Download or read book Background Noise Levels Measured in the NASA Lewis 9 by 15 foot Low speed Wind Tunnel written by Richard P. Woodward and published by . This book was released on 1995 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustical Evaluation of the NASA Lewis 9 by 15 Foot Low Speed Wind Tunnel written by Milo D. Dahl and published by . This book was released on 1992 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Noise Measurements from an Ejector Suppressor Nozzle in the NASA Lewis 9 by 15 foot Low Speed Wind Tunnel written by and published by . This book was released on 1990 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustical Evaluation of the NASA Lewis 9 by 15 Foot Low Speed Wind Tunnel written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-06 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: The test section of the NASA Lewis 9- by 15-Foot Low Speed Wind Tunnel was acoustically treated to allow the measurement of acoustic sources located within the tunnel test section under simulated free field conditions. The treatment was designed for high sound absorption at frequencies above 250 Hz and to withstand tunnel airflow velocities up to 0.2 Mach. Evaluation tests with no tunnel airflow were conducted in the test section to assess the performance of the installed treatment. This performance would not be significantly affected by low speed airflow. Time delay spectrometry tests showed that interference ripples in the incident signal resulting from reflections occurring within the test section average from 1.7 dB to 3.2 dB wide over a 500 to 5150 Hz frequency range. Late reflections, from upstream and downstream of the test section, were found to be insignificant at the microphone measuring points. For acoustic sources with low directivity characteristics, decay with distance measurements in the test section showed that incident free field behavior can be measured on average with an accuracy of +/- 1.5 dB or better at source frequencies from 400 Hz to 10 kHz. The free field variations are typically much smaller with an omnidirectional source. Dahl, Milo D. and Woodward, Richard P. Glenn Research Center...
Download or read book Calibration of the NASA Lewis Research Center 9 by 15 Foot Low Speed Wind Tunnel 1994 Test written by and published by . This book was released on 1997 with total page 190 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 548 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 1978 with total page 372 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 1978 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book STAR written by and published by . This book was released on 1973 with total page 904 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeroacoustic Measurements written by Thomas J. Mueller and published by Springer Science & Business Media. This book was released on 2013-11-27 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book describes recent developments in aeroacoustic measurements in wind tunnels and the interpretation of the resulting data. The reader will find the latest measurement techniques described along with examples of the results.
Download or read book Comparison Between Design and Installed Acoustic Characteristics of NASA Lewis 9 by 15 Foot Low Speed Wind Tunnel Acoustic Treatment written by Milo D. Dahl and published by . This book was released on 1990 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1995 with total page 1632 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1995 with total page 1638 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comparison of the Noise Characteristics of Two Low Pressure Ratio Fans with a High Throat Mach Number Inlet written by Howard L. Wesoky and published by . This book was released on 1978 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 43rd AIAA Aerospace Sciences Meeting Exhibit written by and published by . This book was released on 2005 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sources and Levels of Background Noise in the NASA Ames 40 By 80 Foot Wind Tunnel written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-12 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Background noise levels are measured in the NASA Ames Research Center 40- by 80-Foot Wind Tunnel following installation of a sound-absorbent lining on the test-section walls. Results show that the fan-drive noise dominated the empty test-section background noise at airspeeds below 120 knots. Above 120 knots, the test-section broadband background noise was dominated by wind-induced dipole noise (except at lower harmonics of fan blade-passage tones) most likely generated at the microphone or microphone support strut. Third-octave band and narrow-band spectra are presented for several fan operating conditions and test-section airspeeds. The background noise levels can be reduced by making improvements to the microphone wind screen or support strut. Empirical equations are presented relating variations of fan noise with fan speed or blade-pitch angle. An empirical expression for typical fan noise spectra is also presented. Fan motor electric power consumption is related to the noise generation. Preliminary measurements of sound absorption by the test-section lining indicate that the 152 mm thick lining will adequately absorb test-section model noise at frequencies above 300 Hz. Soderman, Paul T. Ames Research Center RTOP 505-61-11...
Download or read book Fan Noise Source Diagnostic Test Far Field Acoustic Results written by and published by . This book was released on 2002 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
