• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.6
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• pp.83-90
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• 2017

Performance analysis of the turboshaft engines for combined rotorcraft was executed. A tip jet and a ducted fan aircraft were selected for combined rotorcraft application. Gasturb 12 software was used for turboshaft engine performance analysis. In the results, maximum required power for the tip jet engine is about 1,600 hp class and maximum required power for the ducted fan engine is about 1,000 hp class at the required aircraft mission. This is due to the additional power of the auxiliary compressor to get a bleed air mass flow rate for the tip jet operation. At the same time, fuel consumption of the tip jet aircraft is 2.8 times larger than ducted fan case. Therefore ducted fan type aircraft is more efficient than tip jet aircraft in terms of fuel economy.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.5
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• pp.413-422
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• 2012

The ducted fan for a small UAV propulsion can reconnoiter and observe in a town and a small area, it has better thrust efficiency and a long endurance than propeller. Thrust characteristics of hover and for ward flight condition for the ducted fan UAV is important issue to improve a endurance. The unsteady 3-dimensional flow fields of the ducted fan UAV is essential to stable flight. In this paper, to verify the design results of the ducted fan and to investigate a stable aeronautical characteristic, the thrust performance and the unsteady 3-dimensional flow fields are measured. Thrust characteristics for the hovering and the forward flight conditions are measured by the 6-components balance system in the subsonic wind tunnel. The unsteady 3-dimensional flow fields are analyzed by using a stationary $45^{\circ}$ slanted hot-wire technique. The swirl velocity is almost removed behind the stator blades. Therefore, the thrust performance of the ducted fan is improved and the flight stability is maintained.