Kuznetsov NK-12

The Kuznetsov NK-12 is a Soviet turboprop engine of the 1950s, designed by the Kuznetsov design bureau. It drives huge eight-bladed (four per propeller) contra-rotating propellers 5.6 m in diameter (6.2 m in the NK-12MA) and weighing 1,155kg (NK-12MV).

The NK 12 turboprop was originally developed after World War II by a German ex-Junkers team under Ferdinand Brandner, evolving from late war German turboprop studies . This started with the post-war development of the wartime Jumo 012 turboprop design that developed 6000 ehp in a 3000 kg engine. The effort continued with a 5000 ehp engine that weighed in at 1700 kg, completed by 1947. The evolution to the TV-12 12000 Ehp engine required extensive use of new Soviet-developed alloys and was completed in 1951.

The NK-12M developed 8,948 kW (12,000 ehp) uprated in the NK-12MV to 11,033 kW (14,795 ehp) and reaching 11,185 kW (15,000 ehp) in the NK-12MA. NK-12 is by a wide margin the most powerful turboprop engine ever built, only recently the Progress D-27 and Europrop TP400 come somewhat close. It powered the Tupolev Tu-95 / Tu-142 bomber, the Tupolev Tu-114 airliner NK-12MV (still the world's fastest propeller-driven aircraft), and the Antonov An-22 Antheus NK-12MA — the world's largest aircraft at the time. It has also been used to power several types of amphibious assault craft, such as the A-90 Orlyonok "Ekranoplan".

The contra-rotating propellers are driven by a 14-stage axial-flow compressor producing compression ratios between 9:1 to 13:1 according to altitude, controlled also by variable inlet guide vanes and blow-off valves. The combustion system used is a cannular-type: each flame tube is centrally mounted on a down-stream injector that ends in an annular secondary region. The single turbine is a five-stage axial. Mass flow is 65 kg (143 lb) /sec.

External links

• ciad.ssau.ru - image