Pv elite 2016 system requirements free. Download Codeware COMPRESS for Windows XP
Looking for:
Intergraph PV Elite SP1 Free Download - Rahim soft |
- Download Codeware COMPRESS for Windows XP - Get Into PC
Pv elite 2016 system requirements free -
The Rolls-Royce Merlin is a British liquid-cooled V piston aero engine of litres 1, cu in capacity. Rolls-Royce designed the engine and first ran it in as a private venture. Initially known as the PV , it was later called Merlin following the company convention of naming its four-stroke piston aero engines after birds of prey. After several modifications, the first production variants of the PV were completed in The Merlin remains most closely associated with the Spitfire and Hurricane, although the majority of the production run was for the four-engined Avro Lancaster heavy bomber.
A series of rapidly-applied developments, brought about by wartime needs, markedly improved the engine's performance and durability. Starting at 1, hp for the first production models, most late war versions produced just under 1, hp, and the very latest version as used in the de Havilland Hornet over 2, hp.
Post-war, the Merlin was largely superseded by the Rolls-Royce Griffon for military use, with most Merlin variants being designed and built for airliners and military transport aircraft. Production ceased in after a total of almost , engines had been delivered. Merlin engines remain in Royal Air Force service today with the Battle of Britain Memorial Flight , and power many restored aircraft in private ownership worldwide.
In the early s, Rolls-Royce started planning its future aero-engine development programme and realised there was a need for an engine larger than their litre 1, cu in Kestrel which was being used with great success in a number of s aircraft.
This proved unreliable and when ethylene glycol from the U. The Hart was subsequently delivered to Rolls-Royce where, as a Merlin testbed , it completed over hours of flying with the Merlin C and E engines.
Production contracts for both aircraft were placed in , and development of the PV was given top priority as well as government funding. Following the company convention of naming its piston aero engines after birds of prey, Rolls-Royce named the engine the Merlin after a small, Northern Hemisphere falcon Falco columbarius. Two more Rolls-Royce engines developed just prior to the war were added to the company's range.
The hp kW Rolls-Royce Peregrine was an updated, supercharged development of their V Kestrel design, while the 1, hp 1, kW litre 2, cu in Rolls-Royce Vulture used four Kestrel-sized cylinder blocks fitted to a single crankcase and driving a common crankshaft, forming an X layout. Although the Peregrine appeared to be a satisfactory design, it was never allowed to mature since Rolls-Royce's priority was refining the Merlin.
As a result, the Peregrine saw use in only two aircraft: the Westland Whirlwind fighter and one of the Gloster F. The Vulture was fitted to the Avro Manchester bomber, but proved unreliable in service and the planned fighter using it — the Hawker Tornado — was cancelled as a result. Initially the new engine was plagued with problems such as failure of the accessory gear trains and coolant jackets.
Several different construction methods were tried before the basic design of the Merlin was set. The Merlin III was the first version to incorporate a "universal" propeller shaft, allowing either de Havilland or Rotol manufactured propellers to be used. The first major version to incorporate changes brought about through experience in operational service was the XX, which was designed to run on octane fuel. The Merlin XX also utilised the two-speed superchargers designed by Rolls-Royce, resulting in increased power at higher altitudes than previous versions.
This substantially improved engine life and reliability, removed the fire hazard of the flammable ethylene glycol , and reduced the oil leaks that had been a problem with the early Merlin I, II and III series. The process of improvement continued, with later versions running on higher octane ratings, delivering more power. Fundamental design changes were also made to all key components, again increasing the engine's life and reliability. SM the high altitude version of the Merlin Series achieved 2, horsepower 1, kW at 36 lb boost "Hg on octane fuel with water injection.
With the end of the war, work on improving Merlin power output was halted and the development effort was concentrated on civil derivatives of the Merlin. This "cross-over" system took the exhaust flow from the inboard bank of cylinders up-and-over the engine before discharging the exhaust stream on the outboard side of the UPP nacelle.
