Investigation of Structural Dynamic Interactions on the U.S. Army Helicopter Icing Spray System

摘要

A unique JCH-47 Chinook helicopter is operated by the U.S. Army Airworthiness Qualification and Test Directorate for the purpose of aircraft icing research (see figure 1). Special equipment installed in this aircraft include an internal water tank and a large external tubular structure which is capable of producing a water droplet field of up to 300 square feet. Undesirable oscillations in this external structure have been attenuated through the application of modal analysis and structural modification, using commercially available equipment and software. Flight testing and in-flight vibration measurements have verified the effectiveness of this approach.