Flow can be both countable, and uncountable. See https://simple.wiktionary.org/wiki/flow Ellen gave some countable examples. "More flow results in more blockages". "Increased heat increases blood flow". "You need to analyse electrolyte flow between the electrodes".

Thank you!

Hi Lang. Flow may be used as an uncountable or countable noun. More often it will be uncountable and even when countable it may still be spelled 'flow' adding to the confusion. Examples of a plural usage: "The data tracks various types of flows." or "The lava flows are quite dangerous." Hope this helps. e.