Water forms open channels, whether natural or artificial, which are studied in phenomena as in a flood; in order to save the greatest number of important people; important variables are the velocity profile and the pressure. The estimation of these variables is proposed using numerical model which is solved for the separate phases of liquid and gas using the Navier Stokes equation and for the liquid-gas interface the volume of fluid method is proposed, with two elements are estimated in a global way (liquid-gas) as if there were only one component. The equations are solved using the finite volume method. In addition, a mesh analysis is performed according to the channel geometry; the mesh types are hexahedral and tetrahedral with a number of elements respectively of 16791 and 166500. The tests carried out show a wave phenomenon in which the velocity of the flow increases from 0.7 m/s to 2.12 m/s and from 0.05 m to 0.07 m in height. In addition, an oscillatory movement was discovered which generated pressure gradients that varied between 0.2 kPa to 0.5 kPa. Tests are also carried out with other types of channels in which dry zones are observed, which are redesigned to reduce costs.