Variants of the Soviet rocket engine Kuznetsov NK
(parameters and images)
 

The NK engines are the first Russian engines with a closed cycle. The second generation of these engines (NK-33, NK-43), intended for the N-1F, have been improved. They are also thrust adjustable and re-ignitable. This eliminates the gradual shutdown of engine groups as in the first generation for the N-1.
The working gas for the turbine is generated in the gas generator (better preburner) by burning with excess oxygen. The performance of the turbine and thus of the engine can be changed by varying the excess oxygen in the gas generator. In this way, a thrust between 100 and 50% of the nominal thrust can be achieved. However, this only applies to the second generation of these engines, which were intended for the N-1F.
All NK engines are potentially equipped with yaw, pitch and roll controls. Such regulations are carried out with exhaust nozzles via digital commands.
For this purpose, part of the working gas is used after passing through the turbine by feeding it into nozzles. However, only selected engines are actively used for this, two or more (?)  for each steering nozzle.
The part of the working gas that is branched off is fed into a small, separate pot with an exhaust pipe. From this pot, the control nozzles are supplied via valves by command. This pot includes an on and off mechanism. When the steerins are is finished, the valves are closed and the supplied exhaust gas escapes unused through the pipe. However, re-operation is possible. With engines that are not used for the control, an exhaust gas supply to the pot is permanently prevented.
Most of the working gas from the preburner is fed into the combustion chamber together with the fuel and serves to increase the pressure.

In July 1970, Kuznetsov received an order to develop significantly improved engines for the first and second stages of the N-1. However, it was to take another three years before these engines, designated NK-33 and NK-43, were available. They could at first time be used for the N-1F.
Finally five improved NK engines was developed by Kuznetsov:
The new NK-33 and NK-43 engines for the N-1F (upgraded versions of the NK-15 and NK-15V). The NK-31 and NK-39 engines (upgraded versions of the NK-21 and NK-19) and already available for the N-1 (6L and 7L). Two of the N-1F launcher (8L and 9L) had been fully assembled and readied on pad for flight. But in 1974 the program was cancelled. The two N-1F launcher were scrapped, the engines had previously been removed.
 

NK-9 type

Engine

NK-9

NK-9V

NK-19

NK-21

NK-31

NK-35 (LH2/LOX)

NK-39

NK-39K

Index

8D517

8D517V

11D53

11D59

11D 114

 ?

11D113

 ?

Use

GR-1 ICBM GR-1 / N-1 N-1 N-1 N-1 / N-1F UR-700 N-1 / N-1F Spaceplane

Stage

1 2 / 3,4, 5 (W,G,D) 3 (W) 4 (G) 4 (G)  ? 3 (W) 1

Thrust s.l. (t)

38

-

 -  -  - -  - 29.8

Thrust vac (t)

43.5

46

46

41

41 200 41.5  37.7

Isp s.l. (sec)

286.5

-

- - - - - 255.1

Isp vac (sec)

328

345

345 340 353 ? 352 322.7

Chamber pressure

? 10.34 MPa (?) ?  ? 9.20 MPa ? 9.20 MPa 9.20 MPa

Nozzle area ratio

 ? ? ? ? ?   114 ?

Flow rate (kg/sec)

132.6

133.3

133.3 120.1 116.1   117.9

 116.8

O/F mix

2.50 2.50 2.50 2.50 2.60   2.60

 2.60

Image

?


?






    similar NK-9V  

 

not realized   here without nozzle

NK-15 type

Engine

NK-15

NK-15V

NK-33

NK-33-1

NK-33M

 NK-33MN

NK-43

NK-43M

Index

11D51

11D52

11D111

 

 

 

11D112

 

Use

N-1 N-1 N-1F, Soyuz-1 Soyuz Yamal Polyot Air launch N-1F Polyot Air launch

Stage

1 (A) 2 (B) 1 (A)  1 1 1 2 (B) 1

Thrust s.l. (t)

140.6

-

 154  185 ~169.2 ~176.7  - -

Thrust vac (t)

     157.4

     168

 171.5  202.6 188 196 179.2 212

Isp s.l. (sec)

 284

-

 297.2  304.9 ~306 ~311 - -

Isp vac (sec)

      318

     325

331 333.9 ~340 ~345 346 349

Chamber pressure

 ?

?

14.53 MPa

17.16 MPa

? ? 14.57 MPa

17.16 MPa

Nozzle area ratio

    27.7 ~71.9     79.7 79.7

Flow rate (kg/sec)

 495.0

 516.9

 517.9

 606.8

 

   517.9

607.4

O/F mix

 2.50

 2.50

 2.60

2.60

2.60

2.60 2.80 2.80

Image





? ?
?
 source: alabin.ru source: alabin.ru  restartable modified NK-33 similar NK-33 similar NK-33  restartable  similar NK-43

 

Derivative

Engine

AJ-26-58

 AJ-26-59

AJ-26-60

AJ-26-62

Index

 (NK-33)

 (NK-33)

 (NK-43)

 (NK-33)

Use

Kistler K-1 Kistler K-1 Kistler K-1 Antares

Stage

1 1 2 1

Thrust s.l. (t)

 154.2  154.2  - 154.2 / 166.5

Thrust vac (t)

 171.9  171.9 180.4 171.4 / 185.1

Isp s.l. (sec)

 297.2  297.2 - 300.4

Isp vac (sec)

331.3 331.3 348.3 334

Chamber pressure

14.54 MPa 14.54 MPa 14.57 MPa 14.54 / 15.70 MPa

Nozzle area ratio

27.7 27.7 79.7 27.7

Flow rate (kg/sec)

 518.8  518.8  517.9  513.2 /554.2

O/F mix

 2.60  2.60  2.80  2.60

Image


?

 similar NK-33
restartable
 similar AJ-26-58
restartable
 similar NK-43
restartable
modified NK-33
throttle to 108% thrust

                

 

Exhaust steering nozzles of block-W