The Tumansky R-15 is an axial-flow, single-shaft

turbojet The turbojet is an airbreathing jet engine which is typically used in aircraft. It consists of a gas turbine with a propelling nozzle. The gas turbine has an air inlet which includes inlet guide vanes, a compressor, a combustion chamber, and ...

with an

afterburner An afterburner (or reheat in British English) is an additional combustion component used on some jet engines, mostly those on military supersonic aircraft. Its purpose is to increase thrust, usually for supersonic flight, takeoff, and combat ...

. Its best known use is on the

Mikoyan-Gurevich MiG-25 The Mikoyan-Gurevich MiG-25 (; NATO reporting name: Foxbat) is a Supersonic aircraft, supersonic Interceptor aircraft, interceptor and reconnaissance aircraft that is among the Flight airspeed record, fastest military aircraft to enter service ...

Design and development

The R-15-300 was designed at the OKB-300 design bureau led by

Sergei Tumansky Sergei Konstantinovich Tumansky (; – 9 September 1973) was a designer of Soviet aircraft engines and the chief designer in the Tumansky Design Bureau, OKB-300. He worked in TsIAM (1931–38 and in 1940), and at the aircraft-engine plant N 29, ...

in the late 1950s. The engine was originally intended for the Tupolev Tu-121 high-altitude high-speed

cruise missile A cruise missile is an unmanned self-propelled guided missile that sustains flight through aerodynamic lift for most of its flight path. Cruise missiles are designed to deliver a large payload over long distances with high precision. Modern cru ...

. Due to a lack of

Soviet The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

resources and funding, the engine casing was mainly

steel Steel is an alloy of iron and carbon that demonstrates improved mechanical properties compared to the pure form of iron. Due to steel's high Young's modulus, elastic modulus, Yield (engineering), yield strength, Fracture, fracture strength a ...

, and in areas exposed to high temperatures, 30-

micrometre The micrometre (English in the Commonwealth of Nations, Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a uni ...

silver Silver is a chemical element; it has Symbol (chemistry), symbol Ag () and atomic number 47. A soft, whitish-gray, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. ...

-plated steel. At the time, the

USSR The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

did not have the resources to exploit metals such as

titanium Titanium is a chemical element; it has symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in ...

or other alloys that could have reduced the weight of the engine. The Tu-121 was later canceled, but its basic design was used in the

Tupolev Tu-123 The Tupolev Tu-123 Yastreb (Hawk, ) was one of the earliest Soviet reconnaissance drones that began development in 1960. Sometimes referred to as the "DBR-1", it was introduced into active service in 1964. Design The Tu-123 was a long-range, ...

reconnaissance drone.

Performance

The maximum thrust was 7,500 kilograms force (73.5 kN, 16,500 lbf) dry and 11,200 kilograms force (110 kN, 24,700 lbf) with

. This thrust enabled the

, with two engines, to reach

Mach The Mach number (M or Ma), often only Mach, (; ) is a dimensionless quantity in fluid dynamics representing the ratio of flow velocity past a Boundary (thermodynamic), boundary to the local speed of sound. It is named after the Austrian physi ...

3.2, although the engines had to be scrapped after a flight to Mach 3.2. The engine had a very high fuel consumption, especially at low altitudes.

Variants

* R-15-300: Original version. Used in Tupolev Tu-123 Yastreb drone. * R-15-300M * R-15B-300: Electronic engine controls (the first for a Soviet engine). and modifications to increase life span. Original engine for the MiG-25P, MiG-25R and variants. * R-15BD-300: Improved and more powerful version for MiG-25PD and MiG-25PDS. Engine Lifespan increased up to 1000 Hours. * R-15BF2-300: Uprated version. Used in Ye-266M high-performance MiG-25M prototype. MiG-25M aircraft was never put into production

Applications

Mikoyan-Gurevich Ye-150 family The Mikoyan-Gurevich Ye-150 family was a series of prototype interceptor aircraft designed and built by the Mikoyan, Mikoyan-Gurevich design bureau in the Soviet Union from 1955. Design and development To fulfil the needs of the ''Protivo-Vozd ...

* Tupolev Tu-121 *

Specifications (R-15B-300)

References

External links

R-15 on LeteckeMotory.cz
(cs)

(ru) {{Russian and Soviet military designation sequences Tumansky aircraft engines 1950s turbojet engines