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?.

scholarly journals Aerodynamic Analysis on Proton Preve by Experimental

2015 ◽  
Vol 773-774 ◽  
pp. 575-579
Author(s):  
Mohamad Nor Musa ◽  
Samion Syahrullail ◽  
Fairuz Zainal Abidin
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Wind Tunnel ◽  
Shape Optimization ◽  
Air Flow ◽  
Literature Reviews ◽  
Air Speed ◽  
Vehicle Shape ◽  
Low Speed Wind Tunnel ◽  
The Relationship

The purpose of this study is to determine the coefficient drag, CD of the Proton PREVẾ by experimental method using Low Speed Wind Tunnel. All the relevant data are collected through the literature reviews from books and journals. First, the basic thing in aerodynamic is studied. There are two things are concern when studies aerodynamics. They were air flow and vehicle shape which we regard as aerodynamics factor that determine aerodynamic of the vehicle. Fundamental of air flow and vehicle shape is reviewed includes the relationship between air speed with pressure, boundary layer, Reynolds number, drag, lift drag and shape optimization. Wind tunnel is also studied before the experiment. Five selected speed were been tasted during the experiment to determine the CD value.

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

Evaluation of Wind Loads on FPSO Topsides Using a Numerical Wind Tunnel

2016 ◽  
Author(s):  
Daniel Barcarolo ◽  
Yann Andrillon ◽  
Erwan Jacquin ◽  
Alain Ledoux
Keyword(s):  
Boundary Layer ◽  
Numerical Model ◽  
Wind Tunnel ◽  
Atmospheric Boundary Layer ◽  
Scale Effects ◽  
Geometric Model ◽  
Wind Tunnel Test ◽  
Offshore Structures ◽  
Wind Loads ◽  
The Impact

The accurate evaluation of wind loads applied on floating offshore structures is extremely important as they are in specific conditions one of the dimensioning criteria for the mooring design. Nowadays these loads are mainly assessed through wind tunnel tests performed at model scale. Estimating realistic wind loads however, remains a big challenge. The complexity and associated simplification level of FPSO topside structures, the scale effects and the establishment of the atmospheric boundary layer imply that many simplifications are to be made. Typically, the FPSO topside is greatly simplified and equivalent blocs of wired frame are used. Today with the evolution of CFD software, and the increase of the meshing capacity, new scopes open to CFD. Aerodynamic simulations on complex FPSO structures are therefore now possible, but need specific developments and validations that are presented in this paper. The main objective of the work presented is to investigate the ability of CFD to evaluate wind loads on complex FPSOs topsides and to provide information on the impact of model simplifications made in wind tunnels. In a first stage, the numerical model was intensively validated by comparing its results to a wind tunnel test case. The numerical model was developed in order to ensure the quality of the results and enable a relevant comparison that was obtained with grids density up to 30 million cells. For this purpose, the geometric model used corresponds to the one used in wind tunnel. The same Atmospheric Boundary Layer was simulated and a thorough effort was performed to ensure the mesh convergence. In a second stage, more physical aspects of the wind tunnel methodology were investigated. Typically the accuracy of the blockage effect correction was evaluated by performing computations with and without blockage, and results were compared with classical corrections applied in wind tunnel. The impacts of the Atmospheric Boundary Layer on wind loads have also been investigated. Finally, the wind load contribution of each component of the FPSO was evaluated.

Current Drag From Tow and Wind Tunnel Tests of a FLNG Hull

2016 ◽  
Author(s):  
Zhenjia (Jerry) Huang ◽  
Jang Kim ◽  
Hyunchul Jang ◽  
Scott T. Slocum
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Model Test ◽  
Cfd Simulation ◽  
Wind Tunnel Test ◽  
Model Tests ◽  
Additional Contribution ◽  
Wind Tunnel Model ◽  
Tunnel Model ◽  
Current Drag

In this paper, the current drag of a barge-shaped floating liquefied natural gas (FLNG) vessel was studied. Three model tests were performed — a wind tunnel model test, a submerged double-body tow test and a surface tow test. Computational fluid dynamics (CFD) simulations were carried out to gain further insights into the test results. During testing, the tow speed was kept low to avoid surface waves. When the current heading was around the beam current direction, the transverse drag coefficient measured from the wind tunnel test was significantly lower than those of the submerged tow and surface tow tests. The submerged tow and the surface tow provided similar drag coefficients. Results presented in this paper indicated that the difference between the wind tunnel test and the tow tests was caused by the wind tunnel boundary layer effect on the incoming wind profile and formation of a recirculation zone on the upstream side of the model, with a possible additional contribution from the wind tunnel floor constraint on the flow in the wake. Such effects are not accounted for with the simple corrections based on flow velocity reduction in the wind tunnel boundary layer. When conducting future wind tunnel model tests for barge-shaped FLNG hulls, one should consider the potential under-measurement of the transverse drag. In this paper, details of the FLNG model, test setup, test quality assurance (QA), measurement and CFD simulation results are presented, as well as discussions and recommendations for model testing.

