DOI: 10.5281/zenodo.18553669
title: Aerodynamic performance of bridge decks subjected to downburst-like non-stationary outflows
title: ERIES-AEROBURST

description: Dataset Description 




This research investigates non-synoptic, non-stationary downburst-like wind effects on long-span bridge sections. The study is motivated by field observations of unusually strong responses of long span bridges in Norway (Petersen et al., 2020) and the United Kingdom (Owen et al., 2020) under winds exhibiting transient behaviour. To get an insight on the differences between the effects of synoptic and downburst-like winds on flexible bridges, static and dynamic section model tests were conducted under combined straight and impinging jet outflow winds simulated at the WindEEE Dome. under.  This dataset consists of measurements of wind profiles used for testing the models, surface pressure measurements of the static section model, and vibration and force measurements of the dynamic section model.  

 



S0. Documentation 




This folder contains important documents that pertain to the project.  



 

S1. Vertical Profile Development (Rack 1) 




ABL, downburst-like, and the combination of downburst-like and ABL wind simulations were measured in a near-empty chamber. Turbulent Flow Instruments (TFI) Cobra Probes were used to characterize wind profiles and were mounted on to a vertical rack at heights of 5, 7.5, 10.0, 15.0, 20, 30.0, 40.0, and 50 cm above the ground surface. The location of the vertical profile varied between the experiments outlined below. 




 




E1. Downburst-like Wind Profiling  




Description: 




An impinging-jet style downburst is generated at the WindEEE dome through the release of pressure from a plenum above the testing chamber. Like the ABL measurements, 3-D point measurements were taken to characterize the velocity profiles for downbursts. For the downburst simulations, two parameters were varied: the strength of the impinging jet flow and the position of the bell mouth (r_jet) in the WindEEE dome. 




The vertical rack was positioned at a radial distance from the center of the turntable, rm = 320 cm, and with model angular position, φ = 180 degrees. The bell mouth position r_jet = -192, -128, -64, 0, 64, and 128 cm from the centre of the turntable. These positions achieved r/D ratios of 1.6, 1.4, 1.2, 1, 0.8, and 0.6. These measurements aim to provide detailed characteristics of the wind profile as it develops radially. 


 



 




E2. Atmospheric Boundary Layer (ABL) Flow Profiling  




Description: 




The 60-fan wall located on one side of the hexagonal shaped WindEEE test chamber was used to generate the various ABL flows for this experiment. During the experiment, 3-D point measurements were taken to characterize the velocity profiles for numerous uniform smooth flow wind speeds. 




The vertical rack (where the measurements of the profile are taken) was positioned at radial distance (rm) of 320 cm and at an azimuth angle φ = 180 degrees. The reference measurements were taken at a height of 50 cm. 


 



 




E3. Combination Downburst-like and ABL Wind Profiling  




Description: 




In combination with the described downburst simulation in ‘S1. E2.’, these impinging-jets can be run simultaneously with the 60-fan wall (described in ‘S1. E1’) to achieve ABL and downburst-like flow combinations. During this experiment, 3-D point measurements were taken to characterize the velocity profile for a downburst with ABL wind. 




The vertical rack was positioned at a radial distance from the center of the turntable (rm) at 320 cm and with φ=180, and 210 degrees. The bell mouth position r_jet = 0 cm from the centre of the turntable. 


 



 




S2. Horizontal Profile Development (Rack 2) 




ABL, downburst-like, and the combination of downburst-like and ABL wind simulations were measured in a near-empty chamber. Turbulent Flow Instruments (TFI) Cobra Probes were used to characterize wind profiles and were mounted on to a horizontal rack at heights of 10, and 20 cm above the ground surface. The probes were spaced relative to the centre of the rack perpendicular to the ABL wind direction at distances of -60, -45, -30, -15, -7.5, 0, 15, 30, 45, and 60 cm. The location of the horizontal profile varied between the experiments outlined below. 




 




E1. Downburst-like Wind Profiling  




Description: 




An impinging-jet style downburst is generated at the WindEEE dome through the release of pressure from a plenum above the testing chamber. Like the ABL measurements, 3-D point measurements were taken to characterize the velocity profiles for downbursts. For the downburst simulations, two parameters were varied: the strength of the impinging jet flow and the position of the bell mouth (r_jet) in the WindEEE dome. 




The vertical rack was positioned at a radial distance from the center of the turntable (rm) at 320 cm and with φ=180 degrees. The bell mouth position r_jet = -192, -128, -64, 0, 64, and 128 cm from the centre of the turntable. These positions achieved r/D ratios of 1.6, 1.4, 1.2, 1, 0.8, and 0.6. These measurements aim to provide detailed characteristics of the wind profile as it develops radially. 


 



 




E2. Atmospheric Boundary Layer (ABL) Flow Profiling  




Description: 




The 60-fan wall located on one side of the hexagonal shaped WindEEE test chamber was used to generate the various ABL flows for this experiment. During the experiment, 3-D point measurements were taken to characterize the velocity profiles for numerous uniform smooth flow wind speeds. 




The vertical rack (where the measurements of the profile are taken) was positioned at radial distance (rm) of 320 cm and at an azimuth angle φ = 180 degrees.  


 



 




E3. Combination Downburst-like and ABL Wind Profiling  




Description: 




In combination with the described downburst simulation in ‘S2. E2.’, these impinging-jets can be run simultaneously with the 60-fan wall (described in ‘S2. E1’) to achieve ABL and downburst-like flow combinations. During this experiment, 3-D point measurements were taken to characterize the velocity profile for a downburst with ABL wind. 




