Comparative Analysis on Aerostatic Coefficients of Bridge Deck Based on Wind Tunnel Test

2010 ◽  
Vol 29-32 ◽  
pp. 377-382
Author(s):  
Fu You Xu ◽  
Bin Bin Li ◽  
Cai Liang Huang ◽  
Zhe Zhang
Keyword(s):  
Comparative Analysis ◽  
Wind Tunnel ◽  
Working Conditions ◽  
Turbulence Intensity ◽  
Flow Separation ◽  
Bridge Deck ◽  
Force Measurement ◽  
Wind Tunnel Test ◽  
Microscopic Mechanism ◽  
Comprehensive Study

A comprehensive study of force measurement test in wind tunnel is conducted for the streamlined deck model of Dalian Cross-sea Bridge scheme. The factors, including stacking load in erection, vehicles arrangement, central slot and so on, are analyzed in terms of the influence of the three-component coefficient in the way of microscopic mechanism. The stall angles under different working conditions are also investigated. The results show that stacking loads and vehicle arrangement barely have any impact on the three-component coefficient, which can be neglected approximately; lift and pitching coefficients decrease for the slotted deck, and the slot width has little influence on the aerostatic coefficients; bridge railing, stacking loads and vehicles change the flow separation and re-attachment around the deck, increasing the turbulence intensity, leading to the fluctuation of stall angles.

A Study on the Target 2D Tracking Analysis Using Digital Image Correlation at Bridge Deck Wind Tunnel Test

2012 ◽  
Vol 18 (1) ◽  
pp. 2127-2135
Author(s):  
Seung-Taek Oh ◽  
Nak-Hyun Chun ◽  
Seung-Young Yoo ◽  
Ho-Yeop Lee ◽  
Hak-Eun Lee
Keyword(s):  
Wind Tunnel ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Bridge Deck ◽  
Wind Tunnel Test ◽  
Image Correlation

Wind Tunnel Test of Honeycomb in Improving Flow Quality

2013 ◽  
Vol 774-776 ◽  
pp. 275-278
Author(s):  
Chun Guang Li ◽  
Yang Liu ◽  
John.C.K. Cheung
Keyword(s):  
Wind Tunnel ◽  
Cell Size ◽  
Turbulence Intensity ◽  
Wind Tunnel Test ◽  
Open Loop ◽  
Incoming Flow ◽  
Flow Quality ◽  
The Mean ◽  
Square Cells ◽  
Change Tendency

The function of honeycomb with different length and width in improving flow quality were studied in the course of building a new small section open loop wind tunnel. Instantaneous velocities of turbulent flow in the tunnel were measured by cobra probe. The focus of this study was put on the effect of the honeycomb in attenuating the total turbulence intensity including the free-turbulence carried by the incoming flow and the turbulence generated by the square cells themselves. The change tendency of the mean wind velocity and the total turbulence characteristics in the decay area have been studied by varying the length to cell size ratio L/D, and ratio of distance between the square cells and the measuring position to cell size X/D.

Fluidic actuators for separation control at the engine/wing junction

2017 ◽  
Vol 89 (5) ◽  
pp. 709-718 ◽  
Author(s):  
Philipp Schloesser ◽  
Michael Meyer ◽  
Martin Schueller ◽  
Perez Weigel ◽  
Matthias Bauer
Keyword(s):  
Wind Tunnel ◽  
Flow Control ◽  
Flow Separation ◽  
Mass Flux ◽  
Large Scale ◽  
Active Flow Control ◽  
Wind Tunnel Test ◽  
Local Flow ◽  
Content Type ◽  
Active Flow

Purpose The area behind the engine/wing junction of conventional civil aircraft configurations with underwing-mounted turbofans is susceptible to local flow separation at high angles of attack, which potentially impacts maximum lift performance of the aircraft. This paper aims to present the design, testing and optimization of two distinct systems of fluidic actuation dedicated to reduce separation at the engine/wing junction. Design/methodology/approach Active flow control applied at the unprotected leading edge inboard of the engine pylon has shown considerable potential to alleviate or even eliminate local flow separation, and consequently regain maximum lift performance. Two actuator systems, pulsed jet actuators with and without net mass flux, are tested and optimized with respect to an upcoming large-scale wind tunnel test to assess the effect of active flow control on the flow behavior. The requirements and parameters of the flow control hardware are set by numerical simulations of project partners. Findings The results of ground test show that full modulation of the jets of the non-zero mass flux actuator is achieved. In addition, it could be shown that the required parameters can be satisfied at design mass flow, and that pressure levels are within bounds. Furthermore, a new generation of zero-net mass flux actuators with improved performance is presented and described. This flow control system includes the actuator devices, their integration, as well as the drive and control electronics system that is used to drive groups of actuators. Originality/value The originality is given by the application of the two flow control systems in a scheduled large-scale wind tunnel test.

