How to solve...

Two similar flocculation tanks with a total design flow rate of $5200\frac{m^3}{d}$ have been designed to be operated in parallel. Each tank is $3\mathrm{.}0m$ deep $($inclusive of $0\mathrm{.}5m$ freeboard$),3m$ wide and $6m$ long. It is equipped with $2$ paddle type agitators. Each agitator has $4$ paddle blades and has a horizontal shaft perpendicular to the flow. Each paddle blade is $2m$ long and $0\mathrm{.}2m$ wide. All $4$ paddle blades are centred $1m$ from the centre of the agitator shaft. Each agitator is designed to rotate at $3rpm$ and the average velocity of the water is $30\%$ of the blade velocity. If the coefficient of drag $=1\mathrm{.}5$ and the dynamic viscosity of water is $1\mathrm{.}15{10}^{-3}k\frac{g}{m}.s,$ calculate for each tank :

i

the total paddle area,

iii the velocity differential for the paddle,

iv the average velocity gradient $($comment on this value$),$ and

$$ the power required.

$(2000/01$ SEM $1$ TERM TEST$)$