Numerical and experimental investigations into the effect of gap between baffle and wall on mixing in an oscillatory baffled column

We report our numerical and experimental investigation of the effect on mixing of implementing 0, 2, 4 and 6 mm gaps between the outer edge of baffles and the inner diameter of an Oscillatory Baffled Column (OBC). Large eddy simulation and digital particle image velocimetry techniques have been used to obtain the flow patterns and quantify the flow field and turbulence, such as the velocity ratio, integral length scale and mixing time scale versus the oscillatory Reynolds numbers. It is shown that the global mixing intensity and the turbulence length scale decrease, while the Kolmogorov time scale increases with increasing gap size in the range of experimental conditions tested in this work, which suggests a need for new configuration of OBC with baffle gap for certain applications involving particulates. Copyright © 2004 by the authors.