3D CAD model images of the A4/V2 rocket engine's steam turbine powered propellent pumps - all images by Ray Matter. To see Ray Matter's blog 3D CAD modelling the V2 rocket turbopump introducing these images, just click the link.
Each burner cup of the V2 rocket engine injector system has forty-four brass inserts, but each cup also has twenty-four 2mm diameter plain holes, 30 deg apart, drilled into the cup's central wall. To mimic this for testing purposes, we created a brass insert that has a base with just a 2mm central hole. The base is sized to be consistent with the 4 to 5mm cup wall. V2RH image
V2 rocket engine fuel injector inserts - a part of our collection used for the water tests with various types shown. The tool shown is a pin-wrench used to fit the inserts into the test apparatus. V2RH collection image
3305D fuel injector insert showing swirl cone nebular, and 4 steady steams emanating from cooling pores.
3305D fuel njector insert showing comparison nebular and jet stream pattern with high and low pressure. Left image shows correct hollow cone-shaped aerosol effect from central 6mm orifice, that is also creating a fine mist around and within the cone, and 4 steady steams emanating from cooling pores. Right image shows the effect of reduced pressure: a dropping poorly formed cone, composed of larger slower moving droplets, and a tendency for the thicker spray to combine and cause 'dribbeling' with much fluid failing to clear the injector face.
3304D higher volume fuel injector insert (with three inlet apertures: 2 swirl, 1 jet) showing swirl cone nebular, steady central jet, and 4 steady steams emanating from cooling pores.
3305D injector insert showing larger low-velocity droplets and 'dribbly' performance due to insufficient pressure. The cone shaped aerosol is not functioning. Broken streams can be seem emanating from the four cooling pores.
3305D injector insert showing comparison nebular and jet stream pattern with high and low pressure. Top image shows correct hollow cone-shaped aerosol effect, from central 6mm orifice, that is also creating a fine mist around and within the cone, and steady steams emanating from cooling pores. Bottom image shows the effect of reduced pressure: a dropping poorly formed cone, composed of larger slower moving droplets, and a tendency for the thicker spray to combine and cause 'dribbeling' with much fluid failing to clear the injector face - unlike the image above, where the injector face is clear of drips.
Image shows a correctly formed nebular cone attended by a fine mist. the four injector cooling jets are well shown, and although fluid beading can be seen on the face of the injector, there is insufficient liquid to cause dripping.
Single fuel injector water test rig showing a 3305D bress insert about to be tightened home using a pin-wrench. V2RH image
3304D higher volume injector insert (with central jet) showing comparison nebular and jet stream pattern with high and low pressure. Top image shows correct hollow cone-shaped aerosol effect from central 6mm orifice, that is also creating a fine mist around and within the cone, and strong single central (non-swirl) jet can be seen as well as 4 steady steams emanating from cooling pores. Bottom image shows the effect of reduced pressure: a dropping poorly formed cone, composed of larger slower moving droplets, and a tendency for the thicker spray to combine and cause 'dribbeling' with much fluid failing to clear the injector face. The appearance of central jet however seem largely unchanged.
Parts of the 'Standard' series A aluminium head from 1941. The brass injector insert type and position pattern on the relics seem to be of the standard type but the pattern is non-standard in that higher volume injectors with three inlet apertures (two centrifugal and one central) have been place nearest the LOX
injector. Photo courtesy Horst Beck
Industrial magazine advert for Gustav Schlick printed in 1918 and showing graphic of steam boiler jets. The company, formed in 1902, had a wide expertise in all aspects of industrial spray technology and were able to steer the direction of fuel injector development along fruitful lines after they became consulting contractors to Dr Walter Thiel's combustion research group in 1937.
