For more detailed images see the image gallery at the bottom of this post
The eighteen pot injector head.
This is the first image blog from Alexsander Savochkin in what we hope will become an expanding resource for those wishing to find out more about the design and construction of the A4/V2 missile. The precise 3D CAD model imagery is based exclusively on original drawings produced in Germany from 1940 to 1945. When enough material has been uploaded we will create a fixed menu item called ‘Anatomy of the V2‘ where we hope to be able to offer coverage of the entire missile in detailed 3D models like the ones shown here – Robert J. Dalby, editor in chief, V2 Rocket History.com
View of injector head showing liquid propellant (LOX and fuel) diffuser cups and head fuel valve seating ring at centre, (see other images for insert and position nomenclature). Visible immediately below the valve seat are the large connecting holes that allow fuel to flow from the inlet manifold and cooling jacket to the injector space (some brass injector inserts can be seen through the holes) after the head fuel valve is released to be opened by the turbo-pump supply pressure. The four veil cooling inlet connectors are well shown as are two of the outlet connection holes immediately above them. 3D model by Alexander SavochkinA close-up view of the head fuel valve mounting flange (showing 12 fastener holes). Visible immediately below the top flange are the large connecting holes that allow fuel to flow from the inlet manifold and cooling jacket to the injector space (some brass injector inserts can be seen through the holes) after the head fuel valve is released to be opened by the turbo-pump supply pressure.Inverted view of injector head showing liquid propellant (LOX and fuel) diffuser cups, (see other images for insert and position nomenclature). Of note in this image are the pointing angles of the cups, positioned on a parabolic section to focus the propellant nebular stream into the central axis of the combustion space. Also of note are the large areas between each cup NOT employed in the injection process leading to structured propellant mixing as opposed to even homogeneous mixing. The four veil cooling inlet connectors are well shown. 3D model by Alexander SavochkinUnderside view of injector head showing liquid propellant (LOX and fuel) diffuser cups, (see other images for insert and position nomenclature). Of note in this image are the pointing angles of the cups, positioned on a parabolic section to focus the propellant nebular stream into the central axis of the combustion space. Also of note are the large areas between each cup NOT employed in the injection process – initiating \’clumpy\’ and uneven propellant mixing initially below the injector face but also carried forward into the combustion space. The LOX spray head is shown in the centre of each cup. 3D model by Alexander SavochkinHere the 18-pot head model has been cut away to show the fuel cooling and fuel delivery spaces. the cooling jacket layer can be seen in the lowermost area of the head – below the centrally positioned fuel valve seat, between each cup at the lowest point, and running down toward the first set of veil cooling pores and the topmost coolant distributor ring. Note that the veil cooling system does not communicate with the regenerative cooling jacket and has its own feed pipes drawing fuel from the head injector space and not the cooling space. Visible immediately above the valve seat are the large connecting holes that allow fuel to flow from the inlet manifold and cooling jacket to the injector space after the head fuel valve is released to be opened by the turbo-pump supply pressure. 3D model by Alexander SavochkinClose-up detail showing independent pathway for fuel passing into injector head and fuel passed down from the head to be used for veil cooling system. Fig. A shows vertical passages for overall fuel feed to the head and Fig.B shows horizontal pathway for veil coolant fed from the head via the veil coolant distributor ring or manifold. 3D model by Alexander SavochkinLiquid propellant (LOX and fuel) diffuser cup, showing three rings or echelons (A, D,& E) of brass injector inserts as well as two rows of drilled fuel feed holes. The LOX spray head is shown in the centre. Note the simple ‘shower head or watering can’ design of the LOX diffuser. A sealing washer can be seen fitted between the LOX diffuser and the steel cup. 3D model by Alexander SavochkinView of the top of the injector head, with outer cups and pressed steel capping piece removed, showing, propellant diffuser inner cores with injector inserts and LOX supply pipe connection thread. The LOX spray head can be seen inside the LOX pipe connector. The swirl caps of fuel injector inserts in positions A, D,& E can be seen clearly on the outside of the cores and the two rows of drilled fuel feed holes are also well shown. 3D model by Alexander SavochkinGeneral view of the propellant diffuser cup inner core. The swirl caps of fuel injector inserts in positions A, D,& E can be seen clearly on the outside of the core as well as the central holes in the 3304D (red) inserts. The two rows of drilled fuel feed holes are also well shown. 3D model by Alexander Savochkin
Click the above video to see an animation of the diffuser cup inner core (the animation may take a few seconds to show at maximum resolution).