scholarly journals Experimental and Computational Analysis of Model–Support Interference in Low-Speed Wind-Tunnel Testing of Fuselage-Boundary-Layer Ingestion

2019 ◽  
Vol 304 ◽  
pp. 02020
Author(s):  
Biagio Della Corte ◽  
André A.V. Perpignan ◽  
Martijn van Sluis ◽  
Arvind Gangoli Rao
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Leading Edge ◽  
Horseshoe Vortex ◽  
Junction Flow ◽  
Tunnel Model ◽  
Aerodynamic Interaction ◽  
Support Interference ◽  
Model Support

Junction flow caused by the aerodynamic interaction between a wind-tunnel model and the support structure can largely influence the flowfield and hence the experimental results. This paper discusses a combined numerical and experimental study which was carried out to mitigate the model–support interference in a wind-tunnel test setup for the study of fuselage boundary-layer ingestion. The setup featured an axisymmetric fuselage mounted through a support beam, covered by a wing-shaped fairing. The junction flow appearing at the fuselage–fairing connection produced undesired flow distortions at the fuselage aft section, due to the formation of an horseshoe vortex structure at the fairing leading edge. Numerical and experimental analysis were performed with the aim of reducing the distortion intensity by improving the fairing design. Results show that modifying the leading-edge shape of the fairing effectively decreased the flowfield distortions. Moreover, the addition of a dummy fairing diametrically opposed to the first one was found to be beneficial due to the enhancement of the configuration symmetry.

Large Scale Pressurized Water Reactor Passive Containment Cooling System Wind Tunnel Test

2019 ◽  
Vol 5 (3) ◽  
Author(s):  
Huang Jingyu ◽  
Pan Xinxin ◽  
Song Chunjing
Keyword(s):  
Wind Tunnel ◽  
Large Scale ◽  
Cooling System ◽  
Air Flow ◽  
Wind Tunnel Test ◽  
Pressurized Water Reactor ◽  
Scaled Model ◽  
Pressurized Water ◽  
Water Reactor ◽  
Wind Speeds

The objective of the current work is to shed light on studying the air flow features of the air path which is part of the passive containment cooling system (PCS) in a pressurized water reactor design. A wind tunnel test using a 1:100 scaled model is established to study the characteristic called “wind-neutrality” of the air flow in the air path, which indicates that the environmental wind should not be beneficial or detrimental to the air flow for containment cooling. Test results show that the pressure distribution in the air path is uniform, and wind speeds, wind angles, and surroundings have little effect on air flow uniformity. These investigations show that it is possible to understand air flows in the air path of PCS with a scale wind tunnel test.

scholarly journals Validation of a laminar-turbulent transition prediction technique for a swept-wing boundary-layer flow

2021 ◽  
Vol 2057 (1) ◽  
pp. 012081
Author(s):  
A V Boiko ◽  
V I Borodulin ◽  
A V Ivanov ◽  
S V Kirilovskiy ◽  
D A Mischenko ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Test Section ◽  
Wind Tunnel Test ◽  
Cross Flow ◽  
Infrared Camera ◽  
Main Flow ◽  
Swept Wing ◽  
Turbulent Transition ◽  
Laminar Turbulent Transition

Abstract The laminar-turbulent transition in the boundary layer of a 45° swept wing model installed at zero attack angle in the test section of a subsonic wind-tunnel was detected with the help of an infrared camera. The camera recorded sequences of frames, the evolution of the preheated model surface temperature acquired and used for differentiating between the laminar and turbulent regions. The transition onset was evaluated at both sides of the model. Corresponding main flow computations in the virtual wind tunnel test section were performed at the same flow conditions with ANSYS Fluent. The computed main-flow velocity profiles along inviscid streamlines were used for analysis of hydrodynamic stability of the boundary layer with respect to Tollmien-Schlichting waves and stationary cross-flow vortices to obtain N-factor distributions along the model chord. A comparison of the experimental and the computed transition onsets was performed.

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