Wing leading-edge technology designed to deliver higher angles of attack for slower airspeeds on approach
Rotating-cylinder wing leading-edges that could enable very slow, low-noise descents will begin computational fluid dynamics studies this month.
The rotating cylinder adds momentum to the boundary layer on the upper surface of the aerofoil and delays airflow separation and wing stall, allowing higher angles of attack and slower airspeeds on approach. With the wing leading-edge cylinders an aircraft’s angle of attack could be greater than 20° before a stall occurs.
“To reduce noise on approach, you want to come in slowly and need high drag and high lift,” says lead cylinder researcher and US Massachusetts Institute of Technology professor Zoltan Spakovszky.
“The leading-edge rotating cylinder could potentially enable very slow and very steep approach profiles. The required angles of attack may make you fall back in your seat, like the Concorde did,” he says.
Spakovszky’s team has yet to estimate the vibration and noise generated by the cylinders and their aerodynamic performance at cruise conditions.
Any noise generated by the rotating cylinders themselves would have to be balanced with any airframe noise reduction due to slower descent speeds.
Leading-edge rotating cylinder research was conducted in the 1950s, but was abandoned as an option for commercial airliners.
Noise is a key design criterion and the cylinder work forms part of the Cambridge-MIT Institute’s Silent Aircraft Initiative (SAI).
SAI will operate until 2006 and has £4 million ($7 million) in funding.
ROB COPPINGER/LONDON
Source: Flight International
