Air at $394\mathrm{.}3K$ flows through a packed bed of cylinders having a diameter of $0\mathrm{.}0127m$ and length the same as the diameter. The bed void fraction is $0\mathrm{.}4$ and the length of the packed bed is $3\mathrm{.}66m.$ The air enters the bed at $2\mathrm{.}2$atm abs at the rate of $2\mathrm{.}45k\frac{g}{m^2}.$s based on the empty cross$-$section of the bed. Calculate the pressure drop of air in the bed.