A new method for simulating aerosols Brownian coagulation based on finite active samples assumption

Aerosol dynamics are of great importance in the concept of Leak Before Break (LBB) in the Nuclear Power Plant (NPP). Coagulation is of common interest due to its influence on the particle size distribution and number concentration during the diffusion process. In this paper, a new method for simulating aerosols Brownian collision and coagulation based on Monte Carlo algorithm and Finite Active Samples Assumption (MC-FASA) is proposed, and the corresponding software is developed. This MC-FASA method can directly simulate the collision process and obtain the coagulation coefficient as well as the time evolution of particle size distribution and number concentration. The method can reduce the computation amount without the loss of accuracy. The results are validated by the analytical solutions both for the monodisperse and polydisperse aerosol particles. The method provides the confidence to cover more aerosol dynamic processes in the coolant leakage from the reactor coolant pressure boundary (RCPB).