Reynolds criterion

Reynolds criterion

[′ren·əlz ‚krī‚tir·ē·ən] (fluid mechanics) The principle that the type of fluid motion, that is, laminar flow or turbulent flow, in geometrically similar flow systems depends only on the Reynolds number; for example, in a pipe, laminar flow exists at Reynolds numbers less than 2000, turbulent flow at numbers above about 3000.