A time dependent 3D numerical model for the behavior of flexible curtain in water was proposed, which is composed of two-way coupling of fluid flow calculation by SMAC method and simple model of curtain structure. The curtain structure is approximately described as an unclosed polyhedron with ribs and nodal points traveling on flow field creating restoring force which is taken into account for flow field calculation. The calculated deformation of suspended curtain in uniform flow agrees with that of predicting formula by ODA et al. (1996) to prove the accuracy of the model. A trial to reproduce the behavior of frame-type curtain in driven flow by vertical movement of horizontal flat plate was made to examine the applicability of the model for unsteady problems.
