Simple models, based on liquid-solid and gas-liquid interaction are proposed in order to model a gas-liquid flow in trickle-bed reactors operating in high interaction regimes. Good results are obtained, when the liquid-solid and the gas-liquid interactions are modeled separately. Besides the classical Ergun equation, a simple model of the liquid-solid interaction, based on a boundary layer flow is proposed. This approach results in a relation which is very close to the well-known liquid saturation correlation proposed by Specchia and Baldi (1977, Chem. Engng Sci. 32, 515-523), and might be its theoretical justification. The gas-liquid interaction is modeled using a drift-flux approach. The different models are tested against the data bank of about 1500 saturation and pressure drop measurements, established mainly by the Nancy research group. The importance of the geometrical characteristics of the porous media and their incomplete description are emphasized. Finally simple predictive correlations based on the models are proposed, tested against the data bank and compared to literature correlations.