Noise from Intermittent Jet Engines and Steady-Flow Jet Engines with Rough Burning
Abstract
Sound measurements were made on a pulsejet and a subsonic ramjet of the types used for helicopter rotor drive and on a turbojet with afterburner. The pulsejet was found to produce a discrete-frequency spectrum having a single predominant component corresponding to the engine firing frequency. The angular distribution was slightly directional, with the largest sound pressure occurring to the rear of the engine and near its axis. It was found that an estimate of the noise level from a pulsejet could be made by application of resonant-tube theory, if certain of the average flow parameters of the engine are known or can be reasonably approximated. The small subsonic ramjet and turbojet with afterburner were both found to produce discrete-frequency noise spectrums. Their spectrums, however, contrasted with that of the pulsejet in that they contained several harmonic components of magnitude comparable with that of the fundamental.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1952
- Accession Number
- ADB193535
Entities
People
- Leslie W. Lassiter
Organizations
- National Aeronautics and Space Administration