The Vibration and Acoustic Effects of Prop Design and Unbalance on Small Unmanned Aircraft

Abstract

The vibration and acoustic effects due to prop design, damage, and unbalance on a popular small unmanned aircraft systems (sUAS) is presented. The use of sUAS or drones is becoming ever more popular for hobbyists, as well as in commercial and military operations, and the influence of props on the vibration and acoustic environment are of interest. Many types of props are available for use on sUAS that promise extended run times, increased performance, and quieter operation. While many systems promise these results, few studies have been conducted to measure and evaluate their true performance. Therefore, this review provides data obtained by experimentally measuring the vibration levels onboard the host aircraft as well as the acoustic levels produced. The data is analyzed to gain further understanding of the vibration and acoustic properties and make predictions on prop performance. The fundamental frequencies of the aircraft are found along with the acoustic signature. These two outcomes are compared and studied to find the correlation between them. The analysis will utilize an airframes that is commonly used in the UAS community along with frequently used props that are balanced and unbalanced and with and without damage. The data is obtained from aircraft fully powered and airborne in a hovering or level flight configuration. This study provides sUAS operators the information required for choosing the most effective prop design to effectively reduce vibration and acoustic sound levels.