Download or read book Prediction of Broadband Shock associated Noise in Static and Flight Conditions written by Cyprien Henry and published by . This book was released on 2012 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work aims at developing a statistical prediction method for BroadBand Shock-Associated Noise (BBSAN), following recent work from NASA and Boeing. The approach is similar to studies performed for mixing noise models.First, a methodology has been developed to compute the mean turbulent _ow _eld using the Reynolds Averaged Navier-Stokes (RANS) equations. These equations are solved with elsA, a solver developed by ONERA. Most calculations have been performed on academic configurations. An extensive test campaign has been conducted on these configurations at Ecole Centrale de Lyon (ECL), so that calculations have been thoroughly compared to measurements. Mainly, two operating conditions have been tested. The first one is a jet at Mj = 1:15. This condition is typical of a civil engine in cruise. The second operating condition is a jet at Mj = 1:35, which rather concerns military engines.An acoustic model has been developed. It uses the RANS calculation as an input to compute Power Spectrum Densities (PSDs). The intermediate version of the model does not account for refraction effects: acoustic sources are propagated to the far-field using a free field Green's function. As will be seen, this gives good results on simple configurations.The model has been extended to account for refraction effects. This is achieved by computing a Green's function tailored to the problem. A ray tracing method coupled to an adjoint approach has been used to evaluate the Green's function. The computation of the Green's function has been validated for simple cases. The Green's function calculation has been coupled to the acoustic model. PSDs including refraction effects on dual-streamjets are presented.

Download or read book Effects of Simulated Flight on the Structure and Noise of Underexpanded Jets written by Thomas D. Norum and published by . This book was released on 1984 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Survey of the Broadband Shock Associated Noise Prediction Methods written by Chan M. Kim and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Simulated Flight on the Structure and Noise of Underexpanded Jets written by Thomas D. Norum and published by . This book was released on 1984 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Technical Paper written by and published by . This book was released on 1988 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Forward Flight Effects on Broadband Shock Associated Noise of Supersonic Jets written by Christopher K.W. Tam and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Technical Paper written by United States. National Aeronautics and Space Administration and published by . This book was released on 1988 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Technical Paper written by and published by . This book was released on 1984 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aeroacoustics of Flight Vehicles written by Harvey H. Hubbard and published by . This book was released on 1991 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Shock Structure and Noise of Supersonic Jets in Simulated Flight to Mach 0 4 written by Thomas D. Norum and published by . This book was released on 1988 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Predictions of Supersonic Jet Mixing and Shock Associated Noise Compared with Measured Far Field Data written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-22 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: Codes for predicting supersonic jet mixing and broadband shock-associated noise were assessed using a database containing noise measurements of a jet issuing from a convergent nozzle. Two types of codes were used to make predictions. Fast running codes containing empirical models were used to compute both the mixing noise component and the shock-associated noise component of the jet noise spectrum. One Reynolds-averaged, Navier-Stokes-based code was used to compute only the shock-associated noise. To enable the comparisons of the predicted component spectra with data, the measured total jet noise spectra were separated into mixing noise and shock-associated noise components. Comparisons were made for 1/3-octave spectra and some power spectral densities using data from jets operating at 24 conditions covering essentially 6 fully expanded Mach numbers with 4 total temperature ratios. Dahl, Milo D. Glenn Research Center JET MIXING FLOW; JET AIRCRAFT NOISE; SUPERSONIC JET FLOW; AERODYNAMIC NOISE; NOISE MEASUREMENT; NOISE SPECTRA; FLUID JETS; MACH NUMBER; PREDICTIONS; SHOCK WAVES; TEMPERATURE RATIO

Download or read book Computation of Supersonic Jet Noise Under Imperfectly Expanded Conditions written by Chan M. Kim and published by . This book was released on 1993 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Broadband Shock Associated Noise of Supersonic Jets Measured by a Ground Observer written by Christopher K. W. Tam and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comparison of Flyover Noise Data From Aircraft at High Subsonic Speeds with Prediction written by J. Boettcher and published by . This book was released on 1992 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flyover noise measurements are evaluated for four different military jet aircraft types flying at low altitudes. Flight Mach numbers ranged from 0.5 to 0.9. The analysis shows that noise immission is caused by jet mixing and broadband shock associated noise. Based on the experimental results existing noise prediction schemes are extended toward higher subsonic flight Mach numbers. The novel prediction schemes describe the observed acoustic signatures quite accurately. This holds for the overall sound pressure level in dependence of the emission angle, for sound-pressure level time histories and for one-third-octave spectra.

Download or read book AIAA Journal written by American Institute of Aeronautics and Astronautics and published by . This book was released on 2001 with total page 650 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Prediction of Jet Noise in Flight from Static Tests written by C. L. Morfey and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: