Wind-Tunnel Tests on a Model of a Semisubmersible Platform and Comparison of the Results With Full-Scale Data

1982 ◽  
Author(s):  
H. Boonstra ◽  
C. Leynse
Keyword(s):  
Wind Tunnel ◽  
Full Scale ◽  
Wind Tunnel Tests ◽  
Comparison Of The Results ◽  
Scale Data

Wind tunnel tests on flow fields of full-scale railway wind barriers

2017 ◽  
Vol 24 (2) ◽  
pp. 171-184 ◽  
Author(s):  
Yang Su ◽  
Huoyue Xiang ◽  
Chen Fang ◽  
Lei Wang ◽  
Yongle Li
Keyword(s):  
Wind Tunnel ◽  
Flow Fields ◽  
Full Scale ◽  
Wind Tunnel Tests

scholarly journals Aerodynamic study of a suspension bridge deck by CFD simulations, wind tunnel tests and full-scale observations

2021 ◽  
Vol 1201 (1) ◽  
pp. 012007
Author(s):  
I. Kusano ◽  
E. Cheynet ◽  
J. B. Jakobsen ◽  
J. Snæbjörnsson
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Suspension Bridge ◽  
Aerodynamic Characteristics ◽  
Full Scale ◽  
Navier Stokes ◽  
Cfd Simulations ◽  
Wind Tunnel Tests ◽  
Long Span Bridges ◽  
Wide Range

Abstract Assessing the aerodynamic characteristics of long-span bridges is fundamental for their design. Depending on the terrain complexity and local wind conditions, episodes of large angles of attack (AoA) of 15° may be observed. However, such large AoAs ( above 10°) are often overlooked in the design process. This paper studies the aerodynamics properties of a flow around a single-box girder for a wide range of AoAs, from –20° to 20°, using numerical simulations. The simulations are based on a 2D unsteady Reynolds-averaged Navier–Stokes (URANS) approach using the k − ω SST turbulence model with a Reynolds number of 1.6 × 105. Numerically obtained aerodynamic static coefficients were compared to wind tunnel test data. The CFD results were generally in good agreement with the wind tunnel tests, especially for small AoAs and positive AoAs. More discrepancies were observed for large negative AoA, likely due to the limitation of modelling 3D railings with 2D simulations. The simulated velocity deficit downstream of the deck was consistent with the one measured in full-scale using short-range Doppler wind lidar instruments. Finally, the Strouhal number from the CFD simulations were in agreement with the value obtained from the full-scale data.

Wind-induced response of light and slender arched structures in twin arrangement: Wind tunnel tests and full-scale monitoring

2019 ◽  
Vol 190 ◽  
pp. 262-275 ◽  
Author(s):  
Sara Muggiasca ◽  
Ilmas Bayati ◽  
Stefano Giappino ◽  
Lorenzo Rosa ◽  
Marco Belloli
Keyword(s):  
Wind Tunnel ◽  
Full Scale ◽  
Induced Response ◽  
Wind Tunnel Tests

Current Forces on Prelude Hull and Water Intake Riser by CFD: Full Scale Model Using Two of the World’s Largest Supercomputers

2021 ◽  
Author(s):  
Erwan Auburtin ◽  
Jang Kim ◽  
Hyunchul Jang ◽  
Lawrence Lai ◽  
Jason McConochie ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Wind Tunnel ◽  
Water Intake ◽  
Full Scale ◽  
Scale Model ◽  
Accurate Estimation ◽  
Correct Prediction ◽  
Wind Tunnel Tests ◽  
Numerical Predictions

