## Flow Type

A Newtonian fluid with a dynamic viscosity of 0.05 lb/(ft∙s) and a density of 500 lb/ft^3 flows through a 0.25 ft diameter pipe with a velocity of 2 ft/s. Is the flow through the pipe characterized as laminar, turbulent, or transitional?

Expand Hint
Flow through a pipe is generally characterized as laminar for Re < 2,100, fully turbulent for Re > 10,000, and transitional flow for 2,100 < Re < 10,000.
Hint 2
The Reynolds number for a Newtonian fluid:
$$Re=\frac{vD}{\nu }$$$where $$v$$ is the fluid velocity, $$D$$ is the pipe diameter or the fluid stream dimension or the characteristic length, and $$\nu$$ is the kinematic viscosity. The Reynolds number for a Newtonian fluid: $$Re=\frac{vD\rho}{\mu}$$$
where $$v$$ is the fluid velocity, $$D$$ is the pipe diameter or the fluid stream dimension or the characteristic length, $$\rho$$ is the mass density, and $$\mu$$ is the dynamic viscosity (or absolute viscosity).
$$Re=\frac{(2ft/s)(0.25ft)(500lb/ft^3)}{0.05\frac{lb}{ft\cdot s}}=\frac{250}{0.05}=5,000$$\$
Flow through a pipe is generally characterized as laminar for Re < 2,100, fully turbulent for Re > 10,000, and transitional flow for 2,100 < Re < 10,000.

Since $$2,100<5,000<10,000$$ , the flow is characterized as transitional.
Transitional
Similar Problems from FE Sub Section: Reynolds Number

Similar Problems from FE Section: Fluid flow characterization