Wind tunnel test and numerical simulation of wind characteristics at a bridge site in mountainous terrain

2016 ◽  
Vol 20 (8) ◽  
pp. 1223-1231 ◽  
Author(s):  
Yongle Li ◽  
Xinyu Xu ◽  
Mingjin Zhang ◽  
Youlin Xu
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Bridge Deck ◽  
Angle Of Attack ◽  
Wind Tunnel Test ◽  
Vertical Direction ◽  
Steep Slope ◽  
Mountainous Terrain ◽  
Bridge Site ◽  
Wind Characteristics

Wind tunnel test and computational fluid dynamics simulation were conducted to study the wind characteristics at a bridge site in mountainous terrain. The upstream terrains were classified into three types: open terrain, open terrain with a steep slope close to the bridge, and open terrain with a ridge close to the bridge. Results obtained from the two methods were compared, including mean speed profiles in the vertical direction and variations of wind speed and angle of attack along the bridge deck. In addition, turbulence intensities at the bridge site obtained from wind tunnel test were discussed. For mean speed profiles in the vertical direction, two methods are reasonably close for open terrain, while mountain shielding effects are evident for open terrain with a steep slope for both the methods, but the extents of effects appear different. Wind speed and angle of attack along the bridge deck are mainly influenced by the local terrain. Strong downslope wind is generated at the lee slope for the case of wind normal to top of the ridge. The comparative results are expected to provide useful references for the study of wind characteristics in mountainous terrain in the future.

Test Investigation of Velocity Distribution Considering Snow Particles Participating

2010 ◽  
Vol 439-440 ◽  
pp. 1343-1348
Author(s):  
Ke Qin Yan ◽  
Xuan Yi Zhou ◽  
Ming Gu
Keyword(s):  
Wind Tunnel ◽  
Velocity Profile ◽  
Power Law ◽  
Turbulence Intensity ◽  
Wind Tunnel Test ◽  
Test Results ◽  
Power Law Distribution ◽  
Mean Velocity ◽  
Logarithmic Distribution ◽  
Test Investigation

This paper presents the fitting expressions of mean velocity profile and turbulence intensity for wind-snow coupling conditions. Different materials were adopted to simulate the roughness of saltation snow particles to get the distribution of wind velocity in the simple wind tunnel. Test results indicate that velocity profile obeys the logarithmic distribution; the turbulence intensity obeys power law distribution. The influence height of saltation snow particles to the velocity profile limited to 10 cm above from the bed surface.

Wind Tunnel Test Investigation on Sectional Models of Chaotianmen Yangtze River Bridge

2011 ◽  
Vol 201-203 ◽  
pp. 2763-2766
Author(s):  
Cheng Qi Wang ◽  
Zheng Liang Li ◽  
Zhi Tao Yan
Keyword(s):  
Wind Tunnel ◽  
Yangtze River ◽  
Bridge Deck ◽  
Wind Tunnel Test ◽  
Wind Tunnel Tests ◽  
Force Coefficients ◽  
Test Investigation ◽  
Flutter Derivatives

By means of wind tunnel tests on the sectional models of Chaotianmen Yangtze River Bridge, some important results are obtained, including the aerostatic force coefficients with the changing of attack angles, and eight flutter derivatives for the bridge deck. The wind-resistant behavior of the bridge is evaluated.

Shape optimization and experimental research of near space airship

2018 ◽  
Vol 233 (10) ◽  
pp. 3589-3602
Author(s):  
Dongli Ma ◽  
Guanxiong Li ◽  
Muqing Yang ◽  
Shaoqi Wang ◽  
Liang Zhang
Keyword(s):  
Wind Tunnel ◽  
Shape Optimization ◽  
Drag Coefficient ◽  
Force Measurement ◽  
Wind Tunnel Test ◽  
Volume Ratio ◽  
Aerodynamic Characteristics ◽  
Near Space ◽  
Transition Position ◽  
Favorable Pressure Gradient

Shape optimization has important effects on drag reduction of the near-space airship. This paper uses the Bezier curve to parameterize the hull of the airship. Based on multiple island genetic algorithms, the optimization platform combined with different programs is established, and a kind of low drag hull is obtained by optimization. Force measurement and flow observation wind tunnel test are used to research the aerodynamic characteristics of the ellipsoid hull and the optimized hull. Results show that, optimization mainly increases the volume ratio and the favorable pressure gradient region of the hull, therefore the surface area is reduced and transition position of the hull can be delayed. Compared with the LOTTE shape, transition position of the optimized shape moved backward by 13.78%, and the volume drag coefficient is reduced by 11.1%. It is known from the wind tunnel test that compared with the ellipsoid hull, transition position of the optimized shape moves backward obviously. Under the condition that the volume Reynolds number is 2.97 × 106, compared with the ellipsoid hull, volume drag coefficient of the optimized shape can reduce by 39.0%.

