A transient computational fluid dynamics (CFD) model was developed to predict the hydraulics of a full open valve tray. The model studied the three-dimensional two-phase flow of gas and liquid in the Eulerian framework. Based on the clear liquid height measured on a full open valve tray, a new correlation of liquid hold-up was developed, and the interphase momentum transfer term was calculated. Several simulations were carried out for a rectangular full open valve tray with varying characters of system. The CFD simulations reflect chaotic tray hydrodynamics. The predicted results were in good agreement with the experimental data. (C) 2008 Elsevier B.V. All rights reserved.