Archives: Gmedia Albums

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.

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.

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.

3305D fuel injector insert showing swirl cone nebular, and 4 steady steams emanating from cooling pores.

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.

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.

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

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.

Single fuel injector water test rig showing a 3305D bress insert about to be tightened home using a pin-wrench. 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.

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.

The chart shows water delivery in litres per minute per injector

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

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

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.

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

Bomb damaged F1 factory 1945. The huge V2 rocket factory shown badly damaged by air attack at the end of the war in May 1945

Incomplete V2 missile on rail transporter. All 4 control compartments are well shown. The fuel tank connection pipe can be seen but not much else. All of the control equipment has been removed. Plainly visible is the chicken wire holding the fiber wool tank insulation in place. Today this would be called ‘Galvanised hexagonal network restraining matrix, and be supplied by a blue chip Aerospace company for $800 per square inch. In the 1940s, it was just chicken wire at a 2 dollars for a 100 ft roll.

Control compartments 1 (upper) & 4 (lower) Image copyright Imperial War Museum

Control compartments 3 showing gyro mounting platform with two gyros and DC motor driven 3 phase AC voltage generator. The alcohol tank pressurisation pipe is also shown running through the equipment bay (large silver coloured pipe). Image copyright Imperial War Museum

Control compartments 1. Image copyright Imperial War Museum

Control compartment 2 showing plywood separation panels, Oemig umformer (DC to 3 phase AC voltage generator), and voltage frequency control box. Towards the rear the ground connection plugs can just be seen and the mechanism of the cable release trap door (see cat flap!). Image copyright Imperial War Museum

Control compartment 1 top right, 2 top left, 3 bottom left, and 4 bottom right. The fuel tank pressurisation pipe upper connection point is well shown at about 6 o’clock (compartment 3) and just above and to the right the upper plate of the air (N) tank rack (tan colour). Image copyright Imperial War Museum
showing plywood separation panels, Oemig umform