Suppression of Refraction in Jet Noise by Cooling 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 Suppression of Refraction in Jet Noise by Cooling PDF full book. Access full book title Suppression of Refraction in Jet Noise by Cooling by J. T. Kelsall. Download full books in PDF and EPUB format.
Author: J. T. Kelsall
Publisher:
ISBN:
Category : Aerodynamic noise
Languages : en
Pages : 23
Get Book Here
Book Description
Noise generation in an air jet can be described in terms of a convection factor. The velocity gradients in the flow refract the sound, giving rise to a commonly observed final directivity. In the experiments outlined here the effects of convection and refraction on directivity are examined for a jet of very cold air. An attempt is made to determine whether any interdependence between convection and refraction can be detected experimentally in narrow band jet noise data. In the reported investigation liquid nitrogen was used to cool a jet of air (at nozzle speeds 0.21 to 0.28 of ambient sound speed) down to temperatures (between -110C and -155C) at which the refraction from the opposed velocity and temperature gradients produced cancellation effects.
Author: J. T. Kelsall
Publisher:
ISBN:
Category : Aerodynamic noise
Languages : en
Pages : 23
Get Book Here
Book Description
Noise generation in an air jet can be described in terms of a convection factor. The velocity gradients in the flow refract the sound, giving rise to a commonly observed final directivity. In the experiments outlined here the effects of convection and refraction on directivity are examined for a jet of very cold air. An attempt is made to determine whether any interdependence between convection and refraction can be detected experimentally in narrow band jet noise data. In the reported investigation liquid nitrogen was used to cool a jet of air (at nozzle speeds 0.21 to 0.28 of ambient sound speed) down to temperatures (between -110C and -155C) at which the refraction from the opposed velocity and temperature gradients produced cancellation effects.
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 36
Get Book Here
Book Description
Author: R. E. Ballard
Publisher:
ISBN:
Category :
Languages : en
Pages : 125
Get Book Here
Book Description
The proven Coanda/refraction concept is applied to the Navy requirement for effective exhaust noise suppression of aircraft (installed engines) ground run up tests. The technical approach is comprised of analytic studies and one-sixth scale model tests using simulated sources for single and twin-engine aircraft. The results of previous exploratory studies, using simulated static sources, are applied to the more complex situation with the engine tailpipe centerline displaced horizontally, vertically, longitudinally and angularly from the model suppressor inlet. Test runs at varied simulated engine power settings and varied model geometric orientations were conducted to determine the effects on jet attachment to the Coanda surface and on cooling air eduction. The extensive recorded test data were analyzed to identify aero/ thermodynamic trends related to suppressor internal components, ejector geometry and material cooling properties. Results present operational limits and configurations for further development as exhaust systems for aircraft test enclosures and aircraft run up suppressors.
Author: R. E. Ballard
Publisher:
ISBN:
Category :
Languages : en
Pages : 91
Get Book Here
Book Description
The successfully demonstrated Coanda/refraction air-cooled exhaust noise suppressor system is applied to the Navy requirement for effective exhaust noise suppression in jet engine demountable test cells. The technical approach consists of analytical studies and one-sixth scale model tests using simulated afterburning engine exhaust. Revisions are made to the previously developed system to improve noise suppression capability while reducing the system overall size and initial cost. Revisions include moving secondary air inlets to reduce enclosure size and improve cooling, shortening the Coanda surface to provide more acoustically treated exhaust stack and providing variations in exhaust stack configuration such as single and dual acoustic splitters and acoustic wedges up the back wall. Extensive data were recorded and analyzed to identify the aerothermodynamic and acoustic trends related to these configuration changes. Results present recommendations for an air-cooled Coanda/refraction exhaust system for application to demountable test cells. (Author).
Author: R. E. Ballard
Publisher:
ISBN:
Category :
Languages : en
Pages : 89
Get Book Here
Book Description
The successfully demonstrated Coanda/refraction air-cooled exhaust noise suppressor system is applied to the Navy requirement for an effective air-cooled retrofit configuration for the class 'C' test cells (concrete enclosure). The technical approach consists of analytically sizing retrofit components to meet both acoustic ad aerothermodynamic requirements and then testing at one-sixth scale using simulated afterburning engine exhaust to verify the design configuration. Model variations included exhaust stack height, exhaust stack inner flow passage configurations (straight walls and diffuser) and removal of a concrete internal partition wall. Extensive data were recorded and analyzed to identify the aerothermodynamic trends related to these configuration changes. Results present recommendations for an air-cooled Coanda exhaust noise suppression system for retrofit of Navy class 'C' test cells. (Author).
Author: Technology Reports Centre (Great Britain)
Publisher:
ISBN:
Category :
Languages : en
Pages : 460
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 892
Get Book Here
Book Description
Author: Wade H. Shafer
Publisher: Springer Science & Business Media
ISBN: 1475757824
Category : Science
Languages : en
Pages : 304
Get Book Here
Book Description
Masters Theses in the Pure and Applied Sciences was first conceived, published, and dis seminated by the Center for lnformation and Numerica/ Data Analysis and Synthesis (C/NDAS) * at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the ac tivity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficia! to the academic and general scientific and technical community. After fi ve years of this joint undertaking we had concluded that it was in the interest of ali concerned if the printing and distribution of the volume were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and App/ied Sciences has been disseminated on a worldwide basis by Plenum Publishing Corporation of New York, and in the same year the coverage was broadened to include Canadian universities. Ali back issues can also be ordered from Plenum. We have reported in Volume 21 (thesis year 1976) a total of 10,586 theses titles from 25 Canadian and 219 United States universities. We are sure that this broader base for theses titles reported will greatly enhance the value of this important annual reference work.
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 700
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 408
Get Book Here
Book Description
