En Route Noise Levels from Propfan Test Assessment Airplane PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download En Route Noise Levels from Propfan Test Assessment Airplane PDF full book. Access full book title En Route Noise Levels from Propfan Test Assessment Airplane by Donald P. Garber. Download full books in PDF and EPUB format.
Author: Donald P. Garber
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 36
Get Book Here
Book Description
Author: Donald P. Garber
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 36
Get Book Here
Book Description
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722202309
Category :
Languages : en
Pages : 32
Get Book Here
Book Description
The en route noise test was designed to characterize propagation of propfan noise from cruise altitudes to the ground. In-flight measurements of propfan source levels and directional patterns were made by a chase plane flying in formation with the propfan test assessment (PTA) airplane. Ground noise measurements were taken during repeated flights over a distributed microphone array. The microphone array on the ground was used to provide ensemble-averaged estimates of mean flyover noise levels, establish confidence limits for those means, and measure propagation-induced noise variability. Even for identical nominal cruise conditions, peak sound levels for individual overflights varied substantially about the average, particularly when overflights were performed on different days. Large day-to-day variations in peak level measurements appeared to be caused by large day-to-day differences in propagation conditions and tended to obscure small variations arising from operating conditions. A parametric evaluation of the sensitivity of this prediction method to weather measurement and source level uncertainties was also performed. In general, predictions showed good agreement with measurements. However, the method was unable to predict short-term variability of ensemble-averaged data within individual overflights. Although variations in absorption appear to be the dominant factor in variations of peak sound levels recorded on the ground, accurate predictions of those levels require that a complete description of operational conditions be taken into account. The comprehensive and integrated methods presented in this paper have adequately predicted ground-measured sound levels. On average, peak sound levels were predicted within 3 dB for each of the three different cruise conditions. Garber, Donald P. and Willshire, William L., Jr. Langley Research Center RTOP 535-03-11-02...
Author: David A. McCurdy
Publisher:
ISBN:
Category : Aerodynamic noise
Languages : en
Pages : 44
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 884
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 548
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1450
Get Book Here
Book Description
Author: United States. National Aeronautics and Space Administration
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 44
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 878
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Astronautics
Languages : en
Pages : 486
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1100
Get Book Here
Book Description
