Validation of a two-fluid model on unsteady liquid–vapor water flows

Abstract

a b s t r a c tThis paper is devoted to the validation of a two-fluid two-phase flow model in some highly unsteady situations involving strong rarefaction waves and shocks in water-vapor flows. The two-fluid model and its associated numerical method that were introduced in a previous work are first recalled, and details on the computational scheme and the verification of interfacial mass transfer terms are provided. Consistency with experimental data is checked in three configurations. First, a comparison with the speed of sound in a two-phase mixture is detailed. Afterwards, numerical approximations obtained with the two-fluid approach are discussed and compared with some experimental data documented in the Simpson water-hammer experiment and the high depressurization with flashing associated with Canon experiment.

The investigation of gas–liquid two-phase transient flow based on Steger–Warming flux vector splitting method in pipelines

“…The specific heat ratio g k is given by g k = C p, k =C v, k , and as in the model by Crouzet et al, 15 p v is taken to zero and p l is computed as in equation (13) …”

“…The experiment consists of a horizontal pipe (which has 1 m high slope), upstream tank, and downstream valve. The fluid pressure is measured at three points along the 36 m pipeline which are located at 36, 27, and 9 m. The main parameters of fluid are referenced to the literature, 15 and the specific data are listed in Tables 1 and 2 The speed is set as the boundary condition for the calculation as shown in Figure 2, where the interval velocity between 1173 and 1424 ms is used to forecast mixed pressure changes at different points. As seen in Figure 2, there is a good agreement between the simulation and experimental value in the result of mixed pressure, with a slight deviation only at peak pressure, but they still follow the same trend in the pressure.…”

“…15 The analysis data from Simpson 26 are selected for calculation and comparison. The experiment consists of a horizontal pipe (which has 1 m high slope), upstream tank, and downstream valve.…”

“…The gas release process of air and a cavitation model are investigated to improve the overall method in this section. Some improvements are made in the calculation method of mass transfer through the interface based on the method used by Crouzet et al 15 to ensure that model is suitable for mass transfer in bubble flow.…”

“…The results have shown that a good agreement can be achieved using two-fluid model between simulation and experiment. [10][11][12][13][14][15] In this article, two-fluid flow model which was based on the hyperbolic part of the Saurel et al 12 was constructed 13,16,17 for transient simulation in pipelines. The investigation is demonstrated for following six parts:…”