Solution Manual Heat And Mass Transfer Cengel 5th Edition Chapter 3 [ DELUXE • CHEAT SHEET ]

A 2-m-diameter and 4-m-long horizontal cylinder is maintained at a uniform temperature of 80°C. Water flows across the cylinder at 15°C with a velocity of 3.5 m/s. Determine the rate of heat transfer.

$\dot{Q} {conv}=h A(T {skin}-T_{\infty})$

$\dot{Q}_{cond}=0.0006 \times 1005 \times (20-32)=-1.806W$

$\dot{Q} {net}=\dot{Q} {conv}+\dot{Q} {rad}+\dot{Q} {evap}$

The heat transfer from the insulated pipe is given by:

$\dot{Q}=h \pi D L(T_{s}-T_{\infty})$

$\dot{Q}_{conv}=150-41.9-0=108.1W$

Assuming $Nu_{D}=10$ for a cylinder in crossflow,