The researchers used corn starch aqueous suspensions (a non-Newtonian viscoelastic fluid) and glycerol-water mixtures (a Newtonian fluid) in their experiment
Scientists from Bengaluru-based Raman Research Institute, an autonomous institute of the Department of Science & Technology, Govt. of India, have found a new method to improve the transportation of fluids like chocolates, lotions, sauces by tuning the viscosity and elasticity of fluids during materials processing in the food and personal care products industries.
Usually the transport of fluids through pipelines involves displacement of a more viscous fluid by a less viscous one. This creates instabilities at the interface between the fluids which leads to complex patterns of intrusion of the former into the latter. The complex intrusion pattern results in impurities during the transportation. Hence instabilities need to be removed to ensure smooth transportation of fluids during processing.
The scientists have found that by changing the viscosity of the displacing fluid and the concentration-dependent elasticity of the displaced fluid, the instability can be reduced and the roughness of the interfacial pattern and the efficiency of displacement can be controlled.
The study can also help understand instabilities at the interface between two fluids which is essential in the design and enhancement of processes, like filtration and electrodeposition of metals, as also mixing and demixing of two phases like that of sugar and chocolate which can affect the texture and taste of the chocolate.