As a result, sound levels were reduced by between 5 and 8 decibels. The modified exhaust also conferred an increase in horsepower over the unmodified system of 38 hp 28 kW , resulting in a 5 knot improvement in true air speed. Still-air range of the aircraft was also improved by around 4 per cent. Power ratings for the civil Merlin , , and series was 1, hp kW continuous cruising at 23, feet 7, m , and 1, hp 1, kW for take-off.
Merlins — were rated at 1, hp 1, kW continuous cruising at 18, feet 5, m , and 1, hp 1, kW for take-off. From Jane's : [29]. Most of the Merlin's technical improvements resulted from more efficient superchargers , designed by Stanley Hooker , and the introduction of aviation fuel with increased octane ratings. Numerous detail changes were made internally and externally to the engine to withstand increased power ratings and to incorporate advances in engineering practices. In September the Spitfire prototype, K , was fitted with ejector type exhausts.
Later marks of the Spitfire used a variation of this exhaust system fitted with forward-facing intake ducts to distribute hot air out to the wing-mounted guns to prevent freezing and stoppages at high altitudes , replacing an earlier system that used heated air from the engine coolant radiator. The latter system had become ineffective due to improvements to the Merlin itself which allowed higher operating altitudes where air temperatures are lower. Central to the success of the Merlin was the supercharger.
Lovesey , an engineer who was a key figure in the design of the Merlin, delivered a lecture on the development of the Merlin in ; in this extract he explained the importance of the supercharger:.
The impression still prevails that the static capacity known as the swept volume is the basis of comparison of the possible power output for different types of engine, but this is not the case because the output of the engine depends solely on the mass of air it can be made to consume efficiently, and in this respect the supercharger plays the most important role During the course of research and development on superchargers it became apparent to us that any further increase in the altitude performance of the Merlin engine necessitated the employment of a two-stage supercharger.
As the Merlin evolved so too did the supercharger; the latter fitting into three broad categories: [34]. The Merlin supercharger was originally designed to allow the engine to generate maximum power at an altitude of about 16, ft 4, m. In Stanley Hooker, an Oxford graduate in applied mathematics, explained " I soon became very familiar with the construction of the Merlin supercharger and carburettor Since the supercharger was at the rear of the engine it had come in for pretty severe design treatment, and the air intake duct to the impeller looked very squashed These modifications led to the development of the single-stage Merlin XX and 45 series.
A significant advance in supercharger design was the incorporation in of a two-speed drive designed by the French company Farman to the impeller of the Merlin X.
In , after receiving a request in March of that year from the Ministry of Aircraft Production for a high-rated 40, ft 12, m Merlin for use as an alternative engine to the turbocharged Hercules VIII used in the prototype high-altitude Vickers Wellington V bomber, Rolls-Royce started experiments on the design of a two-stage supercharger and an engine fitted with this was bench-tested in April , eventually becoming the Merlin The two-stage Merlin family was extended in with the Merlin 66 which had its supercharger geared for increased power ratings at low altitudes, and the Merlin 70 series that were designed to deliver increased power at high altitudes.
While the design of the two-stage supercharger forged ahead, Rolls-Royce also continued to develop the single-stage supercharger, resulting in in the development of a smaller "cropped" impeller for the Merlin 45M and 55M; both of these engines developed greater power at low altitudes.
V variant of the Spitfire fitted with these engines became known as the "clipped, clapped, and cropped Spitty" to indicate the shortened wingspan , the less-than-perfect condition of the used airframes , and the cropped supercharger impeller.
By comparison, the contemporary Bf E , which had direct fuel injection , could "bunt" straight into a high-power dive to escape attack. RAF fighter pilots soon learned to avoid this with a "half-roll" of their aircraft before diving in pursuit.
