Question $5.$ Torsion $($LO$3)$

$(10$ Marks$)$

A Gas Turbine has a maximum output power of $150MW$ at a speed of $2000rpm.$

A shaft of length $5m$ made of EN$8$ steel $($properties given in the table below$)$ is

to transfer torque from the turbine to electricity generator. Using a design

stress for EN$8$ Shafting as $480$MPa. You are to:

i$.$ Calculate the appropriate diameter $($in $mm)$ of a solid shaft, so that it will not

fail due to torsion.

$(6$ marks$)$

ii$.$ Calculate the angle of twist $($in degrees$)$ for the shaft during maximum output.

$(4$ marks$)$