Numerical analysis of one-dimensional, two-phase flow in a vertical cylindrical passage

Abstract This paper presents a one-dimensional, isothermal, flow analysis of steam and water mixtures in vertical flow passages, of the type found in many engineering applications. Computations have been performed with the aid of a finite-difference procedure and by assuming, one by one, four different flow regimes, viz. bubble, dispersed (droplet), annular and inverse annular. The predictions obtained for the different flow regimes are compared, and found to be significantly different from each other, as expected from physical considerations. It is concluded that the correct specification of flow regimes is important in two-phase flow computations, that the steady-state results obtained are in agreement with existing simple models and that the present numerical procedure is stable and efficient.