Akaflieg München Mü31

Mü31
	Akaflieg Munchen Mu31 at the ILA Berlin Airshow, 2016
Role	High-performance glider aircraft
National origin	Germany
Manufacturer	Akaflieg München
First flight	15 September 2017

The Akaflieg München Mü31 is a high-performance single-seat glider aircraft that is under design in Germany as of 2010.^[1]

Development

After completion of the Akaflieg München Mü30 Schlacro, students turned to the design of a new 15m-FAI racing class glider, with a maximum span of 15m (49 ft 3in), a maximum of 150 liters (40 US gallons) of water ballast and full-span flaps. Designated Akaflieg München Mü31, this glider is being designed to minimize interference drag between fuselage and wing root, with several variations being studied to select the ideal configuration:

planar wing in midwing configuration (conventional).
high-mounted wing with a swept wing root/fuselage transition.
high-mounted wing with turbulent flow at the joint between wing and fuselage.

These concepts were wind-tunnel-tested in 2006. The third configuration was deemed to be best. The resulting fuselage wing joint is similar to a pylon with the wing suspended by the leading edge, leaving uninterrupted flow at the trailing edge. This layout has the advantages of:

continuous upper wing surface

only two intersections between fuselage and wing as opposed to four in a more conventional mounting

turbulence created by the wing/fuselage joint does not disturb flow over the rear of the fuselage pod and boom

approximately elliptical lift distribution can be attained, reducing induced drag significantly.

To keep construction costs low, the Mü31 will be built using components from the Schleicher ASW 27, such as the forward fuselage, rear fuselage and tail and outer wings.

The Mü31 wings under stress testing

Specifications and projected performance (Mü31)

Data from Mü31^[1]

General characteristics

Crew: 1
Capacity: 150 liter water ballast
Wingspan: 15 m (49 ft 3 in)
Wing area: 9.0 m² (97 sq ft)
Aspect ratio: 25
Airfoil: DU 89-134/14, DU 94-086 M4
Empty weight: 240 kg (529 lb)
Gross weight: 500 kg (1,102 lb)

Performance

Maximum speed: 285 km/h (177 mph, 154 kn)
Stall speed: 67 km/h (41 mph, 36 kn)
Rate of sink: 0.50 m/s (98 ft/min)

References

^ ^a ^b "Mü31". Archived from the original on 2014-09-05. Retrieved 2012-06-10.

External links

Mü31 progress report

[Mü31-1] "Mü31". Archived from the original on 2014-09-05. Retrieved 2012-06-10.

[1]