Abstract <p>The discrete model has been developed to describe the hydrodynamics of a fluid in a porous body. The model considers the heterogeneity and multiphase nature of the system, consisting of a solid body, air-filled pores, and liquid. The developed model is based on the lattice Boltzmann equation method together with the pseudopotential method for correct modeling of the liquid and gas phases in one system. To improve the accuracy of calculations at the interface, the Carnahan-Starling equation of state was used. Computational experiments were carried out to simulate the absorption of a test solution in the porous structure of hemostatic bandages based on chitosan aerogel at the mesoscale. The model input parameters corresponding to the system under study were selected, and the sorption capacity of the test solution for the experimental samples and the corresponding previously generated digital structures were compared. The calculated sorption capacity corresponded to the experimental one. The proposed model makes it possible to describe the hydrodynamics of a multiphase system, in particular, the movement of liquid in a porous medium and predict its sorption capacity. As a porous medium, the model uses digital porous structures obtained using the cellular automata approach. The model can use various equations of state such as the Van-der-Waals, Carnahan-Starling and Peng-Robinson equations to improve the accuracy of the simulation. In addition, the model allows you to work with multicomponent systems and is capable of describing the movement of a multicomponent liquid, in particular, blood and the active pharmaceutical ingredient dissolved in it. The model can be used in conjunction with other discrete models, in particular cellular automata, allowing the simulation of multiple processes in a single system, for example, the dissolution and movement of an active pharmaceutical ingredient in a porous medium.</p>