An Approximate Method to Calculate the Collision Rates of a Discrete-Sectional Model

An approximate method is proposed to improve the computational efficiency of discrete-sectional representations of aerosol dynamics. The expense that is associated with the numerical calculation of intersectional conversion rates is reduced by using a binomial expansion of the nondimensional collision frequency function in the summand so that an analytical integral form for the inner collision summation is obtained. A considerable saving in computational expense is achieved in comparison with a double summation with a very small sacrifice in accuracy