Canada is set to carry out detailed research on reducing landing gear slipstream noise, a significant contributor to an aircraft's overall noise footprint on its approach to land.
The National Research Council of Canada (NRC) has set aside a wind tunnel in Ottawa, one of eight operated by NRC Aerospace, and has outfitted it with an acoustic liner and precision noise measurement technology. NRC's aerodynamics experts disassemble landing gear, then reassemble it part by part, measuring the noise generated by wind flowing around each component as well as that caused by components interacting.
The body behind the research is Canada's Green Aviation R&D Network (GARDN), a federally established, business-led network, including participants like Bombardier Aerospace, Bell Helicopter, Pratt & Whitney Canada and CMC Electronics working with nine universities to help manufacturers produce greener aircraft.
In the next ten years, International Civil Aviation Organisation standards will demands reductions in noise generated by commercial aircraft by 32dB relative to the current standard.
"Turbulent flow around landing gear generates a significant proportion of the total noise output of an aircraft in close proximity to the ground," said NRC's Stuart McIlwain, group leader of fixed-wing aerodynamics. NRC Aerospace has already tested a full-scale Bombardier Learjet 60 landing gear. NRC aeroacoustics researcher Jerry Syms explained: "We looked at the gear struts and axles individually, but also the interaction between such components. The drag strut/main strut combination, gear doors, brake lines, wheel wells and other components generate enough noise on their own to merit attention."
The NRC says it can offer its acoustic expertise to all aircraft equipment manufacturers.