AeroSystems develops acoustic and thermal imaging system

AeroSystems, in cooperation with our FluiDyne Laboratory, has developed a new way of "seeing" an engine under test. In addition to high definition video imaging, AeroSystems now offers add-on packages that allow thermal and acoustic imaging. These packages give test cell operators another tool to help diagnose engine anomalies and verify engine performance during testing.

"For many years our FluiDyne lab has applied thermal and acoustic imaging technology on subscale engine models to help our OEM customers design safer, quieter engines. It wasn't until recently that we realized the benefit this type of system has in an engine test environment," said Grant Radinzel, Vice President of Product Management & Development.

AeroSystems thermal imaging package displays the heat signature produced by the engine. Engine and test hardware anomalies are often revealed through thermal imaging long before traditional methods. Engine casing hot spots can indicate and improper build in an engine overhaul; hot spots in an exhaust stream can indicate a failing fuel nozzle or mixer anomaly. Detecting anomalies like these early helps increase test cell productivity, reduces the likelihood of compromised test data, and/or risk of damage to the engine and equipment.

The acoustic imaging package displays sound source and intensity with color graphics overlaid on a digital video image. Color bands range from blue to red for increasing sound intensity. Sound intensity created by engine machine dynamics is created by components within the engine at predictable frequencies. For example, a fan blade rub “noise” will happen at a frequency proportional to the engine speed times the number of fan blades. AeroSystems acoustic imaging package would indicate a red or orange tinting of the fan area to indicate engine blade rub. To the human ear, this particular “noise” could be completely drowned out by engine other noise, but it is “seen” by the acoustic imaging package. Similarly, other engine machine noises occur at predicable frequencies such as bearing failures and pump oscillations. With the acoustic imaging package, anomalies such as those can be “seen” by the operator without having to enter the test cell during high power setting, and without a lot of technical training on how to interpret vibration system plots.

"We are always looking for ways to improve engine testing for our customers. We see thermal and acoustic imaging technology as a critical component in advancing engine testing technology. It is just one more way our customers can make their engine tests more safe, accurate, and productive," said Radinzel.