Rolls-Royce RB.23 Welland
Power Jets W.2
In 1940 the Air Ministry placed a contract with the Gloster Aircraft Company for prototypes of a new twin-engined jet fighter aircraft to the requirement of F.9/40, this aircraft became the Gloster Meteor. At the same time Power Jets was authorised to design a new engine that was intended to power the same aircraft. The W.2 was built under contract by the Rover Car Company in the early 1940s. It was originally intended to be produced by Rover as the W.2B/23.
The W.2 was basically a larger version of Whittle's original flying design, the Whittle Supercharger Type W.1, or simply W.1, which flew in 1941 in the Gloster E. 28/39 experimental testbed aircraft. The engines used a single double-sided centrifugal compressor, or impeller, with the compressed air being taken off at several ports around the extreme outer edge of the compressor disk. They both used Whittle's "reverse flow" design, in which the flame cans (combustion chambers) were placed around the turbine to produce a shorter engine. This required the heated air to flow forward before reversing its direction to pass through the single-stage axial-flow turbine. For the W.2, the impeller was 19 inches (480 mm) in diameter and there were ten flame cans. Air was bled from the compressor and fed into the inner portion of the turbine for cooling. The entire engine weighed about 850 pounds (390 kilograms).
Whittle was constantly frustrated by Rover. He thought that that there was an inability to deliver production-quality parts, and became increasingly vocal about his complaints. Whittle accused Rover of "tampering" with the design of the engine in order to avoid patent fees and enable Rover to claim the design as their own, whilst Rover's development work was proceeding at a slow pace. Rover was losing interest in the project after the delays and constant harassment from Whittle. Earlier, in 1940, Stanley Hooker of Rolls-Royce had met Whittle, and later introduced him to Rolls' CEO, Ernest Hives. Rolls had a fully developed supercharger division, which Hooker directed, which was naturally suited to jet engine work. Hives agreed to supply key parts to help the project along. Eventually, in early 1943, Spencer Wilks of Rover met Hives and Hooker, and decided to trade the jet factory at Barnoldswick for Rolls' Meteor tank engine factory in Nottingham. A handshake sealed the deal.
Power Jets W.2/700
Active interest in jet propulsion was first shown by Rolls-Royce during 1938, when a department was established for the design of gas turbines. In 1939 the first projects were put in hand, and by 1940 test rigs for components had been set up. Towards the end of that year the company was making components for Whittle units on behalf of Power Jets, Ltd., and was undertaking the manufacture of turbine blades, casings, pumps and other components.
During 1941 a special test plant was installed, with a Vulture to drive the compressors.
Rover handed over a total of 32 W.2B/23 engines to Rolls-Royce as well as four "straight-through" W.2B/26 engines, developed by Rover's Adrian Lombard. Rolls-Royce named their engines, and the continuous flow of air through the jets inspired Hooker to name them after the flow of British rivers. The W.2B/23 became the RB.23 Welland (RB standing for Rolls Barnoldswick), and the W.2B/26 became the RB.26 Derwent. Adrian Lombard moved with the engines from Rover to Rolls-Royce. Stanley Hooker helped in the task of ironing out the remaining problems, and things soon improved. A flight-quality /23 was fitted to a Gloster G.40, an updated version of the E.28 that had flown the W.1, and was flown by John Grierson on 1 March 1943. Starting in April, the ratings had been improved to 1,526 lbf (6.79 kN) thrust, and passed a run at 1,600 lbf (7.1 kN) on 7 May 1943. The prototype F.9/40 was finally fitted with 1,700 lbf (7.6 kN) engines and was flown by Michael Daunt on 24 July 1943.
The first Rolls-Royce turbojet, known as the WR1, measured 54in in diameter and was designed for a thrust of 2,000 lb. Built primarily to demonstrate that the aircraft gas turbine could be made cornpletely reliable, it ran for some 35 hr. Two examples were built, but combustion trouble was experienced.
