Formulation of the fluid-solid interaction force for multi-dimensional, two-phase flow within tube arrays

In this paper for two-dimensional, homogeneous, two-phase flow, we present a formulation as a flow resistance matrix and the required experimental steps to define all elements of this matrix. Furthermore, an interim expression for the matrix is proposed for use pending development of the complete flow resistance matrix. As an example of the use of the interim expression, the case of a PWR steam generator is considered, and a complete definition of the formulation for this case is presented. (orig./RW)