NASA Glenn researchers are going back to basics to probe deeper into the physics of high-altitude ice crystal icing.
Measuring the conditions that lead to a build-up of ice crystals inside an engine has been a challenge, according to researcher Peter Struk.
“You can’t come in with probes to measure exact concentrations of water and ice particle sizes because you can’t block the airflow into the engine,” he said. “We wanted to figure out a way to do the same type of test, but expand it with a bigger area so we can better understand what is happening.”
The answer was to go back to the fundamentals and conduct a dedicated test to simulate the high-altitude ice crystal environment outside of the engine.
“When you are trying to understand the physics of a problem, you need to break it down into the simplest possible fashion," said Struk, who led the fundamental test in June.
A research wing was then exposed to an icing cloud simulating the in-flight conditions in a free jet, unattached, configuration in NASA Glenn’s Propulsion Systems Laboratory. A new instrument traversing system allowed researchers to use multiple probes during the test to record particle size, water content and temperature.
Pressure and temperature were replicated with the data from computer models and measurements of previous aircraft engine tests. Computer simulations were then used to estimate air flow velocities.
“We’ve been able to vary conditions in the test to see how individual parameters affect icing,” said Struk. “Understanding this can lead to predicting icing patterns on future flights.”
Tests such as this will allow researchers to build databases with the various conditions and their possible ice formations.
NASA Glenn’s researchers are hopeful that these predictions can be used to design an engine model to reduce ice crystal icing during future flights.