Simulating particle collision process based on Monte Carlo method

Particle collision is non-trivial in many processes occurring in nuclear power system. A new particle collision algorithm has been carried out based on Monte Carlo approach under Lagrangian methodology. According to different collision kernel, the traveling time that a particle experiences between two neighborhood collision events is obtained in a more physical way than that in the current standard algorithm of O'Rourke. Besides, the outcomes of particle collision are acquired by proper collision models in choosing collision pairs, which are picked up by calculating the colliding times between two particles in each pair. To evaluate the performance of this new algorithm, first, a simulation for the total number changing with time of Brownian aerosols is compared with analytical solution. And the modeling result and the analytical formulation are in excellent agreement. Second, two mutual-impingement sprays are simulated by the new collision algorithm against that of O'Rourke. Then the modeling results are compared with experimental data, and it is found that the shapes of the mutual-impingement sprays obtained by the new algorithm are much better than that got by O'Rourke algorithm. Moreover, in order to investigate the working mechanism of the secondary moisture separator of AP1000, this new collision algorithm is applied to model the distribution of droplets moving in it. These modeling cases above show that the new collision algorithm is useful for numerical analysis, some kinds of particle-laden flows within particle collision process, such as sprays and droplet-steam flows, etc.