The retirement of the supersonic plane Concorde in 2003 was the end of an era in aviation history. Almost two decades later, the world is once again primed for supersonic aircraft and even going a step further to develop hypersonic ones. A recently published study uses 3D printing technology to tackle the main issue of hypersonic travel: overheating.
Traveling at Mach 5 sounds great. But to achieve this, there are many hurdles that we still need to cross. It is not just about making engines that can produce massive amounts of thrust, there is also the issue of friction between the moving aircraft and the atmosphere. For decades now, scientists have looked at fuels that absorb heat to also act as a coolant to resolve this issue.
For these fuels to work, the heat exchange has to be highly efficient and is supported by catalysts. These are substances that take part in chemical reactions but do not get altered themselves. For hypersonic flights, the space available for these catalysts to work their magic is also constrained, said Roxanne Hubesch, a Ph.D. researcher at RMIT University in Australia and the first author of the study.
So, Hubesch and her team of researchers used 3D printing to create metal alloy lattice structures and then coated them with synthetic materials called zeolites. The team created many experimental structures that served as a testing ground for the extreme conditions that hypersonic travel will entail. As the metal heated up, it reacted with the zeolites and this mix of metal and synthetic minerals worked like 'miniature chemical reactors' that showed 'unprecedented catalytic activity,' Hubesch said in a press release.
Researchers still need to figure out the right mix of alloys that will have the highest efficiency and work is currently ongoing to optimize the performance that will make supersonic flights possible again.
The technology can be used in any other process that might be marred by overheating issues but has application in other fields too. The researchers want to use their work to trap pollutants from vehicles and even improve indoor air quality using small devices, the press release said.