helpQUESTION $1$

A computer cooled by a fan contains eight $(8)$ printed circuit board $($PCBs$)$ in Figure, each

dissipating $10W$ of power. The height of the PCBs are $12cm$ and the length are $18cm.$ The

gap between the two PCBs is $0\mathrm{.}3cm.$ The cooling air is supplied by a $25W$ fan mounted at the

inlet. The temperature rise of air as it flows through the case of the computer is not to exceed

$10C.$ Evaluate the highest allowable inlet air temperature when the surface temperature of the

components is not to exceed $70C$ anywhere in the system. Discuss your finding. Assume air

properties at $27C.($Ans: $V=3,058\frac{m}{s},Re=1145,T_e=61\mathrm{.}6C,T_i=51,6C)$