Rolls-Royce Thrust Measuring Rig
The Rolls- Royce Thrust Measuring Rig (TMR ) ( German: Thrust measurement frame ) was an experimental VTOL aircraft from the 1950s to explore the use of jet engines for vertical take-off and landing and the use of this technique in a supersonic aircraft. (: Flying bedstead German ) referred to in the contemporary press, the suspension frame was because of its unusual appearance as Flying Bedstead.
History
The planned supersonic VTOL aircraft would have a number of vertically integrated jet engines installed for vertical take-off and suspended state until the wings were able to develop sufficient aerodynamic lift during the transition to horizontal flight. During this transition process, ensuring stability and the use of new artificial organs control was necessary, which should be designed with the aid of the TMR. The device should also show whether the regulation of the amount can be made solely by means of the lift engines. The design of supersonic aircraft and the proposal for the TMR go back to Alan Arnold Griffith. This later designed also a 44 -seat supersonic jet with 56 Rolls -Royce RB.162 - Hubtriebwerken and 12 engines for the horizontal drive.
Two Thrust Measuring rigs were built, which formally RAF serial numbers were allocated and XJ314 XK426. The first flight tests of the TMR were tied behind his Rolls- Royce belonging Hucknall Airfield near Derby in a gantry crane - like structure instead. This, a steel structure was built on a concrete base, which consists of two 18.30 m (60 ft) high columns and a 21.35 m (70 ft) was composed long crossmember. A suspension mechanism preventing a too rapid sinking of the device, in addition attended four ropes on the sides ensure that the TMR could not move out of the device. The first flight we reached a height of 6.10 m. The first free flights were carried out from August 3, 1954 with regular heights of about 45 m were flown. Was critical that the floor only a rolling maximum speed of 8 km / h was allowed because otherwise threatened a rollover of the device because of the small wheels and the high center of gravity. Because the only effective roll control low -offs were made in crosswinds always with the nose or tail into the wind, to use the very fast reacting pitch control when lifting can.
Over a period of five months, 23 flights were conducted. Eight more flights were made in Farnborough.
Construction
The TMR had two Rolls- Royce Nene jet engines that were horizontal " back -to-back " installed. The gas outlets were bent by 90 ° downwards, so that the thrust vector of both engines went through the center. In order to prevent failure of one engine rolling or pitching of the device, additional measures were required. The outlet of the front engine was to split in two, down left and right of the single outlet of the rear drive. For each engine had a separate tank, each with 431 liters (95 gallons) available, which were sufficient for a flight duration of about 10 minutes.
On a platform above the drive units of the pilot's seat and auto- stabilization system was arranged with its batteries. Sat the pylon structure under which the pilot, served initially as suspension for the bound flights and later in a reinforced version for the free flights as a protection event of a rollover on the floor. The four-legged chassis could accommodate shocks to a vertical speed of 11 m / s. The height control was only on the power lever, whereas the other controller via compressed-air outlets of the front pipe arms, has been made at the rear and on both sides. The rudder pedals operated cable with which the pivoted arm with the outlet nozzles and rotation could be achieved by the vertical axis.
The compressed air for movements about the transverse and roll axis was removed out of the two compressors of the engines in several places and collected respectively through a tube having a gradually increasing over the circumference of diameter and provided to a located below the pilot's pressure vessel. The compressors used on 9 % of their capacity to deliver at a pressure of about 12 bar an air mass flow of 7.3 kg / s. The pressure vessel had two valves, one for the pitch and roll of the controller, both of which are controlled by the car stabilizer. In neutral position and horizontal flight, the pitch control produced a thrust of 1.3 kN, respectively. In disorders of the flight, such as a lowering of the nose by turbulence, two electric motors are started automatically, which operated according to the valves and freely gave more compressed air for the front nozzle. The valves responded very quickly with a response time of only 0.3 seconds from neutral to full deflection. The pilot had no mechanical connection to the controller, with the control stick he operated only a rheostat which changes the voltage applied to the summing amplifier of the voltage stabilization system. The lateral control operated in the same manner, only the thrust nozzle with 40 lb was significantly lower.
The thrust / weight ratio was only 1.08 at the start, ie the generated thrust for the lift on the vehicle weight increased only slightly. Due to the fuel consumption during the flight, however, the TMR was lighter by 60 kg each minute, thus this ratio, and hence the flight behavior improved significantly.
Aftereffect
The results of flight tests with the TMR led to the development of the first engine, which was specifically designed for a vertical installation in jet-powered, horizontal takeoff tiltrotor aircraft. The Rolls- Royce RB.108 was then used for the first time in the experimental aircraft Short SC.1. In the Soviet Union, designed by Aram Rafaeljants and VN Matveev and designed after the model of the TMR Turboljet (also Turbolet ) was built in 1957. This suspension frame had as driving an AM -3 engine. The vehicle is on display at the Central Museum of the Air Forces of the Russian Federation.
Whereabouts
The second copy of the TMR ( XK426 ) was destroyed in 1957 in an accident. The XJ314 is now in the Science Museum.