Author: J. H. Watmuff
Publisher:
ISBN:
Category :
Languages : en
Pages : 21
Book Description
Design of a New Contraction for the ARL Low Speed Wind Tunnel
Author: J. H. Watmuff
Publisher:
ISBN:
Category :
Languages : en
Pages : 21
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 21
Book Description
Design of a New Contraction for the ARL (Aeronautical Research Laboratories) Low Speed Wind Tunnel
Author: Jonathan H. Watmuff
Publisher:
ISBN:
Category :
Languages : en
Pages : 45
Book Description
A numerical method is developed for the solution of Stoke's Streamfunction. The method is applied to the exisiting Low Speed Wind Tunnel (LSWT) contraction shape. The calculated wall pressure coefficient distribution is compared to experimental measurements to test the approximation of axial symmetry made for the octagonal sections and for the effects of neglecting viscous forces. Reasonable agreement is obtained. The existing contraction is known to suffer from intermittent boundary layer separation near the entry caused by adverse pressure gradients. A new contraction shape is suggested that uses the contraction ratio of the existing LSWT so that the new design can be installed within the existing LSWT in the form of an inner skin. The new design, which is about 10% longer than the existing contraction, has an adverse pressure gradient near the inlet which is about 1/5 of that of the existing contraction while the adverse pressure gradient near the exit is around the same value. Keywords: Wind tunnel nozzles, Subsonic wind tunnels, Flow distribution, Australia. (MJM).
Publisher:
ISBN:
Category :
Languages : en
Pages : 45
Book Description
A numerical method is developed for the solution of Stoke's Streamfunction. The method is applied to the exisiting Low Speed Wind Tunnel (LSWT) contraction shape. The calculated wall pressure coefficient distribution is compared to experimental measurements to test the approximation of axial symmetry made for the octagonal sections and for the effects of neglecting viscous forces. Reasonable agreement is obtained. The existing contraction is known to suffer from intermittent boundary layer separation near the entry caused by adverse pressure gradients. A new contraction shape is suggested that uses the contraction ratio of the existing LSWT so that the new design can be installed within the existing LSWT in the form of an inner skin. The new design, which is about 10% longer than the existing contraction, has an adverse pressure gradient near the inlet which is about 1/5 of that of the existing contraction while the adverse pressure gradient near the exit is around the same value. Keywords: Wind tunnel nozzles, Subsonic wind tunnels, Flow distribution, Australia. (MJM).
Design of a New Contraction, Wide Angle Diffuser and Flow Manipulators for the Low Speed Wind Tunnel
Author: John Burnett Willis
Publisher:
ISBN: 9780642879493
Category : Wind tunnels
Languages : en
Pages : 12
Book Description
It is over forty years since the A.R.L. low speed wind tunnel was built, and the quality of the flow in the test section is inadequate by today's standards. This memorandum describes the design of a new contraction, wide angle diffuser and flow manipulators, to improve the flow in this tunnel. These modifications should substantially improve the velocity distribution and reduce turbulence levels with only a small reduction in top speed of the tunnel. A useful increase in the length of the test section has also been obtained. (Author).
Publisher:
ISBN: 9780642879493
Category : Wind tunnels
Languages : en
Pages : 12
Book Description
It is over forty years since the A.R.L. low speed wind tunnel was built, and the quality of the flow in the test section is inadequate by today's standards. This memorandum describes the design of a new contraction, wide angle diffuser and flow manipulators, to improve the flow in this tunnel. These modifications should substantially improve the velocity distribution and reduce turbulence levels with only a small reduction in top speed of the tunnel. A useful increase in the length of the test section has also been obtained. (Author).
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 956
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 956
Book Description
Technical Reports Awareness Circular : TRAC.
Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 516
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 516
Book Description
Contraction Design for Small Low-Speed Wind Tunnels
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722129330
Category :
Languages : en
Pages : 40
Book Description
An iterative design procedure was developed for two- or three-dimensional contractions installed on small, low-speed wind tunnels. The procedure consists of first computing the potential flow field and hence the pressure distributions along the walls of a contraction of given size and shape using a three-dimensional numerical panel method. The pressure or velocity distributions are then fed into two-dimensional boundary layer codes to predict the behavior of the boundary layers along the walls. For small, low-speed contractions it is shown that the assumption of a laminar boundary layer originating from stagnation conditions at the contraction entry and remaining laminar throughout passage through the successful designs if justified. This hypothesis was confirmed by comparing the predicted boundary layer data at the contraction exit with measured data in existing wind tunnels. The measured boundary layer momentum thicknesses at the exit of four existing contractions, two of which were 3-D, were found to lie within 10 percent of the predicted values, with the predicted values generally lower. From the contraction wall shapes investigated, the one based on a fifth-order polynomial was selected for installation on a newly designed mixing layer wind tunnel. Bell, James H. and Mehta, Rabindra D. Unspecified Center NCC2-294; RTOP 505-60-31...
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722129330
Category :
Languages : en
Pages : 40
Book Description
An iterative design procedure was developed for two- or three-dimensional contractions installed on small, low-speed wind tunnels. The procedure consists of first computing the potential flow field and hence the pressure distributions along the walls of a contraction of given size and shape using a three-dimensional numerical panel method. The pressure or velocity distributions are then fed into two-dimensional boundary layer codes to predict the behavior of the boundary layers along the walls. For small, low-speed contractions it is shown that the assumption of a laminar boundary layer originating from stagnation conditions at the contraction entry and remaining laminar throughout passage through the successful designs if justified. This hypothesis was confirmed by comparing the predicted boundary layer data at the contraction exit with measured data in existing wind tunnels. The measured boundary layer momentum thicknesses at the exit of four existing contractions, two of which were 3-D, were found to lie within 10 percent of the predicted values, with the predicted values generally lower. From the contraction wall shapes investigated, the one based on a fifth-order polynomial was selected for installation on a newly designed mixing layer wind tunnel. Bell, James H. and Mehta, Rabindra D. Unspecified Center NCC2-294; RTOP 505-60-31...
Contraction Design for Small Low-speed Wind Tunnels
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 44
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 44
Book Description
Aeronautical Engineering
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1112
Book Description
A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA).
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1112
Book Description
A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA).
Government Reports Annual Index
Author:
Publisher:
ISBN:
Category : Government reports announcements & index
Languages : en
Pages : 1182
Book Description
Publisher:
ISBN:
Category : Government reports announcements & index
Languages : en
Pages : 1182
Book Description
Technical Abstract Bulletin
Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 190
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 190
Book Description