The Tumansky R-15 is an axial-flow, single-shaft turbojet with an afterburner. Its best known use is on the Mikoyan-Gurevich MiG-25.

Design and development

The R-15-300 was designed at the OKB-300 design bureau led by Sergei Tumansky in the late 1950s. The engine was originally intended for the Tupolev Tu-121 high-altitude high-speed cruise missile. Due to a lack of Soviet resources and funding, the engine casing was mainly steel, and in areas exposed to high temperatures, 30-micrometre silver-plated steel. At the time, the USSR did not have the resources to exploit metals such as titanium 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 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 afterburner. This thrust enabled the Mikoyan-Gurevich MiG-25, with two engines, to reach Mach 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

Applications

Specifications (R-15B-300)