Tumansky R-25

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Tumansky R-25 is a turbojet engine, which is seen as the ultimate development of Tumansky R-11. It was designed under the leadership of Sergei Alekseevich Gavrilov.

[edit] Background

The Tumansky R-25 was designed as a replacement for Tumansky R-13 in MiG-21 fighters. R-25 is a two-spool axial-flow turbojet featuring a new compressor with increased overall pressure ratio and airflow, variable afterburner, and greater use of titanium. The engine was used on MiG-21bis and Sukhoi Su-15bis. A total of 3,200 R-25 were built between 1971 and 1975. The engine was also built under license by HAL in India for their fleet of MiG-21bis.

[edit] Specifications (R-25-300)

General characteristics

• Type: Afterburning turbojet
• Length: 4,615 mm (181.7 in)
• Diameter: 1,191 mm (46.9 in)
• Dry weight: 1,212 kg (2,670 lb)

Components

• Compressor: Two-spool axial compressor

Performance

• Thrust:
  
  • 40.3 kN (9,060 lbf) military power
  • 68.5 kN (15,400 lbf) with afterburner
• Overall pressure ratio: 9.5:1
• Turbine inlet temperature: 1,040 °C (1,904 °F)
• Specific fuel consumption:
  
  • 93 kg/(h·kN) (0.91 lb/(h·lbf)) at idle
  • 98 kg/(h·kN) (0.96 lb/(h·lbf)) at maximum military power
  • 229 kg/(h·kN) (2.25 lb/(h·lbf)) with afterburner
• Thrust-to-weight ratio: 56.5 N/kg (5.8:1)