A Solution Scheme for Aerosol Transport Models

Abstract

Several computer codes are in use to solve the equations describing the behaviour of nuclear aerosols released during postulated accidents in water-cooled reactors. The algorithms are usually described as Method of Moments, Finite Difference Method, or Finite Element Method. A detailed study determined that all of these algorithms are special cases of a general method, the Method of Weighted Residuals. Various schemes differ in their selection of basis functions to approximate the solution and the weight functions. Accuracy, stability and efficiency are desirable in a numerical scheme. The present work was undertaken to develop an algorithm with the desired properties described above. A procedure has been developed that is also a special case of the Method of Weighted Residuals. The underlying argument, however, imposes some restrictions on the basis functions and the weights to achieve stability and accuracy. These restrictions make the present method equivalent to the Galerkin procedure. Some features of the procedure make it also more efficient than the existing codes. The scheme will be illustrated by a realistic numerical example.