APU Silencing Technology Development

The proposed effort will result in an "universal" fan noise cancellation system for use with high performance fans used extensively in defense applications including auxiliary power unit (APU) applications. Fans are a critical noise source that impact the audible detection range of the platform. The importance of the fan noise for detection continues to increase as other technology improvements such as fuel cells and signature reduction technologies impact APU noise levels. Successful development of a prototype active noise cancellation system for fans has the potential to make a significant improvement in audible detection range reduction, further enabling mission execution. The concept system includes both sensors and cancellation sources that are integrated into the fan and fan shroud. This yields an active fan noise cancellation system that is self contained and can be integrated into a fan design with minimal effort and with negligible impact on flow performance. The estimated cost and weight burden are comparable with less effective passive noise reduction solutions.