1. A PRELIMINARY ACOUSTIC INVESTIGATION OF A COAXIAL HELICOPTER IN HIGH-SPEED FLIGHT Open Access Author: Walsh, Gregory Daniel Title: A PRELIMINARY ACOUSTIC INVESTIGATION OF A COAXIAL HELICOPTER IN HIGH-SPEED FLIGHT Graduate Program: Aerospace Engineering Keywords: AcousticsCoaxial HelicopterRotorcraftRotorcraft AcousticsHelicopter File: Download Walsh_Thesis.pdf Committee Members: Kenneth Steven Brentner, Thesis Advisor/Co-AdvisorJacob Willem Langelaan, Committee MemberGeorge A Lesieutre, Committee Member