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.
V2 Turbopump: Full Assembly
V2 Turbopump: Full Assembly
Turbine powered propellant pumps for A4/V2 rocket engine - fuel pump on right. Full perspective assembly showing tubular ring steam inlet manifold with asbestos bandage extreme left, inlet flanges at top, frame support brackets, steam exhaust outlet square shape lower center. The overspeed trip switch can be seen just above center on fuel pump face plate. The fuel outlet flange can also been seen btm right of center. 3D model by Ray Matter
Turbine powered propellant pumps for A4/V2 rocket engine - fuel pump on right. Full assembly showing steam inlet manifold on left, inlet flanges at top, support brackets, steam exhaust outlet square shape lower center. The over-speed trip switch can be seen just above center on fuel pump face plate. The fuel outlet flange can also been seen btm right of center. 3D model by Ray Matter
Full assembly showing, from top, steam inlet ring manifold, LOX pump and portion of steam turbine assembly. View shows outlet flange facing camera. Note the three fine rings milled into flange face. The rings were designed to improve keying for the sealing 'putty' that was used to seal the connection between the flange face and the inlet pipe. 3D model Ray Matter
A (LOX) Pump close-up showing inlet flange, with fastener slots and holes, as well as the throat baffle. To the right and left of the flange, the steam inlets are shown - with steel cases covering the steam manifold connection flanges. Of special note in this view is the self-purge orifice seen at the top right-hand side of the inlet throat baffle. This hole allowed gas to escape from the top of the LOX volute space back to the low-pressure inlet throat and proved problematic in manufacturing and was revised in late 1944. 3D model Ray Matter
Close-up of turbine steam inlet ring manifold showing one of the entry points. The thin steel case that fits around the steam manifold mating flanges is clearly shown as is the wire restraint fastener locking system (see close-up in gallery). 3D model by Ray Matter
Turbine powered propellant pumps for A4/V2 rocket engine - close-up of turbine casing shows wire restraint fastener locking system. 3D model by Ray Matter
Close-up of turbine showing steel case with lid removed to show steam inlet ring manifold. The thin steel case that fits around the steam manifold mating flanges is clearly shown as is the wire restraint fastener locking system (see close-up in gallery). 3D model by Ray Matter
Close-up of turbine steam inlet ring manifold showing asbestos bandage wrapped around the tubular ring. Sometimes a thin wire was used to help retail the heat resistant material. This bandage is often missing from museum exhibits. 3D model by Ray Matter
B (fuel) Pump sub-assembly, single piece casting showing machined (milled) areas without fittings. View shows inlet flange fastener slots and the throat aperture - facing right, initially blanked off by square plate, but towards the end of 1944 used for fuel return from the main fuel valve situated in the center of the thrust chamber injection head. 3D model Ray Matter
B (fuel) Pump sub-assembly shown without fittings. Single piece casting showing detail of bearing and seal cavity as well as threaded fuel bleed connection. 3D model Ray Matter
B-Pump sub-assembly, showing earlier version square inlet throat blanking plate (later versions employed a fuel return connection point mounted on this plate). Fastenings, turbine case contact furniture, splined turbine connection shaft, and shaft seal cap are also shown. 3D model Ray Matter
B-Pump sub-assembly complete with fastenings, turbine case contact furniture, splined turbine connection shaft, and shaft seal cap. 3D model Ray Matter
B-Pump Sub-assembly shown from top. View shows outlet flange facing camera - the splined drive shaft can just be seen at the top of the screen. Note the three fine rings milled into flange face.The rings were designed to improve keying for the 'putty' that was used to seal the connection between the flange face and the inlet pipe. Note, small self-purge orifice on the lower left of the inlet throat baffle. Unlike the upper purge hole in the LOX casing, the shallower face angle at the location of the hole in the fuel pump casing, was more accessible to drilling and was therefore not problematic. 3D model Ray Matter
