The dependence on viscosity means that the Reynolds number only makes sense for Newtonian fluids. Laminar flows have Reynolds numbers below 2100. The magnitude of the Reynolds number is independent of the system of units. Velocities in Turbulent Flow Consider a single particle of fluid moving in a turbulent stream. The particle will have its own instantaneous velocity with components in all directions, often moving differently from the bulk flow of the stream.
Turbulent flow is an example of a chaotic, nonlinear function.
In turbulent flow, all three velocity components will look similar, unlike in laminar flow when only one component is nonzero. Detailed treatment of turbulence requires a statistical approach. The frequency distribution of a velocity component is Gaussian. Need figure showing bulk vs. instantaneous The time averaged velocity does a good job of describing bulk flow, but doesn't precisely account for instantaneous behavior. This is done by expressing the instantaneous quantities as the sum of the average value and the instantaneous deviation from the average.