Does it mean "continuous movement" like No 1 in this link: https://www.oxfordlearnersdictionaries.com/definition/english/flow_1?q=flow
Tracy Kidder spent a year embedded in a group of engineers, intimately observing it in operation. The unusually in-depth and close-grained story takes us directly to the symbolic roots of flow, spirit, and magic. Very few studies of teams can match Kidder’s rigor and attention to detail.
Source: https://books.google.com.vn/books?id=iRArDwAAQBAJ&pg=PA266