Soviet Atomic Bombers - Atomoleta
In the postwar period, the world of winners was intoxicated with the discovered nuclear capabilities. And we are talking not only about the weapons potential, but also the peaceful use of the atom. In the US, for example, in addition to nuclear tanks, talk about the creation of even such household trivia as vacuum cleaners working on a nuclear chain reaction.
As early as 1942, one of the leaders of the American atomic bomb program Enrico Fermi discussed with other participants of this project the possibility of creating aircraft engines on nuclear fuel. Four years later, in 1946, the staff of the Laboratory of Applied Physics at the Johns Hopkins University devoted a special study to this problem. In May of the same year, the US Air Force Command approved the pilot project "Nuclear Energy for Aircraft", aimed at developing nuclear engines for strategic long-range bombers.
By the mid-1950s, a prototype of a small atomic reactor with air cooling was produced within its framework. It was important for the Air Force command to make sure that this reactor can be launched and muffled during the flight without posing a threat to the pilots. For flight tests, a giant 10-engine B-36H bomber was allocated, the carrying capacity of which was approaching forty tons. After re-equipment of the aircraft, the reactor was able to be placed in the bomb compartment and to protect the cockpit with a shield of lead and rubber. From July 1955 to March 1957, this machine made 47 flights, during which the reactor was periodically switched on and off in idle mode, in other words, without load. During these flights, no abnormal situations arose.
The first Russian strategic bombers had insufficient range. So, after a couple of years of design team running VM Myasishcheva managed to raise the 3M range aircraft to 11-11.5 thousand kilometers. In the application of in-flight refueling system this figure growing up. But strategic bombers since then have had a lot of problems. In light of the increasing range of the greater difficulty was to ensure the timely refueling at risk criteria attack enemy fighters. In the forthcoming due to the development of air defense worsened the problem of distance, also came in handy to begin designing supersonic aircraft strategic class.
By the end of the 50s, when they started looking at these issues, the opportunity to conduct research on other power plants. One of the main options have nuclear power plants. In addition to providing the highest range of flight, including the supersonic, they promised huge savings in financial terms.
The first documentary evidence of the existence of Russian programs for atomoletov refer to 1952, when the director of the Institute of Physics, Academy of Sciences of the USSR problems of the future academician AP Alexandrov sent IV Kurchatov document, which talked about the creation of a fundamentally capacity of nuclear power for aircraft. The next three years were spent on the slow side of the theoretical study of the issue.
From 1952 to 1955 in the USSR there had been discussions and studies, even including the construction of full-scale mockup of a nuclear-powered bomber. The mockup was based on studies by leading Soviet aircraft and missile designers Vladimir Myasishchev (the designer of the Bison bomber), Andrei Tupolev (credited with the Bull, Badger, and Bear bombers), Semyon Lavochkin (the designer of the Burya strategic cruise missile), and Sergei Korolev, who designed many missiles, including the first Soviet intercontinental ballistic missile (ICBM) and Sputnik, the first artificial Earth satellite to have been launched.
But ANP had not been a Soviet priority until 1955. Soviet intelligence determined that a US Air Force NB-36H (modified bomber) test flight in late December 1955 had been a successful test of radiation shielding of a nuclear reactor on board the bomber. The Soviets concluded that the flight was a step forward in a program to develop a nuclear-propelled bomber.
Exceptionally, in April 1955 the Council of Ministers of the USSR issued a decree according to which design offices AN Tupolev, SA Lavochkin and VM Myasishcheva had to start developing aircraft with a nuclear power plant, and design organizations, ND Kuznetsova and A.Ljulka were instructed to make engines for them. In this step, Russian programm to create aircraft with a nuclear power plant was divided into several projects, differing from each other by the type of the aircraft, the motor circuit, etc.
The Council of Ministers of the Soviet Union issued #1561-868s on August 12, 1955, in which it specifically ordered the start of the developments, including the Lavocskin robot machine. Additionally, the offices led by Tupoljev and Mjasischev (OKB-156 and -23) received the task of preparing aircraft, and the Kuznetsov and Ljulka offices (OKB-276 and -165) were responsible for their propulsion.
