At Pr 1, conduction in an ordinary fluid flowing through a heated pipe is limited to the
A)Buffer zone
B)Turbulent core
C)Both (A) and (B)
D)Viscous sub-layer

Question

At Pr > 1, conduction in an ordinary fluid flowing through a heated pipe is limited to the
A)Buffer zone
B)Turbulent core
C)Both (A) and (B)
D)Viscous sub-layer

Quizplus · Accepted Answer

At Pr > 1, conduction in an ordinary fluid flowing through a heated pipe is limited to the viscous sub-layer. This is because the Prandtl number (Pr) is a dimensionless number that compares the rate of momentum diffusion to thermal diffusion. When Pr > 1, thermal diffusion (conduction) is slower than momentum diffusion, making the viscous sub-layer the primary region for conduction.

At Pr > 1, Conduction in an Ordinary Fluid Flowing