented and tested against available experimental data. This is followed by a discussion of the Eulerian calculation procedure used for both the carrier and discrete phase. Finally the linking of the two calculation procedures is discussedin detail and the model's performance is evaluated against both experimental data and a range of other models found in the literature. The transport model is shown to perform well in predicting the chosen test-cases. Further, the results are shown to be comparable to, or better than, those of the other models considered. One of the main benefits of the model is its low computational overhead. All calculations presented here were performed on a desktop personal computer. Finally some recommendations are made for further work.