Ted Schultz' contributions to aircraft acoustics

Abstract

Ted Schultz' contributions to aircraft acoustics began in 1955 during the initial design of the DC‐8 jet transport airplane at the Douglas Aircraft Company in Santa Monica, CA. As Assistant Chief of the Acoustical Engineering Staff, he was directly involved in theoretical and environmental work in interior and exterior acoustics and provided challenging leadership to other Douglas employees. Ted's work in aircraft cabin acoustics included design and testing of: fuselage sidewalls with high sound transmission loss against the pressure fluctuations in the turbulent boundary layer (whose characteristics were not well understood at that time); interior sound‐absorbing surfaces; and methods to control the noise produced by aircraft equipment items (e.g., hydraulic pumps, fans, venturi flow‐control devices, and air‐conditioning system components). During much of this experimental work, he found it necessary to develop unique acoustical laboratory test facilities and techniques which became an expertise widely sought after throughout his later professional career. In exterior acoustics, he worked closely with Alan Powell (consultant to Douglas Aircraft Company) to develop theoretical descriptions of the characteristics of noise resulting from the mixing processes in aircraft jet engine exhausts, as well as in the boundary layer along an aircraft fuselage. He provided insight and guidance in evaluation of results from model and full‐scale jet noise suppressor concepts. Ted also helped in the early development of methods to evaluate community noise impact from operation of jet aircraft. His expertise on rating community noise response considering aircraft and other exterior sounds is recognized worldwide. His highly developed skills in aircraft acoustics were called upon again in the 1984–1988 period as a consultant to McDonnell Douglas in the design of state‐of‐the‐art acoustical test facilities to study methods to minimize cabin noise levels in propfan‐powered transport aircraft. Ted's innovative contributions to all aspects of aircraft acoustics formed technical foundations that will be utilized in establishing acoustical designs for commercial transport aircraft for years to come.