Question $1[20$ marks$]$

A radial flow pump delivers water $($at $20\backslash$deg C$)$ at the volumetric flow rate of $0\mathrm{.}015$

m$3$

$/$s$.$ The rotor angular speed is $1470$ rpm$.$ The impeller has a uniform blade

height of $15$ mm$,$ with an inlet diameter of $70$ mm and exit diameter of $120$ mm$.$

It has backswept blades with a relative exit flow angle of $-50\backslash$deg $.$ The blade

blockage at exit is $8\%.$ The actual head rise of the flowing water is $4$ m in the

pump.

$($a$)$ Calculate the tangential component of the absolute velocity of water at

the exit from the impeller. $[7]$

$($b$)$ Calculate the power required to drive the pump. $[4]$

$($c$)$ Calculate the relative flow angle of water at the inlet to the impeller. $[5]$

$($d$)$ Calculate the efficiency of the pump. $[4]$