Sometimes, innovation is all about scalability — adapting an industry-specific solution to more widespread commercial use. The challenge doesn’t always lie in the technology itself. Production costs can also present obstacles to commercializing a solution that has game-changing potential but is too costly to implement.
Clearance control coatings for aircraft turbines deliver demonstrated results in reducing fuel consumption and CO2 emissions in the aviation industry. Applied on the compressor and turbine sides, they reduce the gap between the compressor housing and impeller. This lowers the compressor outlet’s temperature and creates the fuel efficiency and emissions benefits. But replicating those results affordably for the automotive sector represented a challenge that the industry struggled to solve.
Aircraft turbines and automotive turbochargers share many characteristics. Jet engines draw cold air from the front into a chamber, where it burns with fuel before it is blasted from the back as hot air. Next, it exits past a turbine — which is in some respects like a compact metal windmill — that drives the compressor, or air pump, at the front of the engine. This pushes the air into the engine to make the fuel burn properly.
Similar principles apply in the operation of an automotive turbocharger in a piston engine. Exhaust gas drives a turbine that spins an air compressor, which pushes extra air (and oxygen) into the cylinders. This makes it possible for them to burn more fuel per second — which is to say, more power.
Internal combustion engines equipped with a turbocharger or supercharger can achieve increased power output per displacement. The escalation of power makes it possible to equip cars with engines that are lighter and smaller, reduce friction and heat transfer losses, but maintain their capacity and performance. By reducing weight without compromising power output, one can reduce fuel consumption and emissions.
Success in the aviation industry had already demonstrated that coatings enhance turbine efficiency. There was no doubt that clearance control coatings would reduce the gap between a turbocharger’s compressor housing and the turbine, which would again result in improved efficiency. But cost was an obstacle to implementation at a scale that would be economical for the automotive manufacturing. Thus, the search was on for a solution that would make the use of clearance control coatings in turbochargers inexpensive enough to be feasible for the automotive sector.
In 2016, Scott Wilson and a team of engineers and managers at Oerlikon Metco developed and tested a new clearance control coating material. The breakthrough significantly reduced costs with an innovation that provides the technology mass-market accessibility.
The technology will soon be available commercially, with the first industrialized application focused on coating turbochargers with clearance control materials to improve efficiency and increase boost pressure.
“Market analysis shows that the most likely coated turbocharger application will be for medium type turbochargers in trucks,” Lüthy says. “We are working very closely with the largest manufacturer of automotive turbochargers and our joint industrialization for the truck market is expected to start in 2018.” Once the investment in clearance control coatings for turbochargers produces increased efficiency in trucks, cars and light vehicles are likely to follow. It is expected that following implementation by early adopters, integration of clearance control coatings for turbochargers in vehicles of all sizes will accelerate beginning in 2021.
Being first to market with lower-cost clearance control coatings is gratifying. But as this story shows, the quest for innovation is really about something bigger than creating materials with new properties. The goal is always to create a solution that improves life or safeguards the planet. Each time a new coating material promotes more environmentally friendly mobility solutions, invention and society flourish together.
By Randy B. Hecht