FIGUREP$4\mathrm{.}37$

$4\mathrm{.}37$ A separate$-$flow turbofan engine is designed with an aft$-$fan configuration, as shown. The fan and core engine nozzles are of convergent design.

For simplicity, you may assume constant gas properties in the engine, i$.$e$.,$ let $$ be $1\mathrm{.}4$ and $c_p=1,004\frac{J}{k}g*K.$

Calculate

$($a$)$ ram drag $($in kN$)$

$($b$)$ compressor adiabatic efficiency ${}_c$

$($c$)$ shaft power produced by the high$-$pressure turbine in MW

$($d$)$ shaft power consumed by the fan in MW

$($e$)$ core net thrust in kN

$($f$)$ fan net thrust in kN

$($g$)$ thrust$-$specific fuel consumption in $m\frac{g}{s}\frac{?}{N}$

$($h$)$ engine thermal efficiency ${}_{th}$

$($i$)$ engine propulsive efficiency ${}_p$

Is there an obvious advantage to an aft$-$fan configuration? Is there an obvious disadvantage to this design?FIGUREP$4\mathrm{.}37$