Icing is an issue that has plagued aircraft manufacturers and operators for a long time. Evidently, I’m not talking about cake icing or the hockey infraction. Rather, icing refers to the phenomenon when ice forms on an aircraft’s wings on the ground or in flight. Today, aerospace engineers and researchers are taking significant steps forward in understanding and tackling icing issues, thanks in part to 3D printing.
A joint team from NASA, the Federal Aviation Administration (FAA), the French Aerospace Lab (ONERA) and American universities, have been utilizing innovative research tools, including 3D scanning and 3D printing, to gather vital data about aircraft icing. The new information will be released publicly in 2020 and is expected to make it easier for aircraft manufacturers and operators to address the problem.
“The aviation community has studied icing since before World War II, but thanks to the new tools we have access to we’re still learning new things that can help industry,” explained Andy Broeren, an icing engineer at NASA’s Glenn Research Center (GRC) in Cleveland.
The five-year collaborative project has introduced new research methods, including 3D printing, for gathering data about the formation of ice of aircraft and its effects.
Ice ice baby
Traditionally, research about the icing phenomenon relied on fairly rudimentary methods. For instance, ice would be generated in a special wind tunnel designed to blow super cold water droplets over an airplane surface, which would freeze on contact. To analyze the formed ice, researchers would commonly slice the frozen water using a heated metal plate and trace its contours on a piece of cardboard.
This approach did result in some useful data for computer codes that run simulations, but was limited because of its inherent imprecision. In other words, by tracing the contours of the ice, many of the fine details in the ice structures were lost. Other research efforts have tried to artificially reproduce and measure complex ice structures using molds and castings. These ice-inspired models would then be attached to aircraft surfaces for wind tunnel testing.
Most recently, however, the NASA-led team introduced the use of 3D printing to reproduce icing formations. Specifically, the joint team used 3D scanning to capture ice that had formed in the wind tunnel and 3D printing to reproduce it physically.
Broeren said: “When we started this project, we didn’t have a really good capability to measure the ice in three dimensions and do a high-fidelity 3D printer rendition of it. Now, we do.”
The new 3D printing-based approach could enable aircraft manufacturers to better understand icing and gather data about the effects of ice on aircraft. This would enable existing icing-related regulations and standards to be updated and become more accurate. Presently, the FAA’s safety margins regarding icing are based on dated information gathered years ago.
“If we can improve our understanding of how ice forms and affects aircraft in flight, that higher fidelity data could help us in several important ways,” Broeren added.
Among the benefits of using 3D printing to capture more accurate data about icing are the potential to improve the validity of computer simulation tools that predict ice formation, to enable the FAA to adjust its requirements for certifying a plane’s ability to manage icing and to design more fuel-efficient airplanes.
As mentioned above, the results of the five-year joint research project will become public on May 31, 2020.3