The nozzle withstood more than 1,040 seconds at high combustion chamber pressures and temperatures. Credit: NASA/MSFC/David Olive.

Engineers at Nasa’s Marshall Space Flight Centre in the US has developed and validated a new additive manufacturing technique that can be used to produce a rocket engine nozzle.

The new process known as Laser Wire Direct Closeout (LWDC) has been developed and advanced at Nasa under the agency’s Small Business Innovation Research programme.

LWDC uses a wire-based additive manufacturing process to precisely close out the nozzle coolant channels. This includes a high-pressure coolant fluid that protects the nozzle walls from the high temperatures.

Nasa has already received the patent for the technology, which could help reduce cost and build time from several months to several weeks.

“The technology has already been licensed and is under consideration for use in commercial applications across the industry.”

Nasa Marshall Engine Components Development and Technology Branch senior propulsion engineer Paul Gradl said: “Our motivation behind this technology was to develop a robust process that eliminates several steps in the traditional manufacturing process.

“The manufacturing process is further complicated by the fact that the hot wall of the nozzle is only the thickness of a few sheets of paper and must withstand high temperatures and strains during operation.”

The LWDC process has been used by US-based Keystone Synergistic to fabricate and test a nozzle.

Nasa engineers have carried out hot-fire testing to put this nozzle through its paces, accumulating more than 1,040 seconds at high combustion chamber pressures and temperatures.

The technology has already been licensed and is under consideration for use in commercial applications across the industry.

In addition, engineers have tested an abrasive waterjet milling process that can form coolant channels developed by US-based Ormond.

Arc-based deposition technology has also been under development to additively manufacture the near net shape liner that would contain the water jet milled channels.