• Next step: Let’s make planes quieter

    (Illustration by Yun Jing, North Carolina State University )

    Keeping airline passengers from going insane with a membrane. (Illustration by Yun Jing, North Carolina State University )

    Let’s dispense with the figurative baggage surrounding air travel, the declining leg room and the reclining seat incursions. Passengers are unlikely to feel more comfortable in their seats, at least not in economy class.

    Instead, the next advancements might come in the area of cabin noise. Researchers at North Carolina State University and MIT have developed a lightweight membrane to block low frequency noise in aircraft, the drone of the engines that contributes to passengers’ discomfort and sells a lot of noise-canceling headphones.

    “It’s particularly effective against low-frequency noise,” says Yun Jing, an assistant professor of mechanical and aerospace engineering at North Carolina State. “At low frequencies – sounds below 500 Hertz – the honeycomb panel with the membrane blocks 100 to 1,000 times more sound energy than the panel without a membrane.”

    The parts of an airplane cabin’s structure that makes it strong and safe and lightweight do a great job of making it more fuel efficient but don’t do much for blocking noise. But this membrane, about .25 millimeters in thickness, bounces the sound waves off of it and only adds 6 percent to the weight of the panel.

    “The membrane is relatively inexpensive to produce, and can be made of any material that does not impact the structural integrity of the honeycomb panel,” says Ni Sui, a Ph.D. student in Jing’s lab and lead author of the paper. “It could make flying much more pleasant for passengers.”

    If you enjoy academic papers, read the original paper, published in Applied Physics Letters.