Plug flow of yoghurt in piping as determined by cross-correlated dual-plane electrical resistance tomography

摘要

Cross-correlation of electrical resistance tomography (ERT) was used to determine the velocity profile of yoghurt in a pipe of industrial dimensions. In viscometry, at shear rates higher than 10 s~(-1), the yoghurt followed the power law model with a K-value of 3.7 Pa s~n and an n-value of 0.37. In pipe flow, however, within the tested mean velocity range of 0.05-0.25 m s~(-1), the yoghurt appeared to flow as a plug. The local velocity was constant from the centreline to within 3 mm of the tube wall, which corresponds to the resolution of the ERT method.