Next approximation of the random walk theory for Brownian coagulation

The new approach to Brownian coagulation theory, developed in the authors’ previous papers and based on the simple random walk theory (with a fixed elementary walk distance of migrating particles), is further improved by more realistic consideration of random walks with stochastically distributed lengths. The interpolation expressions derived in the simple random walk approach avoiding semi-empirical assumptions of the traditional models, are justified (within the calculation accuracy) by new calculation results obtained in the next approximation of the random walk theory. The developed approach being applied to the problem of heavy vapour molecules condensation in a large trap, results in the improved description of the condensation rate in the transition regime.

► The authors’ simple random walk approach to the Brownian coagulation theory was further improved. ► Random walks with stochastically distributed lengths are considered. ► New interpolation expressions derived in the simple random walk approach are justified. ► The approach is applied to the problem of heavy vapour molecules condensation in a large trap.