Study On Numerical Simulation Of Dense Gas-Particle Two-Phase Flow

Multiphase flows exists all around in the natural world and is wide applied in the fields of industry, agriculture, national defence and environmental protection, etc. In the recent twenty years, multiphase technique has permeated into each branch of our national economy. Especially, it has been becoming important technology or the most advanced branches of technology. It is extensive and deeply important to study the multiphase flows, and the government and the researcher have been paying much attention to it. Under this history and reality background, it is made a great advance to study multiphase flows in recent twenty years, and it has been establishing a relative complete theory system, and it was also made a greatly successful to guide the practical engineering.As we know, study of two-phase flows is the foundation and the forward position of the study of multiphase flows, and it is mainly the study of gas-solid two-phase flows to study two-phase flows. Especially, the dense gas-solid two-phase flows is the forward position of study ^as-solid two-phase flows. At present, it is only a few reports on the study of dense gas-solid two-phase flows, and the main problem is how to consider the interaction between the particle to particle and particle to fluids in the flows.Based on the thoroughly review and summary in the progress history of the multiphase flows researching in recent fifty years, the thesis was made an advanced discussion on the wide foreground of the multiphase flows' study and application, and clarified some concept of multiphase flows' study. Take gas-solid two-phase flows for example, the thesis discussed and classified the theoretical model of multiphase flows' study, that is continuum model, discrete particle model and pseudo particle model, and made a deep and detail discussion on the foundation, advantage and disadvantage about the three physical model. The thesis considered that all the mathematics models of the multiphase flows' study are based on the three physical models. Thus, we got more clearly understand about the essence, advantage and disadvantage, and the direction of study in future of the various mathematics models. After this, the thesis raised a new combined mathematics model which based on the E/E model (basing on the continuum physical model) and E/L model (basing on the discrete particle physical model). The new combined model solved the problem of that the E/E model can't use to simulate the flows that exists phase change, and the E/L model needs infinite computer time to simulate the real flows. In a general way, the new model brings forth-new ideas to us, and it is important to multiphase flows' study and the application in engineering.The thesis considered that the particle kinetic theory is the kernel of the E/L model, and it is also the one of the most advanced branches of the new combined model. Advanced research and develop the particle kinetic theory, and establish a real and accurate model of the interaction between particle to particle and particle to fluids in the flows, thus we may use the new combined model to simulate the real gas-solidtwo-phase flows. In addition, the thesis considered that the pseudo particle model should be used to simulate the microstructure of the multiphase flows. By study of the microstructure of the multiphase flows, we may get a real and accurate model of the interaction between particle to particle and particle to pseudo particle in the multiphase flows, and then may make a great progress in multiphase flows research by using the new combined model.Finally, the thesis employed the new combined model to simulate the dense gas-solid two-phase vertical flows, to simulate the dilute or dense gas-solid two-phase jet flows, and both of them got a satisfied numerical solution. After comparing the numerical results to experimental data, we found that they were quite agreement. It proves that the new combined model is right, accurate and reliable, and it may be suitable to simulate various dense gas-solid multiphase flow...