New stealthy VTOL aircraft- more efficient and much faster

We are studying a new VTOL aircraft with an annular lift fan as shown in the picture. The aircraft is more efficient than helicopters with power loading of 7.4 lbs/hp (4.5 kg/kw) at the disc loading of 28.37 lbs/ft2 (138.5 kg/m2) without ground effect. When the distance from the aircraft to the ground is 10 m, the figure of merit reaches 0.832 with the power loading of 8.5 lbs/hp (5.2 kg/kw). The maximum cruise speed can reach 0.75 Ma, much faster than helicopters and tiltrotors. The aircraft is also stealthy and quiet. Here are the research articles:

http://www.mdpi.com/2226-4310/3/4/30
http://www.mdpi.com/2226-4310/2/4/555

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