a$)$

An important dimensionless group for centrifugal pump performance analysis is the flow coefficient,

$\frac{Q}{d^3}.$ A pump with an impeller which has an outer diameter of $d=0\mathrm{.}3m$ delivers a volume flow rate

of $Q=0\mathrm{.}5\frac{m^3}{s}$ when running at an angular speed of $=180ra\frac{d}{s}.$ What is the flow rate in $\frac{m^3}{s}$

for a geometrically similar pump which has an impeller with an outer diameter of $d=0\mathrm{.}28m,$ and is

running at $=300ra\frac{d}{s}?$

$0\mathrm{.}78$

$0\mathrm{.}47$

$0\mathrm{.}68$

$0\mathrm{.}54$

None of the answers provided

Expected answer:

$0\mathrm{.}78$

$0\mathrm{.}47$

$0\mathrm{.}68$

$0\mathrm{.}54$

None of the answers provided