German aerospace researchers believe predictive load-alleviation can improve fuel consumption by more than 7% while improving passenger comfort.
The conclusion is based on windtunnel testing conducted under a project known as ‘OLAF’ to examine optimal load adaption.
But the German aerospace centre DLR is seeking to demonstrate the technology further with installation of prototype systems in a research aircraft.
“Initially, we saw load control primarily as a method for reducing weight, but now it seems to be a key element for future wing design – with significantly improved aerodynamics and greater efficiency,” says project manager Lars Reimer, of the centre’s aerodynamics and flow technology institute.
The concept combines laser and lidar sensors to detect gusts ahead of the aircraft and respond with rapid adjustments to the flight-control surfaces in order to absorb the turbulence and minimise structural load.
OLAF examined the design of long-haul aircraft to assess the technology and compare the performance with conventional configurations through simulations.
“The new technology enables wings with a greater span and higher aerodynamic efficiency,” says DLR.
Researchers from the centre’s aeroelasticity division sought to verify these findings with low-speed windtunnel tests at Braunschweig.
These tests involved constructing a flexible wing with adaptive trailing-edge surfaces and spoilers and subjecting it to gusts from a specially-developed mobile generator.
Vibrations on the wing were measured both with and without load control activated, says DLR, adding that the vibration was reduced through load control, and cut stress at the wing root by up to 80%.
“Use of state-of-the-art load-control systems not only reduces material stress and extends service life, but also improves the aerodynamics and efficiency,” says Reimer, adding that the technology could lower fuel-burn by 7.2%.
Along with the proposed aircraft testing, the OLAF research aims to provide aircraft manufacturers with methodology to incorporate load-alleviation into structural designs from the outset.
