Comparisons of formulations of multiphase flow

Abstract Methods of approach toward the formulation of the dynamics of multiphase flow include those of single free particles, continuum mechanics including interfaces with volume and time averaging, and statistical averaging. Unresolved aspects are transfer integrals and stress systems. Basic premises and experimental bases are compared. Physical meanings of mathematical operations are discussed. Challenges in the determination of transfer integrals or sums and transport properties of phases in the mixture are identified.