Rhein-Flugzeugbau Sirius
| Rhein-Flugzeugbau Sirius | |
|---|---|
| Type: | Motor sailer |
| Design country: | |
| Manufacturer: |
Rhein-Flugzeugbau GmbH (Mönchengladbach) |
| First flight: |
Sirius I: April 1968 / Sirius II: January 18, 1972 |
| Number of pieces: |
2 |
The Rhein-aircraft Sirius was a motor sailer of the West German manufacturer Rhein-Flugzeugbau GmbH. The special feature was the drive used by two Wankel motors , which together drove an integrated ducted propeller.
history
Following on from the development of the Rhein-Flugzeugbau RF-1 Channelwing aircraft in 1960, Rhein-Flugzeugbau (RFB) carried out extensive basic research into propulsion using a jacket propeller integrated in the fuselage, also known as jacket screw, from the mid-1960s. The technical director of RFB Hanno Fischer and Hans Aichert from the University of Stuttgart were decisive for the developments . Aichert dealt with the design of the jacket screw drive, while Hanno Fischer looked at the integration of the jacket screw drive in the aircraft. In order to be able to use jacketed screw drives at both high and low speeds, Aichert u. a. a pre-ring that opened or closed depending on the pressure curve. When asked about the arrangement of the jacketed screw drive in the aircraft, Fischer decided, as with the RW-3 and RF-1, for a pusher propeller solution in order to avoid jet losses when blowing on the fuselage and the wing connections. Fischer also examined different hull shapes of the cabin in front of the jacketed screw drive and different wing arrangements. Fischer summarized the results of these investigations in his patent DE1506089A1 "Airplane, in particular motorized glider, with propeller drive" in October 1966.
Construction and testing
The Sirius was a test vehicle and its design was significantly changed several times, particularly in the area of the jacket screw and the drive. A second Sirius test vehicle, Sirius II, was created in the 1970s to compare high and low-lying horizontal stabilizer surfaces.
Sirius I
For testing purposes, a test vehicle was created at Rhein-Flugzeugbau in 1969 under the name Rhein-Flugzeugbau Sirius. Instead of a completely new design, when building the test vehicle, Fischer resorted to the all-metal glider FK.3 from RFB parent company VFW-Fokker , which was designed by Otto Funk and first flown in Speyer in April 1968. The wing and tail were taken over unchanged from the FK.3. Behind the cockpit, an engine compartment for 48 hp, air-cooled Nelson two-stroke engine and the jacket screw was used. The Sirius test vehicle received the D-KIFB approval and was first flown by Hanno Fischer in Mönchengladbach in May 1969. After the first flight, the conversion to two Fichtel and Sachs rotary engines with 20 hp each took place in the same month. The Sirius was presented to the public in this configuration at the Aero Salon in Paris in 1969. The first test vehicle, later called Sirius I, was subjected to intensive testing in 1969 and 1970, during which the integration of the jacket screw was changed several times.
Sirius II
From 1971 Fischer dealt with the effects of the jet stream on the tail unit. In 1971, a second test vehicle named Sirius II based on a two-seater Caproni-Vizzola A-21 Calif was created to compare high and low-lying horizontal fins . With the two seats arranged side by side, the A-21 was able to test the effect of wide cabin hulls on the jacketed screw drive at the same time.
The Sirius II was powered by two 30 hp rotary engines. The first of the two rotary piston motors used for the drive was located in front of the rotor of the ducted propeller, while the second motor, consisting only of a disc with its own carburettor, was arranged behind the first motor. The ignition was done by the second ignition circuit of the front engine. This should prevent a total engine failure due to ignition reasons. If one ignition circuit failed, the power was only halved, and a further flight without loss of altitude was still possible at a maximum of 110 km / h.
A special feature of the integrated jacketed screw drive is the flight characteristics, which should come close to those of a jet aircraft. The acceleration curve is similar to that of a jet, there is also no torque generated around the vertical axis and the rudders remain free from propeller jet influences .
The machine (registration D-KAFB) took off on January 18, 1972 from the RFB works airfield in Mönchengladbach on its maiden flight.
Exhibitions and whereabouts
In May 1972 the Sirius II was presented to the public at the ILA 1972 in Hanover. At the Farnborough Air Show 1972, the Sirius II was offered on data sheets of the RFB subsidiary Sportavia-Pützer . However, there was no serial recording of the Sirius II at the Sportavia, which specializes in wood construction. The two Sirius test vehicles remained individual pieces that were stored in Mönchengladbach a short time later. At the 1972 ILA in Hanover, RFB announced the follow-up design for a motorized aircraft with jacketed screw drive under the designation AWI-II, which would later become the Rhein-Flugzeugbau Fanliner. The jacket screw based on the Aichert principle was later used by RFB as part of the SG push frame.
Technical specifications
| Parameter | Sirius I | Sirius II |
|---|---|---|
| crew | 1 | 2 |
| length | 7.35 m | 8.04 m |
| span | 17.54 m | 20.38 m |
| height | 1.80 m | 1.80 m |
| Wing area | 13.80 m² | 16.10 m² |
| Wing extension | 25.80 | |
| Glide ratio | 40 | |
| Max. Takeoff mass | 460 kg | 690 kg |
| Minimum speed | 72 km / h | |
| Top speed | 250 km / h | 270 km / h |
| Rate of climb | 2.0 m / s | |
| Take-off run | 200 m | |
| Range | 250 km | 270 km |
| Engines | 1 Nelson 48 hp | 2 rotary engines with 22 kW (30 HP) each |
See also
literature
- First flight of Sirius II , Flug Revue March 1972
- Paul Zöller: Rhein-Flugzeugbau GmbH and Fischer Flugmechanik . 1st edition, 2016, BoD-Verlag, ISBN 978-3-7431-1823-2 .
Web links
- Photo of Sirius I
- Photo, dates of Sirius II (French)
- Photo of the two coupled motors
- Flight International, Jun 12, 1969 - 3D sketch of the Sirius jacketed screw drive
- Flight International, 01 Nov 1973 - Replacing the Propeller
- Jet glider concept - principle of the jacketed screw drive , January 2003
Individual evidence
- ↑ Hanno Fischer: Airplane, especially motorized glider, with propeller drive . DE1506089 A1, October 7, 1966 ( google.com [accessed June 25, 2017]).
- ↑ Flugrevue: First flight of Sirius II . March 1972.
- ^ Paul Zöller: Rhein-Flugzeugbau GmbH and Fischer Flugmechanik , 2016, ISBN 978-3-7431-1823-2
- ↑ RFB / Sportavia product folder Sirius
- ↑ RFB product folder Sirius II