Title: Acoustic Design and Performance of Turbojet Test Facilities
text: THE high noise level associated with turbojet testing creates two noise problems: 1. The reduction of noise in the neighborhood of the installation to an acceptable level. 2. The protection of operating personnel from excessive noise. Desirable sound levels are established and, on the basis of these levels, specifications are written for the acoustic treatment of the turbojet facilities. The acoustic treatment must not only be satisfactory from the point of view of noise reduction, but it must also be able to withstand the very rigorous operating conditions. High-temperature and high-velocity flow of gases through the exhaust stack makes for these rigorous conditions. Designs which meet these specifications are discussed in this paper, together with performance data obtained on these designs.