Abstract The Prelude Floating Liquefied Natural Gas (FLNG) facility is moored with an internal turret allowing it to perform offloading operations of liquefied natural and petroleum gas products. It does so in either a Free Weathervaning (FW) mode, i.e. by allowing the unit to rotate according to environmental loads, or in a Thruster-Assisted (TA) mode, i.e. by using the stern thrusters to maintain a fixed heading deemed preferable for the entire operation, or a particular phase. An accurate estimation of the various environment effects, in terms of forces on the FLNG and LNG carrier, is critical to ensure a correct prediction of its heading or the required thruster forces, depending on the selected operating mode. The predominant loads driving the weathervaning behavior are wind and current loads. These loads have been estimated from wind tunnel tests during the engineering phase. Since the Prelude FLNG has been installed on-site, field measurements have provided an opportunity for comparison and shown some differences with the numerical predictions based on the estimated loads, prompting a need for verification of current loads by an independent method. For the Prelude FLNG application, current loads play an important role due to facility size and significant tidal currents. It has been shown in some previous studies that wind tunnel tests for a model of under-water geometry may underestimate current loads compared to those on a full-scale vessel. There is a boundary layer along the wind tunnel floor in wind tunnel tests, while the current profile is relatively uniform over the hull draft in the real ocean condition. Moreover experimental tests present some additional drawbacks: they are performed at a reduced scale (1:225), the Reynolds number is lower than full-scale even with a large wind tunnel speed, and it is difficult to model the long (150m full-scale) Water Intake Risers (WIR) extending below the hull bottom. In order to investigate these effects, state-of-the-art full-scale CFD simulations were performed for the Prelude hull and WIR. The test program included different current speeds and directions, and several sensitivity studies: Reynolds number effect between model- and full-scales, effect of current speed profile (comparing uniform and boundary layer profiles at model scale), effect of FLNG rotation in yaw, impact of unsteady current, and presence of marine growth. Extreme dimensions of Prelude FLNG and requirements for accuracy of this study called for the CFD calculations to be performed on the High Performance Computing (HPC) clusters - Stampede2 and Frontera - at the Texas Advanced Computing Center (TACC), which are both amongst the world’s largest supercomputers. This paper describes the assumptions and challenges of the CFD study and discusses the results of the main program and various sensitivities. The main conclusions and lessons learnt are also discussed.

Enhanced Wind Tunnel and Full-Scale Sail Force Comparison

2007 ◽  
Author(s):  
Heikki Hansen ◽  
Peter J. Richards ◽  
Peter S. Jackson
Keyword(s):  
Wind Tunnel ◽  
Quantitative Agreement ◽  
Full Scale ◽  
Force Balance ◽  
Testing Procedures ◽  
Prediction Program ◽  
Surface Pressure Distribution ◽  
Velocity Prediction ◽  
The University ◽  
Scale Data

This paper presents a comparison between wind tunnel and full-scale aerodynamic sail force measurements using enhanced wind tunnel testing techniques to model the full-scale sailing conditions more accurately. The first comparison was conducted by Hansen et al., 2003a, in the Twisted Flow Wind Tunnel (TFWT) at The University of Auckland and followed standard testing procedures. Since then enhancements have been made and two aspects not considered in the original comparison are highlighted here. The interaction of the hull and sail forces is now considered and trim changes of the sails due to wind strength are included. For the enhanced comparison the interaction between the hull/deck and the sails is investigated by installing a secondary force balance inside the model to measure the hull/deck forces and by pressure tapping the hull/deck to determine the surface pressure distribution. It is found that the presence of the sails significantly affects the forces on hull/deck when sailing upwind, which should be accounted for consistently in comparisons of full-scale, wind tunnel, and computational fluid dynamics (CFD) data. In the original comparison the sails were trimmed in the wind tunnel to the aerodynamically optimal shape by maximizing the drive force. Trim variations due to wind strength were however noted in full-scale data so that depowering is considered in the enhanced comparison. The sails in the wind tunnel were trimmed based on the fullscale wind strength and the yacht performance by employing a Real-Time Velocity Prediction Program (VPP) to achieve realistically depowered sail shapes. Utilising the enhanced wind tunnel techniques a generally good qualitative and quantitative agreement with the full-scale data was achieved, but a conclusive judgment of the accuracy of the comparison cannot be made.

Aeroacoustic of the VEGA Launcher: Wind Tunnel Tests and Full Scale Extrapolations

2005 ◽  
Author(s):  
Biagio Imperatore ◽  
Giulio Guj ◽  
Antonio Ragni ◽  
Antonio Pizzicaroli ◽  
Emanuele Giulietti
Keyword(s):  
Wind Tunnel ◽  
Full Scale ◽  
Wind Tunnel Tests

Analysis of Rear Window Buffeting Characteristics Using a Production Sedan

2012 ◽  
Vol 220-223 ◽  
pp. 771-774
Author(s):  
Yin Zhi He ◽  
Zhi Gang Yang
Keyword(s):  
Wind Tunnel ◽  
Resonance Peak ◽  
Full Scale ◽  
Rear Window ◽  
Side Window ◽  
Wind Tunnel Tests ◽  
Window Opening ◽  
Yaw Angle

In this paper rear left side window buffeting characteristics of a production sedan under different yaw angles and different window opening sizes are investigated through full-scale aeroacoustic wind tunnel tests. By yaw angle -10 degree, as driver position on the lee side, the resonance peak SPL is much less than that by yaw angle 0 or +10 degree and the corresponding frequency is also some lower than that by yaw angle 0 or +10 degree. As window opening size turns small, the resonance peak SPL decreases. By side window with 25% opening size, the peak SPL is much less than that by side window with 50% or 100% opening size. In addition, the corresponding frequency is also some lower than that by side window with 50% or 100% opening size. Different test positions at the front row or back row show very similar buffeting characteristics.

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