Kuznetsov NK-12 explained

The Kuznetsov NK-12 is a Soviet turboprop engine of the 1950s, designed by the Kuznetsov design bureau. The NK-12 drives two large four-bladed contra-rotating propellers, diameter (NK-12MA), and diameter (NK-12MV). It is the most powerful turboprop engine to enter service.

Design and development

The design that eventually became the NK-12 turboprop was developed after World War II by a team of Soviet scientists and deported German engineers under Ferdinand Brandner, who had worked for Junkers previously; the design bureau was headed by chief engineer Nikolai D. Kuznetsov. Thus, the NK-12 design evolved from late-war German turboprop studies. This started with the postwar development of the wartime Jumo 022 turboprop design that was designed to develop, weighing . The effort continued with a, weighing, completed by 1947. Evolution to the TV-12 engine required extensive use of new Soviet-developed alloys and was completed in 1951.

The NK-12 is the most powerful turboprop engine to enter service, ahead of the Europrop TP400 (in 2005). Another engine of similar size, the Pratt & Whitney T57 with and jet thrust, ran 3,100 hours before being cancelled in 1957.[1] [2] The NK-12 powers the Tupolev Tu-95 bomber and its derivatives such as the Tu-142 maritime patrol aircraft and the Tupolev Tu-114 airliner (with NK-12MV), which still holds the title of the world's fastest propeller-driven aircraft despite being retired from service in 1991. It also powered the Antonov An-22 Antei (with NK-12MA), the world's largest aircraft at the time, and several types of amphibious assault craft, such as the A-90 Orlyonok "Ekranoplan".

The engine has a 14-stage axial-flow compressor, producing pressure ratios between 9:1 and 13:1 depending on altitude, with variable inlet guide vanes and blow-off valves for engine operability. The combustion system used is a cannular-type: each flame tube is centrally mounted on a downstream injector that ends in an annular secondary region. The contra-rotating propellers and compressor are driven by the five-stage axial turbine. Mass flow is 65 kg (143 lb) per second.[3]

Variants

Data from Alexandrov

NK-12:, initial development model, used on the Tupolev Tu-95 and Tupolev Tu-116
  • NK-12M:, used on the Tupolev Tu-114
  • NK-12MV:,[4] AV-60 propellers, used on the Tupolev Tu-95, Tupolev Tu-126, and Tupolev Tu-142
  • NK-12MA:, AV-90 propellers, used on the Antonov An-22
  • NK-12MK:, propellers, built with corrosion-resistant materials, used on the A-90 Orlyonok
  • NK-12MP:,[5] modernized version used on the Tupolev Tu-95MS and Tupolev Tu-142M
  • NK-12MPM: Upgraded version of the NK-12MP that develops more power, produces half the vibration and is paired with the Aerosila AV-60T propeller; replaces the NK-12MP engine and AV-60K propeller on the Tupolev Tu-95MS[6]
  • Applications

    External links

    Notes and References

    1. Book: Connors . J. . The engines of Pratt & Whitney : a technical history . 2010 . American Institute of Aeronautics and Astronautics . 978-1-60086-711-8 . 294.
    2. Book: Mulready . Dick . Advanced engine development at Pratt & Whitney : the inside story of eight special projects, 1946-1971 . 2001 . Society of Automotive Engineers . 9780768006643 . 20.
    3. Web site: Creation of the TV-2 (NK-12) turboprop engine . www.airpages.ru . 22 March 2019.
    4. Encyclopedia: NK-12MV . Ulyanovsk Higher Aviation School of Civil Aviation . Russian . 18 . Domestic Aerospace Engineering . August 21, 2019.
    5. Encyclopedia: NK-12MP, NK-12MK . Ulyanovsk Higher Aviation School of Civil Aviation . Russian . 19 . Domestic Aerospace Engineering . August 21, 2019.
    6. News: . More power for the mighty 'Bear' . 31 October 2018 . Vladimir . Karnozov . Defense.