Application of Active Noise Control to Reduce Cabin Noise in Single Engine General Aviation Aircraft
Date of Award
Thesis - Open Access
Master of Aerospace Engineering
Dr. Howard V. L. Patrick
Dr. Donald T. Higdon
Mr. Charles Eastlake
The application of active noise control to reduce cabin noise in single engine, general aviation aircraft is investigated through the use of the 'filtered x' least mean square algorithm and a simple acoustic feedforward method to generate a reference signal is tested. The system is designed to utilize one reference signal and up to two feedback signals and two audio speakers. The feedforward system consists of a microphone placed in close proximity to the front windshield and isolated from the cabin noise. Cabin noise and reference signals are recorded during flight in a Cessna 172 Skyhawk, a Piper Cherokee 140 and a Piper Malibu Mirage. The recorded data is used in laboratory tests to evaluate the capability of the control system to reduce the cabin noise signal with the recorded reference signal. The reference signal was found to lack coherence with the cabin noise in most aircraft which limited the noise reductions. Alternative feedforward methods are investigated and an alternative reference signal is tested in a laboratory simulation. The results with the recorded data and the modified reference signal are detailed in each case.
Scholarly Commons Citation
Dolmans, Jeroen Hendrik, "Application of Active Noise Control to Reduce Cabin Noise in Single Engine General Aviation Aircraft" (1997). Master's Theses - Daytona Beach. 45.