"Unidirectional flow" refers to the movement or transfer of something in a single direction only, without any backtracking or reversal. Full definition
Heart valves are thin flaps of tissue in the heart, which ensure unidirectional flow of blood between the four chambers during the cardiac cycle. (sciencedaily.com)
In freshwater applications, they are best employed in rheophilic habitats where the fish need a constant unidirectional flow of water to simulate their natural ecosystems — for example, the Congo (Zaire) River and the up - stream habitats of the Asian hillstream regions. (petbusiness.com)
As suggested by the SLP analyses above, in 2008 winds came from different directions in different months, in contrast to the more unidirectional flow in 2007. (searcharcticscience.org)