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