Sample set of 3303D type fuel injector inserts that were found in Peenemünde in part of a group that were bunched together in a space about 300mm in diameter with the remains of packaging. They appear to be manufacturing samples and and some have been graded with numbers 1,2,3, as well as with red and white paint to show the burner cup echelon position (C or D). Five different manufacturers are represented in this group. V2RH collection image
The injector head fragment shown here, is from an 4B 1000 kg thrust engine that was developed at Kummersdorf in 1938/39 by Dr Walter Thiel's combustion research group. The fragment, clearly the remains of an explosion, was actually found in a scrap pile in Peenemüde but the engine was probably tested (and destroyed) at the Kummersdorf army testing station. V2RH collection image.
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
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
Photo shows a small section of the burner cup with row A (2131E) fuel injector inserts with three row B drilled holes below. The two undamaged inserts carry the armament code 'csl'. The relic was found near a workshop in the Development works Pennemünde. Slag from the cutting flame and damage to the inserts at both ends of the relic would indicate that the section was cut from a steel burner cup using a gas cutter (fuel and oxygen) for purposes unknown. V2RH collection image
Diagram showing cut-away presentations of the settled configuration of standard four 'swirl' inserts used in the V2 rocket engine's 18-pot head from 1943 until the end of the war. The inserts are shown with their drawing code identification. All of the insert types used in the injector head are shown, however there were additional screw-in type fuel supply inserts, used to provide a fuel cooling balance function, located radially in the lower part of the combustion cavity.
V2 Fuel Injector insert: part code 2131E from injector pot echelon A (nearest to LOX spray head). The push-together two part construction of the insert is shown here. The two parts were pushed together in a specially shaped tool set that compressed the thin skirt on the female part into a recess cut into the male part. The failure test for this component required that the mated parts resist a separating force of 300kg. The two part design was dictated by the small size of the 2mm exit orifice and the funnel shaped introduction to the exit orifice. In the case of the other three standard inserts, the large 6mm exit orifice allowed a sub 6mm milling cutter, with a thin support shaft and a top chamfer, to be used in such a way that the area below the exit orifice could be undercut to create an injector cavity with a diameter larger than the 6mm entry point.
Single nozzle insert test rig used by V2 Rocket History to test spray shape and volume at fluid supply pressures consistent with fuel pressures specified for the injector head of summer 1944. A 2131E fuel injector insert is installed in the holder at the front of the test rig, but as the thread was the same on all inserts the nozzle can be changed for other models easily with aid of a pin spanner. See video for a demonstration of this simple test system.
V2 fuel injector inserts 3303D, 3304D, and 3305D for injector pot echelons D and E. Photo shows swirl inlet aperture size and position.The total number of each insert type is shown, each of the 18 pots carried a total of 44 inserts. An additional 24 feed holes were drilled into the burner cup, occupying two rows B and C having 12 holes each. V2RH image
Single nozzle insert test rig used by V2 Rocket History to test spray shape and volume at supply pressures consistent with fuel pressures specified for the injector head of summer 1944. The test system features an adjustable pressure regulator and fluid pressure gauge. For test purposes the device was simply connected to a relatively high pressure mains water supply. And although water does not have the same viscosity of the 75% Ethenol to 25% water mix of the V2's fuel it was considered close enough by the German technicians, who regularly used plain water as a substitute when testing issues related to furl flow rather than combustion. A 2131E fuel injector insert is shown installed in the holder at the front of the rig, but as the thread was the same on all inserts the nozzle can be changed for other models easily with aid of a pin spanner. See video for a demonstration of this simple test system.
Fuel injector inserts for production series 18-pot injector head. The top row shows the injector face, second row shoes the same types from the rear. The lowermost insert have been halved to reveal the cavity shape, orifice edge, inlet and cooling apertures. Note that the insert in column A, 2131E, is two piece construction, and pressed together for assembly (see additional photo). On test, the parts had to remain together under a separation force of 300kg.
