A segment of the sandwich nozzle will be exhibited at the Paris Air Show and a full-scale demonstration will follow this autumn on the Vulcain 2 engine.

For the current Ariane rocket nozzles, Volvo Aero welds many hundreds of thin tubes next to each other to form a large cone with a complex manifold, which discharges exhaust gases from the rocket engine. Much of the nozzle work is manual – which has its disadvantages.

The new demonstrator Nozzle – (SWEA), which utilizes the sandwich technology developed by Volvo Aero, is entirely smooth on the inside – and does not have a manifold. The hundreds of cooling tubes have been replaced by two sheet-metal cones, with an inner cone that uses automated ultra-sound-controlled milling to achieve precision machining to some hundredths of a millimeter in sheet metal with a minimum thickness of 0.6 mm. An outer sheet-metal cone is welded on to the inner sheet-metal cone by automated laser welding using real-time X-rays that detect the hidden weld joint.

The “reinforcement jacket” on SWEA uses no less than 15 km of MD welding (laser Metal Deposition). Yet the automated MD welding takes only a third of the time needed to manufacture the current Vulcain 2 nozzle reinforcement jacket.

The result is a substantially stiffer and more robust sandwich nozzle. Reliability is enhanced.
The risk of the sandwich nozzle succumbing to defects is drastically reduced. Our development process has already generated a number of patents and the sandwich nozzle can be used in many different types of rocket engines.

Volvo Aero did not develop the next generation of sandwich nozzle by itself. 

“We worked closely and very productively with the SNSB, CNES, DLR, ESA, Snecma and EADS,” says Roland Rydén, SWEA Project Leader.

This autumn, the design is planned to be hot tested on the Vulcain 2 engine under the ESA’s Ariane research and technology support program (ARTA program). Later in the autumn a smaller sandwich nozzle “SCENE” will be delivered for hot testing by the EADS and DLR inside ESA’s FLPP program High Thrust Engine effort.

“Accordingly, we hope that our SWEA sandwich nozzle design will reach Technology Readiness Level 6, meaning that it is at a stage of development and maturity where it can be used in development activities,” said Roland Rydén.

June 15, 2009

For more information, contact Roland Rydén, Project Leader Sandwich Nozzle, +46 520 94092

Ulf Palmnäs, Deputy Vice President Business Development, is on site at the Paris Air Show and is available on phone on Monday before 12:00 noon on +46 705690 432.

Photos are available in our images gallery.