Jet Mixing Noise from Fine-Scale Turbulence

摘要: It is known that turhulent mixing noise from high-speed jets consists of two components. They are the large turbulent structures in form Mach wave radiation and less directional fine-scale turbulence noise. The dominates downstream direction. sideline upstream directions. A semiempirical theory developed for prediction spectrum, intensity, directivity turhulence method self-contained. information supplied by k-e model. contains three empirical constants beyond those These determined best fit calculated spectra to experimental measurements. Extensive comparisons between measured over a wide range directions radiation,jet velocities, temperatures have heen carried out. Excellent agreements found. believed present offers significant improvements current or jet methods use. There no first principle at time.