B-Pump sub-assembly close-up showing fuel outlet flange. Note the three fine rings milled into the flange face. The rings were designed to improve keying for the 'putty' that was used to seal the connection between the flange face and the flow choke. Both faces of the choke and top face of the fuel outflow connector had similar rings. 3D model Ray Matter
B Pump housing sectioned to show baffle with vent and volute space area expansion as flow passes from inlet (left) to outlet (right). 3D model Ray Matter
'B' fuel pump housing for V2 rocket engine turbopump showing cast and machined surfaces - some machined areas with obvious specular reflections. Of note are the rarely seen machined contact points on the integral support brackets and the larger areas in two locations in the ring of double ended bolt fixing holes seen at 12 and 6 o'clock. These areas allowed two 'push' screws to be threaded into corresponding locations in the face plate. These could then be screwed down to provide a pushing force to remove the face plate from the main housing seat. This retraction system was required owing to the very tight fit of the face plate due to the narrow 'piston fit' tolerances and the vacuum effect of a soft gasket that was employed between the faces. 3D model by Ray Matter
Close-up of 'B' fuel pump housing displaying cast and machined surfaces. Fuel inlet aperture shown with small purge orifice shown at 2 o'clock. 3D model by Ray Matter
B Pump Housing, sectioned to show close-up of fuel bleed aperture and baffle vent for fuel pressure equalization between cavities inside the B pump casing. 3D model by Ray Matter
B (fuel) pump sub-assembly elevation view showing sectioned casing to reveal centrifugal pump impeller (in light purple for visibility). Outlet to left. The centrifugal pump impeller has been sectioned to remove one impeller face and reveal the curved vanes. The hub pass holes and end view of splined shaft are also shown. The spiral volute shape is very clear in this image. 3D model Ray Matter
B (fuel) pump sub-assembly showing sectioned casing to reveal centrifugal pump impeller (in light purple for visibility). Outlet to top right. The centrifugal pump rotor has been sectioned to remove one impeller face and reveal the curved vanes.The shaft and spiral volute space shape is very clear in this image. 3D model Ray Matter
B (fuel) pump sub-assembly showing sectioned casing to reveal centrifugal pump impeller. Outlet to btm right. The centrifugal pump impeller has been sectioned to remove one rotor face and reveal the curved vanes. The shaft and spiral volute space shape are shown in this image. 3D model Ray Matter
Turbine powered propellant pumps for A4/V2 rocket engine. The assembly is shown quarter sectioned and inverted with the propellant outlet flanges to the top and fuel pump on left, with inlet flanges at btm. The overspeed trip switch can be seen just below center on fuel pump face plate - the copper alloy centrifugal trip rotor is clearly visible in the trip-switch housing. 3D model by Ray Matter
A-Pump LOX sub-assembly complete with face plate and fastenings as well as outlet throat plug. Shows square inlet throat blanking plate. 3D model Ray Matter
A (LOX) Pump sub-assembly, showing the face nearest the steam turbine. Turbine side of LOX pump showing flexible shaft connection disk (back component with 12 holes). The connection cavity drain pipe is shown (running across the outflow to the btm right). 3D model Ray Matter
A (LOX) pump housing cutaway to reveal pump rotor side. The casing has been cut to show the internal rotor space detail. The outlet throat, right, and spiral volute space are displayed in this view as is the central LOX inlet. The web with the self-purge passageway can be seen on the outside center of the inlet throat, and connecting to the volute casing. The web or buttress seen to the upper right is to provide additional support between the structures whilst keeping the casting to an even density. 3D model Ray Matter
Close-up of 'A' LOX pump housing displaying cast and machined surfaces. LOX inlet aperture shown wand external threaded hole for manual bleed plug shown on far right. 3D model by Ray Matter
A (LOX) Pump sub-assembly, showing the face nearest the steam turbine. Single piece casting showing machined (milled) areas and detail of bearing and seal cavity. The four turbine case fitting brackets are displayed. 3D model Ray Matter
