Supercritical wings add a graceful appearance to the modified NASA F-8 test aircraft.
#Wing airfoil full
Read the full article in Physics of Fluids.An airfoil considered unconventional when tested in the early 1970s by NASA at the Dryden Flight Research Center is now universally recognized by the aviation industry as a wing design that increases flying efficiency and helps lower fuel costs. The article “Aeroacoustic Investigation of Asymmetric Oblique Trailing-edge Serrations Enlightened by Owl Wings” was authored by Lei Wang and Xiaomin Liu. The owl wing research, noted the authors, will serve as an important guide for airfoil design and noise control. The researchers said that examining noise reduction techniques under the influence of different incoming flows would make their conclusions more universal. Since the level of noise reduction was dependent on operating conditions, the researchers emphasized that the airfoil designs should be further evaluated based on the specific application.įor example, wind turbines have complex incoming flow environments, which require a more general noise reduction technology. The researchers also pointed out that symmetric trail-edge serrations reduced the noise more so than conventional trailing-edge serrations. They found that they could suppress the noise when they improved the flow conditions around the trailing edge and optimized the shape of the edge. They applied their findings to suppress the noise of rotating machinery.
#Wing airfoil software
The researchers used noise calculation and analysis software to conduct a series of detailed theoretical studies of simplified airfoils with characteristics reminiscent of owl wings. “The noise reduction capabilities of conventional sawtooth structures are limited, and some new non-smooth trailing-edge structures need to be proposed and developed to further tap the potential of bionic noise reduction.” Suppressing Noise in Rotating Machinery “At present, the blade design of rotating turbomachinery has gradually matured, but the noise reduction technology is still at a bottleneck,” said Liu. But these studies also showed that noise reduction could not be generalized-the measure of noise diffusion depended on the final application. Previous research on the effects of serrated trailing edges showed that serrations effectively reduce the noise of rotating machinery. It plays a significant role in the overall airframe noise. The researchers explain that when that layer of air flows back through the trailing edge, it scatters and radiates noise. The flow forms a turbulent layer of air along the upper and lower surfaces of the airfoil. It is generated when airflow passes along the back of an airfoil, such as the wing or blades of the propeller, rotor or turbine. Moreover, Liu added, when the owl catches prey, the shape of the wings is also constantly changing, which underscores the significance of studying the wing edge configuration during owl flight. “Nocturnal owls produce about 18 decibels less noise than other birds at similar flight speeds due to their unique wing configuration,” said Xiaomin Liu, a co-author of the paper, which is published in Physics of Fluids, by AIP Publishing. Researchers from Xi’an Jiaotong University, based in Xi’an, Shaanxi, China, had good reason to take their cue from nocturnal owls.
0 kommentar(er)
