Researchers Turn Down Jet Volume
Scientists at Ohio State University are working on a "mute button" for jet engine exhaust noise. Researchers Mohammad Samimy and Igor Adamovich have used high-voltage electrical current to change the patterns of exhaust turbulence, one of the main causes of engine noise. If they can turn it into a practical system, they'll give pilots the option of setting the volume on their engines based on where and when they're flying. Modern jet engines already have a mechanical version of the same theory. Zigzags cut in the exhaust nozzle direct the gases to control noise, but they also increase fuel consumption. The Ohio State system would allow pilots to hush their engines on takeoff and let them run at their noisiest efficiency at altitude. NASA has contributed $100,000 to help fund the research.