Critical Speed

Flow speeds faster than the critical speed of a fluid result in turbulent flow. Speeds slower produce laminar flow

$v_c=\frac{N_R\eta }{\rho D}$

• $v_c$ is the critical speed in a tube
• $N_R$ is the Reynolds Number
• $\rho$ is the fluid density
• $D$ is the tube diameter
• $\eta$ is the fluid viscosity