## Solved Problem 6.13 - T700 Proposed Turbojet
Conversion

Recall **Solved
Problem 6.11** in which we did an ideal
thermodynamic analysis of the General Electric T700 helicopter gas
turbine engine. During Fall Quarter 2008 Dr. Tom Scott (currently
retired) presented an inspiring and animated demonstration of the
cutaway T700 gas turbine engine as shown below:

During the talk he mentioned that one could unclamp
and remove the power turbine at the rear and replace it with a nozzle
to form a turbojet engine. This captured our imagination, hence we
would like to do an initial ideal thermodynamic analysis of this
conversion. Consider the schematic diagram of this conversion shown
in the figure below:

Notice that the *h-s*
diagram has retained the same shape and characteristics
as that in **Solved
Problem 6.11**, with the only difference
being that the change in enthalpy on the nozzle gives rise to a
kinetic energy increase, rather than work output.

On replacing the power turbine with an
isentropic jet nozzle, determine the temperature (T_{5})
and exhaust velocity (V_{5} - m/s).
Given that the mass flow rate of the working gas through the system
is 4.6 kg/s, determine the thrust force at the outlet of the nozzle
(Thrust_{5} - lbf). [Note: 1 lbf (pound
force) = 4.46 N]