R. Caulkin A. Ahmad M. Fairweather X. Jia R. A. Williams An investigation of sphere packed shell-side columns using a digital packing algorithm. 1715-1724 2007 31 Computers & Chemical Engineering 12 http://dx.doi.org/10.1016/j.compchemeng.2007.03.014 db/journals/cce/cce31.html#CaulkinAFJW07