Geometric near-field characteristics of supersonic jets: Full and laboratory scales

Sound pressure measurements were made in the geometric near field of a full-scale jet installed on a military aircraft. In this work, levels at 11.7 m (near the 42-ft foul line) are reported. Weighting curves that account for listener factors are applied to the overall sound pressure level, including A-weighting, C-weighting, and D-weighting. In addition, the effect of representative double hearing protection on A-weighted overall level is shown.A useful limited comparison is made between a laboratory-scale, Mach-2.0, unheated jet and the full-scale jet engine at the same scaled distance from the jet centerline.