The Kuznetsov office design was "closed" - that is, when the reactor warms a fluid that is driven into the engine burner, but it only returns the heat and does not get into the environment. All this is suitable for a jet engine, see the Pratt & Whitney solution mentioned in the previous post, but the Russians were thinking of a propeller gas turbine at the base of the NK-12. Before the NK-14A, however, it is worth considering the plans on the other principle.
The Ljulka- led collective studied the "open" version, where the reactor warmed the surrounding air, flowing backward to provide direct thrust. Arhip M. Ljulka, the first Soviet gas turbine jet engineer, outlined three different arrangements. At the first, they were conservatively assigned to the task, and they were calculated to try to intervene as least as possible in the then very recent nuclear reactor technology. Therefore, after the compressor, the air was pushed sideways through a single channel so that the shaft of the gear unit did not need to be passed through the reactor. In the hollow duct, a small reactor with almost the same diameter as the normal diameter of the gearbox was introduced, ie virtually the "combustion chamber" ( detour arrangement). The hot air then returned to the shaft line and rotated the turbine, then left the gear, producing a thrust force. The second layout, meanwhile, with only a decade-long domestic jet engine technology, meant an average, only relatively large gear. Here the shaft passed through the reactor, and the latter was literally the site of the combustion chamber ( coaxial arrangement ).
The third, and final, layout took into account the expected conditions of application. The reactor was far from being as delicate as regular airplanes. Therefore, they thought that for a quick change of performance, the planned bomber will carry some conventional fuel, and this, using it flexibly, adjusts its performance with fine fineness. This, in turn, required either normal drives or dual "heat source" units. Although it was not impossible, it seemed more appropriate to develop a "mixed" solution ( hybrid layout). This contained a normal gas turbine unit in a common house, behind which the reactor was located, functioning as an aftercooler. This enabled the same unit to gain thrust by purely chemical combustion, or to increase it with nuclear heat. This was in line with the need for supersonic bombers.
The OKB-301 (SA Lavochkin chief designer) requested the creation of an intercontinental cruise missile "375." The basis for this weapon was supposed to be a rocket "Storm", also popular under the designation "350". After a series of investigations determined the kind of modern missiles "375." In practice, this was still the same, "The Tempest", but instead of the ram jet engine on kerosene on it proposed to establish a small nuclear reactor. Passing through the channels inside the rocket, outboard air had to come in contact with the reactor core and warm. It is at once protected the reactor from overheating and provides sufficient traction.
It was also planned to change the initial design of the assembly in the absence of the need for fuel in the tanks. Development of the missile itself was comparable to normal, but, as is often the case, subcontracting OKB-670 under the control of MM Bondaryuk long enough could not cope with the creation of a nuclear ramjet engine for the product "375." As a result, the newest cruise missile is not even built in the metal. Soon after the death of Lavochkin in 1960, the theme of "375" together with the unique "Storm" was closed. By this time the design of the nuclear engine moved off the ground, but to test the final standard as before was still far away.
From 1956 into 1961, the reinvigorated Soviet ANP program focused on development of an ANP testbed aircraft termed “Aircraft 119” or LAL (Letayushchaya atomnaya laboratoriya, the Flying Atomic Laboratory). It was affectionately called the Swallow (Lastochka). The Swallow was an adaptation of the largest Soviet bomber at the time, the four-engine turboprop Tu-95 (NATO code-name Bear). It was created in a large hangar at a nuclear complex near Semipalatinsk in Kazakhstan.
Extensive experimentation and analysis were undertaken in the laboratory, and multiple delays were experienced in working on the reactor. The Swallow finally took flight with a reactor on board (but not providing propulsion) in the summer of 1961. These flights, like the NB-36H flights in the United States, were successful, but it quickly became apparent that the problem of shielding the interior of the aircraft from the reactor’s radiation was too great.
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