Using the open-source CFD package OpenFOAM to model bubble motion and deformation in viscous liquids
Dr Ching-Hsien Chen, Dr B Hallmark, Prof. J. F. Davidson
Project status: ongoing
The shape and motion of bubbles contained in a flow of highly viscous liquid passing through an orifice was modelled using the open-source computational fluid dynamics (CFD) package, OpenFOAM. The experimental work detailed on the previous page was used as a benchmark against which to compare an existing multiphase flow solver (compressibleInterDyMFoam) and the same version of that solver that contained modifications to the viscosity averaging method. Simulations were carried out on a 320-core Warewulf cluster built especially for this project using second-hand Supermicro servers (obtained from ITInStock - highly recommended!). As before, image analysis was used to obtain quantitative comparisons against experiment and simulation. Figure 1 shows a comparison between experimental work and four different simulation cases - one high resolution calculation using the existing solved and three cases at differing resolutions using the modified solver.
Figure 1: CFD versus experimental work
As can be seen from the images above, the existing solved (blue surrounds) does not capture the bubble shape particularly accurately, whereas the modified solver resulting from this project (green, purple and red surrounds) does so with an accuracy that increases with simulation resolution. The high resolution case (red surround) makes predictions of bubble shape and motion that are qualitatively and quantitatively very similar to those observed experimentally. More details, along with additional comparisons against expeimental data, can be found in this preprint, which will be submitted to the journal Chemical Engineering Science for consideration of publication.