Rise of aqueous foam in vertical pipes

In this work we made many experiments on aqueous foams formation, the generation is done through a constant flow of gas from the bottom of the tube, by means of a capillary, we observed two cases, the first case was with the top tube open to the atmosphere and the second case is the same tube now covered. We measure vertical profiles of the foam rise velocities. These velocities are affected by properties of the foam solution and the interaction with the material tube as the surfactant type, angle contact, the type of foam generator, and different diameter of the pipe.