Abstract :
The ability to flights an aircraft can be determined by the performance of
the aircraft engine and the aircraft's flights conditions. This study aims to
determine the effect of altitude on the performance of the T700-GE-700 turboshaft
engine used in the Sikorsky UH-60A black hawk helicopter. By calculating the
value of fuel air ratio, specific thrust, specific fuel consumption, thermal
efficiency, propulsive efficiency and overall efficiency as well as calculating the
value of induced power during hover conditions. This research was conducted
using four flights altitude, is 1000 ft, 2000 ft, 3000 ft, 4000 ft 5000 ft,, 6000
ft,7000 ft and 8000 ft.
Before know the values, some input parameter data is needed. And to find
out the value of fuel air ratio, specific thrust, specific fuel consumption, thermal
efficiency, propulsive efficiency and overall efficiency using parametric cycle
analysis and engine performance analysis methods, while to determine the value
of induced power uses the equations contained in the momentum theory.
The results obtained from this study are that altitude is very influential on
the performance of an engine where the value of fuel air ratio, specific thrust,
thermal efficiency, propulsive efficiency increases with the increase in flying
altitude. This is due to the influence of the value of temperature, air density and
air pressure at each altitude, but the specific fuel consumption value has
decreased because the size of the specific fuel consumption value is determined by
the value of the fuel air ratio and the value of specific thrust. For the value of
induced power, the actual induced power value is greater than the ideal induced
power it is due to the influence of the drag value.