This image shows a burner cup from outer Ring I of the injector head and the cutaway shows injector insert echelon A, D, & E as well as two rows of drilled feed holes. Four fuel injector insert types can be seen: Top, A = 2131E, lower D, = 3303D (white), lowest E, = 3304D (red), and E, = 3305D (blue). 3D model by Alexander SavochkinCutaway showing echelon A with 2-part 2131E fuel injector inserts at the top of a propellant diffuser cup. Note the close proximity of the injector inserts to the simple ‘watering can’ type LOX spray head. One row of drilled fuel feed holes can be seen below the inserts. 3D model by Alexander SavochkinThis images shows a cutaway of a burner cup from outer Ring I of the injector head and shows injector insert echelon D, & E as well as one row of drilled feed holes. Three fuel injector insert types can be seen: Top D, = 3303D (white), lower E, = 3304D (red), and E, = 3305D (blue). 3D model by Alexander SavochkinOne of the 18 liquid propellants (LOX and fuel) diffuser cups, showing three rows or echelons (A, D,& E) of brass fuel injector inserts as well as two rows of drilled fuel feed holes. The LOX spray head is shown in the centre. 3D model by Alexander SavochkinExploded view showing some of the 1100 parts required for the complicated 18-pot injector head of the V2 25-ton thrust rocket engine. 3D model by Alexander Savochkin
The image gallery below has all the above pictures in higher resolution, some with additional text, as well as additional pictures not included in this post.
Drawing 5741 B1 - Fuel (B) Pump Spiral-housing
Drawing 5741 B1 - Fuel (B) Pump Spiral-housing
Drawing 5741 B1 mpe - Fuel (B) Pump Spiral-housing with dimensions. Drawing origin 18 July 1944, revised to new drawing (AM41780) 11 Jan 1945. (Digipeer.de image)
Drawing 5741 B - Fuel (B) Pump Assembly - Part Numbers
Drawing 5741 B - Fuel (B) Pump Assembly - Part Numbers
Drawing 5741 B mpe - Fuel (B) pump assembly showing part/drawing numbers. Drawing originates 20 July 1944 and revised with new number (AM41780) 16 Jan 1945. (Digipeer.de image)
Animation highlighting just one of many revisions to the turbo-pump that occurred at an accelerating rate between August 1943 and late 1944 as the missile moved from development to full production, and finally use in combat. (Digipeer.de images: animation RJD)
The injector head section of the 4B 1000kg thrust rocket engine is a precursor to the injector pot or 'pre-chamber' design used later for each of the 18-pots of the 25-ton V2 rocket engine. Most of the essential ingredients are shown in this drawing from 1940. Drawing no 1848E Deutsches Museum München online archive ref FA 014/12829
V2 Rocket standard screw-fit fuel Injector Insert 3304D 1944
V2 Rocket standard screw-fit fuel Injector Insert 3304D 1944
HAP11 drawing of standard 3304D fuel injector screw insert. showing details of primary swirl cavity and orrifice and all additional apertures including the four small cooling pores. HAP11 (Heimat-Artillerie-Park 11, AKA armament code: mpe), drawing number 4554D, Deutsches Museum München
HVP drawing no 1203D showing burner cup 'diffuser system' disposition for 19-pot head (at this stage the 25 ton thrust injector head had nineteen so called 'pre-chambers' or pots as no central fuel valve was present). HVP drawing dated 1939.
Drawing from the Army Experimental Station Peenemünde dated 1939. The specification describes an insert template that could be used for a range of outlet and inlet orifice sizes. The German text beginning (eingedrehte ...) translates as 'Center-line of screw used for holes to be drilled later', and the hole dimensions are not specified on this document. HVP drawing number 1113 E, Deutsches Museum München
Sectioned general assembly view of the V2 turbo-pump (TP) dated September 1942. This image has been edited to show TP and document data closer together than the original.
Fuel injector specifications for 25 Ton 18-pot engine
Fuel injector specifications for 25 Ton 18-pot engine
Specification for fuel injector inserts showing orifice size, type, and A to E echelon position. Peenemünde document dated 30th October 1943. Of note on this document is the combination of high and low volume injector inserts (3304D and 3305D) in the echelon E position of the 12 cups comprising outer ring I. It shows that each cup or pot on this outer ring had 16 inserts at the lowermost position E with 12 of the inserts with three inlet apertures (3305D) and 6 with only two inlet apertures (3304D being lower flow volume) positioned in the segment covering 165 degrees and closest to the outside edge of the head. HAP11 (Heimat-Artillerie-Park 11, AKA armament code: mpe), drawing number 4554D, Deutsches Museum München
A tutor in computer-aided design at Moscow State Technical University, Alexander Savochkin says he finds relaxation in transcribing 75-year-old missile plans into modern 3D CAD models. He lives with his very patient wife in the leafy suburbs of Moscow.
