Kuznetsov NK-12


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, and diameter. 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 Russian 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 remains the most powerful turboprop engine to enter service, although the Europrop TP400 has come close to this. Another engine of similar size, the Pratt & Whitney T57 with and jet thrust, ran 3,100 hours before being cancelled in 1957. 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, 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, 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 per second.

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:, 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:,, modernized version used on the Tupolev Tu-95MS and Tupolev Tu-142M

Applications