To finish my second academic year I have to make a training course, I choose it in the Microgravity Laboratory at the Castelldefels School of Technology (EPSC) of the Technical University of Catalonia (UPC). My report consists in study and compares the results obtained from different experiment with diameter of T-junction of 1 mm and 2.5 mm. And so see the influence injection diameter on the generation of minibubbles. In fact I have to make a biphasic flow rate between 2 fluids, air and liquid in microgravity conditions, and observe the minibubbles created thanks to this mixture in a T-junction which has 2.5 mm for the diameter. I have to analyze different velocities such as the velocities of bubble, unit cell, slug of liquid, gas and liquid. And from this data I make a data sheet thanks to Excel and graphs. Then I compared my results with results which had already done by PhD. Arias which had made his thesis on two-phase flows in microgravity conditions with a diameter of T-junction of 1 mm.