QUESTION $1$

Aviation fuel flows through a smooth circular pipe of diameter $20$mm at a temperature of

$250$C$.$ The sp$.$gr$.$ of the fuel at this temperature is given as $0\mathrm{.}94.$ Volume flow rate of oil

through the pipe is measured as $0\mathrm{.}9$ lit$/$min$.$ Determine the Reynolds number and type of

flow for these above conditions. Due to the adjacent hot equipment, the temperature of

the oil increases to $500$C while flowing through the fuel pipe. The sp$.$gr and the viscosity

gets reduced by $11\%$ and $15\%$ respectively for fuel compared to $25$

$0$C$.$ Determine the $\%$

change in the Reynolds number and type of flow. The dynamic viscosity of fuel is

measured as $1\mathrm{.}95$x$10-3$ Pa$.$s at $250$C$.$