Recently NASA engineers at the Dryden Flight Research Center, feed crayons and cereal to a jet engine. No, the engine tests aren't to see how well the Pratt & Whitney F117 turbofan engines hold up against a toddler. The tests are actually to test new sensors to help with managing the health of the engines while in flight.
"The point of tossing cereal and crayons into the engine is to trigger some small change for the sensors to detect, without harming the engine," said Dave Berger, a leader of the Vehicle Integrated Propulsion (VIPR) test series. "Once the sensitivity of the sensors is established, we will end with a real-world scenario by introducing volcanic ash, which really can – and does – tear up an engine."
Photos courtesy of NASA.
The need for such an experiment and new sensors came to the forefront during the 2009 Icelandic volcano eruptions that disrupted air traffic worldwide for weeks. The overall tests on the engine will eventually lead to the introduction to volcanic ash which will destroy the engine.
"Being able to take an overhauled engine and run it all the way to the end of its life through research experiments is a unique opportunity," said Berger.
In true NASA fashion, they also had to design and build two support structures for the experiment. The first was a 24-foot diameter water platform designed to sit below and in front of the research engine during ground testing, the second was a piece of support equipment that is an emission sensor rig designed to sit just behind the engine and sweep across the engine's exhaust path in order to collect exhaust gases for emissions data.
Based at Dryden, VIPR is funded by NASA's Aeronautics Research Mission Directorate, which manages the Aviation Safety Program.