Rolls-Royce there upon assumed control of the W.2 project, with Frank Whittle and his small team at Power Jets acting in an advisory capacity. Together, they ironed out the problems with the W.2 and finally put the engine into mass production as the 1600lbf thrust Rolls-Royce Welland. These engines were installed in the Gloster Meteor F Mk1 and early F Mk3's and entered service in 1944.
Early in 1943 Rolls-Royce took over research on the W2B/23 unit from the Rover company, whose engineers had developed straight-through combustion; units of the type were installed in the Gloster E.28/39 experimental aircraft, and in the tails of two Vickers-Armstrongs Wellingtons. Like the earlier Power Jets W.1, the trombone configuration featured a simple double-sided centrifugal compressor, reverse-flow combustion chambers and an air-cooled axial-flow turbine section. The first Rolls-Royce/Whittle W2B/23 passed its 100-hr type-test in April 1943, and was given the name Welland; in June 1943 two were fitted in the Gloster F.9/40 (prototype of the Meteor), and by May 1944 Wellands were being regularly delivered for R.A.F. Meteors. The Welland had a reverse-flow combustion system, a maximum diameter of 43in and could develop 1,700 lb, although for the F9/40 it was at first derated to 1,450 lb.
The Halford H1 development was not held up like the W2/B hence it powered the the first Meteor to fly on the 5th March 1943 beating the Rover W2/B 23 powered DG205 by a week.
The first examples produced by Rover had serious problems with "surging", in which the speed of the engine would suddenly increase out of control. Maurice Wilks eventually delivered a solution, by adding a set of 20-vane diffusers to the exhaust area. This solved the surging, but they now found that they had serious problems with the turbines failing, due to heat. J.P. Herriot of the Air Inspection Department (A.I.D.) was sent to Rover to provide improved turbine materials, and soon the engine achieved a 25-hour test at 1,250 lbf (5.6 kN) in November 1942. Meanwhile, the prototype Gloster F.9/40, soon to be known as the Meteor, was ready for flight, although the engines were not. Taxi tests were started by test pilot Jerry Sayer while the flight-quality engines waited. A real flight-test of the engine itself took place on 9 August 1942, fitted in the tail of a Vickers Wellington bomber.
Two Wellands were installed in the first production Meteor Mk.1, Serial number EE210/G, (the "/G" signifying "Guard", meaning that the aircraft was to have an armed guard at all times while on the ground) which was test flown by Daunt on 12 January 1944. This Meteor was then sent to the US in exchange for a General Electric J31 (Power Jets W.1) powered Bell XP-59A Airacomet, RG362/G. The Meteor was first flown at Muroc Army Airfield by John Grierson on 15 April. Several test flights followed, and by December it had been shipped back to the UK. Production of the Meteor continued, with EF211 to 229 and 230 through 244 entering service No. 616 Squadron RAF in May 1944. The Wellands were rated at 1,600 lbf (7.1 kN), with 180 hours between overhauls. The Jumo 004B, which entering service only a few weeks earlier, was rated at 1,984 lbf (8.8 kN), but required overhaul after 10–20 hours. Flying from RAF Manston, near the English Channel, the 616 first saw action against the V-1 flying bombs en route to London on 27 July 1944.
From October 1943 a total of 167 Wellands were dispatched from the Rolls-Royce facility at Barnoldswick. By this point, Adrian Lombard's straight-through design, which became the Rolls-Royce Derwent, had proved to be both more reliable and somewhat more powerful, and production of the Welland ended.
The W.2B/700 was to be used in the Miles M.52 supersonic research aircraft. In order to achieve the thrust required for supersonic flight, a version of the engine was developed using a turbine-driven "augmenter" ducted fan (an early form of turbofan). The NO.4 augmenter was mounted behind the engine, drawing fresh air through ducts surrounding the engine. Power was boosted even further by supplying the air to the world's first "reheat jetpipe" or afterburner which was actually a very early athodyd or ramjet. The hope was that this combination of the W.2/700, turbofan augmenter and re-heat/ramjet would produce the required power for the proposed 1,000mph aircraft.