scholarly journals Assessing the Capability of Computational Fluid Dynamics Models in Replicating Wind Tunnel Test Results for the Rose Fitzgerald Kennedy Bridge

CivilEng ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 1065-1090
Author(s):  
Yuxiang Zhang ◽  
Philip Cardiff ◽  
Fergal Cahill ◽  
Jennifer Keenahan
Keyword(s):  
Wind Tunnel ◽  
Bridge Deck ◽  
Wind Tunnel Test ◽  
Verification And Validation ◽  
Bridge Engineering ◽  
Test Results ◽  
Cfd Model ◽  
Cfd Simulations ◽  
Wind Tunnel Tests ◽  
The Rose

Despite its wide acceptance in various industries, CFD is considered a secondary option to wind tunnel tests in bridge engineering due to a lack of confidence. To increase confidence and to advance the quality of simulations in bridge aerodynamic studies, this study performed three-dimensional RANS simulations and DESs to assess the bridge deck aerodynamics of the Rose Fitzgerald Kennedy Bridge and demonstrated detailed procedures of the verification and validation of the applied CFD model. The CFD simulations were developed in OpenFOAM, the results of which are compared to prior wind tunnel test results, where general agreements were achieved though differences were also found and analyzed. The CFD model was also applied to study the effect of fascia beams and handrails on the bridge deck aerodynamics, which were neglected in most research to-date. These secondary structures were found to increase drag coefficients and reduce lift and moment coefficients by up to 32%, 94.3%, and 52.2%, respectively, which emphasized the necessity of including these structures in evaluations of the aerodynamic performance of bridges in service. Details of the verification and validation in this study illustrate that CFD simulations can determine close results compared to wind tunnel tests.

Static Force Measurement Technology Wind Tunnel Test

2013 ◽  
Vol 423-426 ◽  
pp. 1689-1692
Author(s):  
Dun Jin ◽  
Yue Ming Yang ◽  
Jie Wu ◽  
Li Min Song ◽  
Song Li
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Force Measurement ◽  
Spin Dynamics ◽  
Limit State ◽  
Wind Tunnel Test ◽  
Measurement Technology ◽  
Static Force ◽  
Aerodynamic Test ◽  
High Angles Of Attack

Static force measurement aerodynamic wind tunnel test data provided by the aircraft normally used to predict the stall characteristics, predicted aircraft deviated,spin Sensitivities, numerical simulation of aircraft stall, spin dynamics and so on. Based on practical flight, the paper analyzed the harm of limit state flight-spin to the flight safe, emphasized the static force test techniques at high angles of attack, and obtained a series of aerodynamic test date, managed them to spin prediction analysis.

scholarly journals Identification and Application of the Aerodynamic Admittance Functions of a Double-Deck Truss Girder

2019 ◽  
Vol 9 (9) ◽  
pp. 1818 ◽  
Author(s):  
Haosu Liu ◽  
Junqing Lei ◽  
Li Zhu
Keyword(s):  
Wind Tunnel ◽  
Turbulent Flows ◽  
Force Measurement ◽  
Wind Tunnel Test ◽  
Element Model ◽  
Fish Bone ◽  
Lateral Direction ◽  
Segment Model ◽  
Long Span ◽  
Unsteady Effect

This paper presents the aerodynamic admittance functions (AAFs) of a double-deck truss girder (DDTG) under turbulent flows. The objective of the investigation is to identify AAFs using a segment model wind tunnel test. All of the wind tunnel tests were based on the force measurement method and conducted in a passive spire-generated turbulent flow. The segment model adopts a typical DDTG section and is tested in the service and construction stages under 0°, 3°, and 5° wind attack angles. Furthermore, a nonlinear expression is put forward to fit the identified AAFs. The buffeting responses of a long-span road-rail cable-stayed bridge are then calculated for both the service and construction stages using an equivalent ‘fish-bone’ finite element model of the DDTG. The unsteady effect of the buffeting force is considered based on quasi-steady buffeting theory using the identified AAFs. The calculated buffeting responses are finally compared with those for two other AAFs (AAF = 1.0 and the Sears function). The results indicate that the traditional AAFs overestimate vibrations in the vertical and torsional directions but underestimate vibrations in the lateral direction. The identified AAFs of the DDTG can be regarded as a reference for wind-resistant designs with similar girder sections.

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