A (LOX) Pump housing sectioned to show baffle and volute space area expansion as flow passes from inlet (right) to outlet (left). Note cast and machined (milled) areas shown in this image - especially inlet aperture. 3D model Ray Matter
A (LOX) Pump housing sectioned to show baffle and volute space area expansion as flow passes from inlet (right) to outlet (left). Note the small LOX passageways on left from high-pressure volute space to bearing cavity. 3D model Ray Matter
Detail of fuel pump face plate showing over-speed switch and mounting. The switch plunger (part with disc shaped hand knob on left) is shown in the out or armed position. The RPM of the tubo-pump (TP) was not governed but this safety mechanism shut the TP down permanently when the RPM reached 5000. Although rarely changed, thin shims could be used to reduce or increase this speed. 3D model Ray Matter
Detail of fuel pump face plate showing over-speed switch and mounting. The eccentric centrifugal rotor can be seen (brass coloured part). This unbalanced part rotates against a spring load that allows the thicker (proportionally heavier) section of the rotor to move outwards from the center as the rotational speed rises and push the release rod clear of a keyed section of the plunger shaft (part with disc shaped knob on left) thus operating a relay switch that shuts down the flow of steam to the turbine. 3D model Ray Matter
V2 turbo-pump turbine and pump impeller shaft assembly
V2 turbo-pump turbine and pump impeller shaft assembly
V2 turbo-pump turbine and pump impeller shaft assembly showing steam turbine rotor with nozzle assembly and steam inlet manifold distributor ring. The two rows of steam buckets can seen on rotor rim. Fuel pump impeller (purple) and over-speed switch are shown to the right. LOX pump impeller (purple) with journal bearing box and four sectional bronze bearings visible. An overboard dump pipe can be seen lower left of steam rotor. 3D model Ray Matter
02 V2 turbo-pump turbine and pump rotor shaft assembly
02 V2 turbo-pump turbine and pump rotor shaft assembly
V2 turbo-pump turbine and pump impeller shaft assembly showing steam turbine rotor with nozzle assembly and steam inlet manifold distributor ring to left. The two rows of steam buckets can seen on rotor rim as well as three of the four sets of stationary steam return blades. Fuel pump impeller and over-speed switch are shown to the right. 3D model Ray Matter
B (fuel) Pump: Close-up of sectioned turbine and pump impellers. Pump impeller (purple) and turbine rotor, top left, showing, seals, bearings and over-speed centrifugal rotor assembly. 3D model Ray Matte
06 B Pump showing shaft area from fuel pump impeller, left (purple), to steam rotor. Shows seals, packer, circlip, and steam rotor hub. 3D model Ray Matter
B (fuel) Pump: Close-up of sectioned pump impeller hub (purple) showing, left to right, seals, bearing and over-speed centrifugal rotor. 3D model Ray Matter
B (fuel) pump sub-assembly showing sectioned casing to reveal centrifugal pump impeller (in light purple for visibility). Outlet to right. Note inlet throat purge aperture of left. 3D model Ray Matter
B pump casing removed to show fuel pump impeller and bearing ring. The steam rotor assembly can be seen at the top of the image and two sets of the stationary steam blades, or stators, are also visible.
B pump housing from pump rotor side - notional surface polish to show shape and detail (such a surface was not used on the actual pump parts). The casing has been cut to show the internal rotor space detail. The outlet throat, right, and spiral volute space are displayed in this view as is the central fuel inlet. 3D model Ray Matter
B pump housing - sectioned - showing self-purge orifice
B pump housing - sectioned - showing self-purge orifice
B pump housing with notional surface polish to show shape and detail (such a surface was not used on the actual pump casing). The casing nearest the turbine has been cutaway to reveal internal detail. The small self-purge orifice can be seen in this view, lower middle to the right of separator. 3D model Ray Matter
B pump housing with notional surface polish to show shape and detail (such a surface was not used on the actual pump casing). The casing nearest turbine has been cut to show internal detail. Inlet flange and split throat detail are clear in this view.
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.
