Multiphase flows are often present in chemical processes and they include gas-liquid transport, which may become intermittent depending on the operating conditions. One type of flow structure is the presence of large gas bubbles that can occupy the entire duct diameter, separated by liquid portions. This can result in large pressure fluctuations, which are normally associated with damage to equipment over time. The intermittent nature and the chaotic distribution of the phases in a turbulent flow complicate the design and optimization of the equipment. In this context, computational fluid dynamics is a useful technique since it can provide important information on several flow conditions, but the use of suitable models and boundary conditions is required. In this study, an air and water flow with the presence of slugs is evaluated in a system consisting of horizontal and vertical ducts, with an inner diameter of 94 mm. Experimental data on the pressure and void fraction were analyzed and compared to the predictions obtained from numerical simulations, obtained considering the VOF approach. It was observed that the use of the geometrical reconstruction scheme to simulate a compressible flow resulted in a better agreement with the experimental results. Using this setup, the average volume fraction and pressure values showed the expected behavior. The frequency of slugs, established using three different methods, was around 1.5 Hz for the evaluated conditions evaluated. The pressure probability density function (PDF) indicated good agreement between numerical simulations and experimental data, while the volume fraction PDF indicated that the flows evaluated have the characteristics of a churn flow regime. Moreover, it was found that an increase in the water flow rate can lead an increase or a decrease in the average velocity. (C) 2018 Elsevier Ltd. All rights reserved.