Acoustic testing covers a wide range of applications. ATA Engineering has experience with environmental acoustics, interior sound quality, fluctuating pressure fields, flight testing, ground testing for engine or operational noise, acoustic holography, launch vehicle acoustic qualification, and other vibro-acoustic applications. The type of measurement varies depending on the application. Microphones, pressure transducers, and sound level meters are typical transducers used in the acoustic tests that ATA performs and analyzes. Acceleration and strain measurements are also valuable data that are recorded in parallel with microphones or pressure transducers.
Wave speed and damping testing are valuable methods used to measure acoustic properties of a variety of materials. ATA has performed this kind of testing on composite and aluminum materials with different types of damping treatment installed.
Acoustic Qualification Testing
Acoustic qualification testing is commonly performed to evaluate loads induced by launch vehicles from airborne noise. ATA has experience utilizing reverberant acoustic chambers and direct field acoustic testing using loudspeaker arrays in the qualification process. The photo below shows a joint project using stacked loudspeakers to perform an acoustic test at NASA JPL. ATA was consulted to optimize data acquisition and post processing of the data.
Acoustic Flight Testing Solutions
ATA provides support for acoustic flight test programs. Our experience includes recording microphone and acceleration measurements during flight to quantify noise paths and sources in the aircraft cabin, engine compartment, and other cavities. These measurements are key inputs for Statistical Energy Analysis (SEA) models that are used to rank noise paths and sources. The models are then used to evaluate noise reduction and interior design modifications to optimize the cabin noise reductions. Overall weights and noise levels are reduced as a result, saving money and increasing quality passenger comfort.
Fluctuating Pressures in Jet Plumes
ATA Engineering has developed a unique solution to measure fluctuating pressure levels and vibration response inside the jet plume of a solid rocket motor. Many challenges had to be overcome to accomplish a successful test including the extreme temperatures and harsh environment. A total of twelve pressure transducers, eight accelerometers, and three thermocouples were recorded for a 20 second burn of a solid rocket motor. The measurements are key components to validate analytical methods that are being used to predict the response of a structure due to loads induced by jet plumes.