Characterization of mixing phenomena in T-mixers using smartphone devices

One of the main hurdles for research accessibility lies in the availability of reliable instrumentation. In this regard, the use of common devices from daily life, like smartphones, is a promising possibility to support researchers’ efforts. Several authors have already proved the possible application of smartphone devices in different scientific fields. In the present work, for the first time, mixing phenomena inside a square cross-sectional T-mixer were thoroughly assessed by adopting the digital camera of a commercial smartphone. Several flow regimes were examined, namely vortex, steady symmetric engulfment and turbulent, encompassing a wide range of Reynolds numbers from 100 to 5350. The pure dilution of non-reacting species was studied through a digital colorimetric image analysis technique. For comparison, a professional digital single-lens reflex (DSLR) camera was also employed to capture the same phenomena. Clear criteria for the use of digital cameras and the applicability of the experimental technique were provided. Numerical simulations, either steady-state laminar or Large Eddy Simulation (Smagorinsky model), were carried out to support the analysis. Strengths and weaknesses of the adopted two-dimensional digital image analysis technique were marked providing useful indications in the spreading panorama of low-cost technologies in the academic and industrial fields.