Fuel injector inserts for production series 18-pot injector head showing general shape and thread position. For further details see associated image. The lowermost insert have been halved to reveal the cavity shape, orifice edge, inlet and cooling apertures. V2RH image
Cutaway section of fuel and liquid oxygen (LOX) injector pot. The exhibit shows the bell shaped thick inner wall of the burner with three tiers of fuel injector inserts (A,D, and E). The central copper alloy LOX spray injector is also well displayed in this image. The thin steel outer shell of the burner cup is shown and affords a good view of the head cavity that supplies fuel to the injector inserts - one A type injector is shown party cut through on the right, its rear portion showing inside the fuel cavity. V2RH image
Cutaway section of fuel and liquid oxygen (LOX) injector pot. The exhibit shows the bell shaped thick inner wall of the burner with three tiers of fuel injector inserts (A,D, and E). As well as the two rows of plain drilled apertures B and C. The central copper alloy LOX spray injector is also well displayed in this image and shows the three letter armament code of the manufacturer (elr = H.K. Rudolf, Pilsen) and the 1943 date of manufacture on one face of the hex nut. Note the close proximity of the tier A injector inserts to the LOX injector. The spary from these injectors plays directly onto the lower section of the LOX spray head. This section of the burner cap had the lowest temperature and as a result tier A insert did nor require cooling pres. See associated picture. V2RH image
Standard fuel injector inserts for production series 18-pot injector head. Insert 1 (3304D/3305D) shows four thin wires demonstrating the angles of all four 'cooling' pores. Insert 2 (3305D/2131E) has two 1.3mm twist drill showing the edge bores for the gyroscopic swirl inlets. Insert 3 (3305D) shows another view of the cooling pore angle and origin. V2RH image
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
25-Ton aluminium injector head showing mpe armament code for the Heimat-Artillerie-Park 11 (HAP11) Karlshagen Werk Nord.
Relics of the A4 25-ton 1941 aluminium injector head. See other photos in this series for more detail. Photo courtesy Horst Beck Collection
Part of the 'Standard' series A aluminium head from 1941 to early 1942. Showing the position of standard type LOX injector. The brass fuel injector inserts type and position pattern on the relic seem to be of the standard type with the row of 3 inlet aperture type inserts positioned furthest from the LOX injector. Photo courtesy Horst Beck Collection
Relic of prototype A4 25-ton 1940/41 aluminium injector head basket (or pre-chamber) showing 68 copper alloy inserts in 5 rows. The standard configuration would later become 44 inserts in 3 rows 25 2mm diameter drilled holes in two rows situated at row 3 and 4 (counting from nearest the camera). Photo courtesy Host Beck Collection
Relic of A4 25-ton 1940/41 aluminium injector head basket (or pre-chamber) showing 68 copper alloy inserts in 5 rows. The standard configuration would later become 44 inserts in 3 rows 25 2mm diameter drilled holes in two rows situated at row 3 and 4 (counting from nearest the camera). Photo courtesy Host Beck Collection
Flown V2 thrust chamber relic from February 1945. Badly damaged from impact, this head shows 4 intact LOX input pipe connections as well as exposed fuel injector inserts positioned in the inner wall of the injector pots. The inner and outer walls of the head are also conveniently exposed on this exhibit. Photo www.v2rockethistory.com
V2 Rocket History Museum Relic: This cutaway presentation shows one of the V2's 18 combined fuel and liquid oxygen (LOX) injector 'pots'. The LOX injector transit cap is also shown. The pot shown here is sometimes incorrectly referred to as a pre-burner or pre chamber - a mixer or diffuser pot probably describes its role more accurately.
This relic from the V2 Rocket History collection shows a cutaway presentation of one of the V2's 18 combined fuel and liquid oxygen (LOX) injector 'pots'. The LOX injector transit cap is also shown fitted over the LOX injector.
One of the V2's 18 injector pots showing fuel and LOX injector copper alloy inserts. The spray head A is for liquid oxygen (LOX) and the numerous small injectors lining the chamber are for the fuel. The term pre-chamber is a throw-back to a time when combustion systems developed at the Kummersdorf test facility had a closed structure rather than the open bucket design seen here. Image Horst Beck Collection
Image shows interior of production series (combat relic) V2 missile propellent injector pre-mixer pots. Three post in the picture are intact, others seem in the picture have been destroyed in the impact. This engine part was recovered from a combat impact East of London. Impact date: February 1945