The vertical rack was positioned at a radial distance from the center of the turntable (rm) at 320 cm and with φ=180, and 210 degrees. The bell mouth position r_jet = 0 cm from the centre of the turntable. 


 



 




S3. 1-100 Scale Static Section Pressure Model 




This specimen was a rigid 1-100 scale section of a bridge inspired by the Hardanger Bridge (HB) in Norway. HB is chosen as the UG has extensive experience on classical wind tunnel testing of the section and possesses full-scale measurements of non-stationary events that are relevant for the proposed project. The bridge cross-section is simplified as hexagonal prism with chord width of 18.3 cm, and thickness of 3.25 cm. The section model is 1.5 m (7.5 times its chord width) long in the spanwise direction, The bridge geometry is further described in the documentation and diagrams contained in this dataset. The bridge construction was made as a cavity, a cap, and supporting rods to house the pressure tubing and support the weight of the model along the span. The angle of attack (a) of the bridge was made adjustable using bearings mounted at each support ends. The model has 348 pressure taps distributed over its external surfaces as shown in the tap layout drawing. Pressure tap coordinates are available to correlate instantaneous measurements with locations covering the model. The specimen was tested under synoptic and non-synoptic wind simulations at WindEEE (e.g., ABL, Downburst-like, and ABL-Downburst Combination flows).  




 




E1. Straight Wind Loading Aerodynamics 




Description: 




This test involved the bridge section model subjected to ABL flow at a wind speed of approximately 10 m/s. The model was positioned 320 cm downwind from the center of the turntable facing the 60-fan wall (rm = 3.2 m, φ = 180°). The model angle of attack was tested at angles δ = ±5°, ±3°, and 0°, and at heights of 10 cm and 20 cm above the ground surface. 


 



 




E2. Downburst Wind Loading  




Description: 




This experiment involves testing the static section model under various simulateddownburst flow profiles  and strengths. The model was positioned 320 cm downwind from the center of the turntable facing the 60-fan wall (rm = 3.2 m, φ = 180°). The model was tested at geometric angles of attack a = ±5°, ±3°, and 0°, and at heights of 10 cm and 20 cm above the ground surface at r/D = 1.0. In addition, the radial position of the impinging jet (rjet) was varied relative to the model to achieve r/D = 0.6, 0.8, 1.2, 1.4, and 1.6, only the downburst strength was varied for these positions, the angle of attack a = 0°.  


 



 




E3. Combined Downburst and ABL Loading  




Description: 




This test involved the static section model subjected to various downburst simulations involving combinations of impinging jet outflows and an ABL head wind of approximately 4-5m/s, generated from the 60-fan wall.  The model was positioned 320 cm radially from the center of the turntable at angles of φ = 180°, and 210°. During the φ = 180° position the model was tested with angles of attack of a = ±5°, ±3°, and 0°, and at heights of 10 cm and 20 cm above the ground surface. During the φ = 210° position the model was tested with angles of attack of a = 0° for heights of 10 and 20 cm. All tests in these configurations were captured with the impinging jet at a position of r/D = 1.0 relative to the model. 


 



 




S4. 1-100 Scaled Dynamic Section Model 




This specimen was a dynamic 1-100 scale section of a bridge inspired again by the Hardanger Bridge (HB) in Norway. The bridge geometry is like that of Specimen 3; however, the construction was different. The dynamic bridge model was required to have a mass per unit length of 1.28 kg/m, a mass moment of inertia of 0.00426 kg/m, a horizontal frequency of 2.5 Hz, a vertical frequency of 7 Hz, and a torsional frequency of 18 Hz. The mass and moments of inertia were achieved by constructing this model out of a composition of high-density polypropylene foam, a carbon fiber rod, and various stainless-steel rods. The model was suspended in custom made test rig utilizing tension springs of various stiffness and taut strings which attached to the 3D-printed end plates and steel rods embedded in the foam cladding, respectively. The end plates and spring stiffnesses were specifically selected to provide the model with its design frequencies. The model was suspended 20 cm above the floor and had an angle of attack of a= 0°. The specimen was tested under simulated synoptic and non-synoptic winds at WindEEE (e.g., ABL, Downburst-like, and combined ABL-Downburst flows). 

 




E1. Straight Wind Effects 




Description: 




This test involved the dynamic section model subjected to ABL flow at various wind speeds. The model was positioned 320 cm downwind from the center of the turntable facing the 60-fan wall (rm = 3.2 m, φ = 180°). During testing, the model was set up at geometric angle of attack  a= 0°, and at heights of 20 cm above the ground surface. 


 



 




E2. Downburst Wind Effects




Description: 




This test involved the bridge section model subjected to Downburst flow of various strengths. The model was positioned 320 cm downwind from the center of the turntable facing the 60-fan wall (rm = 3.2 m, φ = 180°). The model angle of attack was tested at angles a = 0°, and at heights of 20 cm above the ground surface at r/D = 1.0. In addition, the radial position of the impinging jet (rjet) was varied relative to the model to achieve r/D = 0.6, 0.8, 1.2, 1.4, and 1.6, only the downburst strength was varied for these positions, the angle of attack  a = 0°.  


 



 




E3. Combined Downburst and ABL Effects




Description: 




This test involved the bridge section model subjected to various downburst simulations with an ABL head wind of approximately 4-5m/s, generated from the 60-fan wall.  The model was positioned 320 cm radially from the center of the turntable at angles of φ = 180°, and 210°. During the φ = 180° and 210° positions the model was tested with angles of attack of δ = 0°, and at a height of 20 cm. The impinging jet was at a position of r/D = 1.0 relative to the model for all tests.