Listening up in the Navy means not just paying attention but being cognizant of the deafening sound emanating from F-18 fighter jets that sometimes fly over residential areas. Starting in December of 2002, noise generated from F-18 engines at full throttle will approach half of what it was at the start of the year thanks to a patent-pending technology developed by Anjaneyulu Krothapalli, the chair of Florida State University's Department of Mechanical Engineering. He reduces noise by siphoning off some of the air travelling through the jet engine and forcing it at high pressure through multiple microjets that fan around the engine's large exhaust. Noise is reduced when the small jets of high-pressure air hit the large stream of lower pressure engine exhaust. "Right now we are trying to figure out the optimum number of microjets that will best suppress noise," says Krothapalli. So far he has achieved a 5-decibel (dB) reduction, but he hopes to achieve a 10-dB noise reduction soon. Krothapalli also reduces noise by forcing water and other liquids through the microjets in place of air. His noise suppression lab uses compressed air at 2,000 psi for simulating running jet engines. In a separate chamber, he measures noise. For more information, call Krothapalli at (850) 644-5885 or (850) 410-6338.
New versions of BASF's Ecovio line are both compostable and designed for either injection molding or thermoforming. These combinations are becoming more common for the single-use bioplastics used in food service and food packaging applications, but are still not widely available.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This radio show will show what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.