Air flow quality analysis of an open-circuit boundary layer wind tunnel and comparison with a closed-circuit wind tunnel

2020 ◽  
Vol 32 (12) ◽  
pp. 125120
Author(s):  
María Jiménez-Portaz ◽  
Luca Chiapponi ◽  
María Clavero ◽  
Miguel A. Losada
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Air Flow ◽  
Open Circuit ◽  
Closed Circuit ◽  
Quality Analysis ◽  
Flow Quality

WIND PRESSURE DISTRIBUTION ON LOW-RISE BUILDINGS WITH CYLINDRICAL ROOFS

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Astha Verma ◽  
Ashok Kumar Ahuja
Keyword(s):  
Boundary Layer ◽  
Experimental Study ◽  
Wind Tunnel ◽  
Pressure Distribution ◽  
Open Circuit ◽  
Wind Pressure ◽  
Wind Loads ◽  
Wind Loading ◽  
Pressure Coefficients ◽  
Available Information

Wind is one of the important loads to be considered while designing the roofs of low-rise buildings. The structural designers refer to relevant code of practices of various countries dealing with wind loads while designing building roofs. However, available information regarding wind pressure coefficients on cylindrical roofs is limited to single span only. Information about wind pressure coefficients on multi-span cylindrical roofs is not available in standards on wind loads. Present paper describes the details of the experimental study carried out on the models of low-rise buildings with multi-span cylindrical roofs in an open circuit boundary layer wind tunnel. Wind pressure values are measured at many pressure points made on roof surface of the rigid models under varying wind incidence angles. Two cases namely, single-span and two-span are considered. The experimental results are presented in the form of contours of mean wind pressure coefficients. Results presented in the paper are of great use for the structural designers while designing buildings with cylindrical roofs. These values can also be used by the experts responsible for revising wind loading codes from time to time.

Development of the Reattached Flow Behind Surface-Mounted Two-Dimensional Prisms

1988 ◽  
Vol 110 (2) ◽  
pp. 127-133 ◽  
Author(s):  
J. Antoniou ◽  
G. Bergeles
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Open Circuit ◽  
Two Dimensional ◽  
Blow Down ◽  
Length Scales ◽  
Turbulent Eddies ◽  
Flow Parameters ◽  
Varying Length ◽  
Dimensional Surface

Velocity and turbulence measurements are presented for the region after reattachment behind a two dimensional surface-mounted prism of varying length. The prism is mounted on the floor of an open circuit blow down wind tunnel and flow parameters for the developing boundary layer are deduced from the measurements; longitudinal integral time and length scales are estimated through autocorrelations. Reattchment on top of the prism, due to its increased length, affects the characteristics of the developing boundary layer; in this case the shear layer originating from the up-stream edge of the prism splits twice at reattachment points on top and behind the prism and the integral length scales of the turbulent eddies are found to be smaller due to the splitting.

Air flow quality analysis in optimizing MODENAS GT128 engine performance

2021 ◽  
Author(s):  
M. T. A. Rahman ◽  
A. Rahman ◽  
N. S. Ahmat ◽  
G. E. Suhri
Keyword(s):  
Air Flow ◽  
Engine Performance ◽  
Quality Analysis ◽  
Flow Quality

scholarly journals Airfoil profile optimization of an air suction equipment with an air duct

2015 ◽  
Vol 19 (4) ◽  
pp. 1217-1222 ◽  
Author(s):  
Li Qiu ◽  
Rui Wang ◽  
Xiao-Dong Chen ◽  
De-Peng Wang
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Critical Angle ◽  
Air Flow ◽  
Operation Mode ◽  
Wind Tunnel Test ◽  
Flow Fields ◽  
External Flow ◽  
Air Speed ◽  
Profile Optimization

On the basis of boundary layer with the airfoil profile, this research attempts to investigate the effect of the angle of spread of the winged air suction equipment on the efficiency of operation. The application of Fluent with the split-middle method under the identical operation mode is expected to optimize the spread angle. The investigated airfoil profile is NACA6413, of which the restrictions on the critical angle of spread suggested in literature will be overcome through the interactions between the internal and external flow fields. As a result, the air speed might increase. The wind tunnel test employed in this research offers the solid evidences to support this hypothesis. The test demonstrates that when the angle of spread is larger than 12?, the effect of accelerating the air flow is still observable. Following the optimization, the air suction effect of the equipment would be optimal when its angle of spread reached 30?.

A Small Wind Tunnel Significantly Improved by a Multi-Purpose, Two-Flexible-Wall Test Section

1994 ◽  
Vol 116 (3) ◽  
pp. 419-423 ◽  
Author(s):  
P. Kankainen ◽  
E. Brundrett ◽  
J. A. Kaiser
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Test Section ◽  
Side Wall ◽  
Reynolds Numbers ◽  
Free Data ◽  
Wall Panels ◽  
Testing Data ◽  
Flexible Wall ◽  
Flow Quality

A small open-return wind tunnel has been renovated to include a longer test section with a flexible roof and floor and improved entrance flow quality. The flexible-wall test section allows models with up to 30 percent nominal blockage to be tested, resulting in a significant increase in the maximum attainable Reynolds numbers. Interchangeable rigid side-wall panels allow flexibility of application which is essential for a university wind tunnel facility. Configurations have been developed for automotive, aerodynamic and atmospheric-boundary-layer testing. Data acquisition and wall positioning are at an economical semi-automated level of operation. The flexible-wall concept has been well-documented previously, and provides interference-free data without flow pattern assumptions after a few iterations of the roof and floor shape. Representative data are presented for a circular cylinder and an airfoil.

Design of the Inlet for an Open Circuit Wind Tunnel for Testing Full Scale Class Eight Trucks

Volume 1 ◽  
2004 ◽  
Author(s):  
Bhaskar Bhatnagar ◽  
Gerald Recktenwald
Keyword(s):  
Boundary Layer ◽  
Velocity Field ◽  
Wind Tunnel ◽  
Velocity Profile ◽  
Open Circuit ◽  
Full Scale ◽  
Boundary Layer Analysis ◽  
Velocity Magnitude ◽  
Layer Analysis ◽  
Axial Profile

A commercial CFD program and boundary layer analysis are used to design the inlet of an open circuit wind tunnel for aerodynamic testing of full scale, class eight trucks. The goal of the study is to obtain the combination of wall shape, contraction length, and setting screens that provide a uniform velocity profile upstream of the vehicle under test. Thwaites method is used to verify that the boundary layer does not separate. Velocity field predictions upstream of the vehicle under test are presented for different design configurations of the inlet. A variation in the velocity magnitude of less than one percent outside of the boundary layer is achievable. The contraction introduces a weak secondary flow in the corners of the wind tunnel, but the cross stream components do not lead to significant distortion of the axial profile.

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