Fitting Jet Noise Similarity Spectra to Volcano Infrasound Data

Similarity spectra analysis of high-performance jet aircraft noise.

Noise measured in the vicinity of an F-22A Raptor has been compared to similarity spectra found previously to represent mixing noise from large-scale and fine-scale turbulent structures in laboratory-scale jet plumes. Comparisons have been made for three engine conditions using ground-based sideline microphones, which covered a large angular aperture. Even though the nozzle geometry is complex ...

Fitting circles to data with correlated noise

We study the problem of fitting circles to scattered data. Unlike many other studies, we assume that the noise is (strongly) correlated; we adopt a particular model where correlations decay exponentially with the distance between data points. Our main results are formulas for the maximum likelihood estimates and their covariance matrix. Our study is motivated by (and applied to) arcs collected ...

Session 3aNSb: Aviaton, Aviation Engines, and Flow Noise 3aNSb4. Comparison of supersonic full-scale and laboratory-scale jet data and the similarity spectra for turbulent mixing noise

Broadband, partially correlated noise radiated from supersonic jets has characteristics that scale with nozzle size and flow properties. In particular, the spectral content of jet noise and variation with angle in many cases agree with empirically derived similarity spectra for large and fine-scale components of turbulent mixing noise [Tam et al., AIAA paper 96-1716]. In previous studies, measu...

Introduction to an Open Community Infrasound Dataset from the Actively Erupting Sakurajima Volcano, Japan

Effects of Co-Exposure to Noise and JP-4 Jet Fuel on Hearing Loss in Rats

Background and Aim: Autotoxic substances such as JP-4 jet fuel can have negative effects on the auditory system by the various means such as cochlear dysfunction. The purpose of this study was to investigate the combined effects of exposure to JP-4 jet fuel and noise on hearing loss in rats, to determine the possible interference effects of these two risk factors on rat auditory system. Methods...