Two-phase flows properties in mini-channels are a topic of academic and industrial interest, especially within electrolyser technology, as these can prove valuable in the future energy grid. As scientific work on validation between experimental and numerical VOF and Two-fluid model work on two-phase flows in squared mini-channels is lacking, this was chosen as the main focus of the thesis. A numerical and experimental two-phase test scenario was determined with air supplied at a constant superficial velocity of 0.7 m/s and water at a constant superficial velocity of 0.4 m/s. Based on the set test scenario, a experimental and numerical geometry was build and the volume fractions and pressure losses was chosen as the main parameters of validation. The VOF and Two-phase model was utilized for the numerical part of the thesis, whilst a Plexiglas T-junction cell, with optical access and pressure transducers, was setup for the experimental work. Results indicated, that the VOF modelling and experimental results were in best correlation with each other. However, it was also reasoned in the discussion, that errors in the numerical settings by the authors and uncertainties in the experiment, could prove to lower the overall actual error between the different methodologies.