Another improvement was made by moving the fuel outlet from the bottom of the S. Further improvements were introduced throughout the Merlin range: saw the introduction of a Bendix-Stromberg pressure carburettor that injected fuel at 5 pounds per square inch 34 kPa ; 0.
The final development, which was fitted to the series Merlins, was an S. The Merlin R. From late , octane fuel became available from the U. At this power setting these engines were able to produce 1, horsepower kW at 9, ft 2, m while running at 3, revolutions per minute. Better results were achieved by adding 2. IXs to intercept V-1 flying bombs coming in at low altitudes.
Production of the Rolls-Royce Merlin was driven by the forethought and determination of Ernest Hives , who at times was enraged by the apparent complacency and lack of urgency encountered in his frequent correspondence with the Air Ministry , the Ministry of Aircraft Production and local authority officials.
All the Merlin-engined aircraft taking part in the Battle of Britain had their engines assembled in the Derby factory. Total Merlin production at Derby was 32, To meet the increasing demand for Merlin engines, Rolls-Royce started building work on a new factory at Crewe in May , with engines leaving the factory in The Crewe factory had convenient road and rail links to their existing facilities at Derby. Production at Crewe was originally planned to use unskilled labour and sub-contractors with which Hives felt there would be no particular difficulty, but the number of required sub-contracted parts such as crankshafts, camshafts and cylinder liners eventually fell short and the factory was expanded to manufacture these parts "in house".
Initially the local authority promised to build 1, new houses to accommodate the workforce by the end of , but by February it had only awarded a contract for Hives was incensed by this complacency and threatened to move the whole operation, but timely intervention by the Air Ministry improved the situation. In a strike took place when women replaced men on capstan lathes , the workers' union insisting this was a skilled labour job; however, the men returned to work after 10 days.
Total Merlin production at Crewe was 26, The factory was used postwar for the production of Rolls-Royce and Bentley motor cars and military fighting vehicle power plants. In Volkswagen AG bought the Bentley marque and the factory. Today it is known as Bentley Crewe. Hives further recommended that a factory be built near Glasgow to take advantage of the abundant local work force and the supply of steel and forgings from Scottish manufacturers. The factory was fully occupied by September A housing crisis also occurred at Glasgow where Hives again asked the Air Ministry to step in.
With 16, employees, the Glasgow factory was one of the largest industrial operations in Scotland. Unlike the Derby and Crewe plants which relied significantly on external subcontractors , it produced almost all the Merlin's components itself. Worker absenteeism became a problem after some months due to the physical and mental effects of wartime conditions such as the frequent occupation of air-raid shelters.
It was agreed to cut the punishing working hours slightly to 82 hours a week, with one half-Sunday per month awarded as holiday. Immediately after the war the site repaired and overhauled Merlin and Griffon engines, and continued to manufacture spare parts. The Ford Motor Company was asked to produce Merlins at Trafford Park , Stretford , near Manchester , and building work on a new factory was started in May on a acre 48 ha site.
Built with two distinct sections to minimise potential bomb damage, it was completed in May and bombed in the same month. Despite this, the first Merlin engine came off the production line one month later and it was building the engine at a rate of per week by , [88] at which point the joint factories were producing 18, Merlins per year.
Some 17, people worked at the Trafford Park plant, including 7, women and two resident doctors and nurses. Total Merlin production at Trafford Park was 30, As the Merlin was considered to be so important to the war effort, negotiations were started to establish an alternative production line outside the UK.
Rolls-Royce staff visited North American automobile manufacturers to select one to build the Merlin in the U. Henry Ford rescinded an initial offer to build the engine in the U. Six development engines were also made by Continental Motors, Inc. This is a list of representative Merlin variants, describing some of the mechanical changes made during development of the Merlin.
Engines of the same power output were typically assigned different model numbers based on supercharger or propeller gear ratios, differences in cooling system or carburettors, engine block construction, or arrangement of engine controls.
Comments
Post a Comment