Question $1)[20$ Pts$]$

What is meant by the following?

A$)$ Prandtl number $[5$ Pts$]$

B$)$ No$-$slip boundary condition $[5$ Pts$]$

C$)$ Fully developed flow $[5$ Pts$]$

D$)$ Velocity boundary layer $[5$ Pts$]$

Question $2)[30$ Pts$]$

Oil enters a $2000-m$ long circular pipe at $2\mathrm{.}5$ bar and exits at $2\mathrm{.}25$ bar. The radius of the pipe is $2$ cm $.$ The viscosity and density of oil can be assumed to be constant and equal to $0\mathrm{.}009$ Pa $.$s and $850k\frac{g}{m^3}$ respectively. In case of fully developed laminar steady flow, estimate the following.

A$)$ Velocity at the centerline of the pipe $[10$ Pts$]$

B$)$ Reynolds number $[10$ Pts$]$

C$)$ Friction factor $[5$ Pts$]$

D$)$ Volumetric flow rate $[5$ Pts$]$