ProMoTWA

2025 - 2025

Wind Eng.

Francesco Ricciardelli

Girma Bitsuamlak

Alberto M. Avossa

Vincenzo Picozzi

John Dalsgaart Sorensen

Mark Sterling

+2 more

2025 - 2025

Wind Eng.

Probabilistic Modelling of Thunderstorm Wind Actions

ProMoTWA

Wind loads

Wind pressures

Aerodynamic forces

Dataset Description

The dataset comprises non-stationary pressure and velocity measurements collected on a low-rise building with a duo-pitch roof subjected to various thunderstorm wind conditions, including atmospheric boundary layer (ABL) flows, downbursts, and combined ABL–downburst interactions. Measurements were performed in the WindEEE Dome using wind-tunnel simulations designed to replicate realistic thunderstorm events.

The building geometry matches that of the ERIES-TNG project, allowing direct comparisons with existing tornadic and ABL wind loading data. The dataset includes time-resolved pressure recordings on the building surfaces and 3-D flow velocity profiles around the structure, enabling the calculation of pressure coefficients, analysis of cladding and MWFRS design wind loads, and investigation of the underlying flow physics responsible for the observed pressures.

This dataset supports probabilistic assessments of thunderstorm wind effects, facilitates comparisons with traditional ABL and tornado-induced loads, and provides a foundation for developing downburst hazard models for low-rise structures.

Aerodynamics

low-rise building model

Downburst Wind

ABL Wind

Ground Pressure

Building Pressure

Specimens

1. Wind Profile Development (S1)

Simultaneous surface wind velocity and ground pressure measurements were taken to characterize wind profile of simulated thunderstorm winds including atmospheric boundary layer (ABL) flows, downburst-like flows, and combined ABL–downburst flows. Three-component wind velocities were measured using Turbulent Flow Instruments (TFI) Cobra Probes which were mounted on to a vertical rack at heights of 2.5, 5.0, 10.3, 15.0, 20, 30.0, 40.0, and 50 cm above the ground surface.

To capture ground surface pressures, instrumented ground panels were employed. A primary panel measuring 121.9 cm × 121.9 cm was equipped with 112 pressure taps, and a circular disk of 61.0 cm diameter was installed on the panel to surround the profiling rack. The disk contained an additional 30 taps and was offset from the panel center by 16.5 cm. During variations in radial distance (r/D) and azimuthal position (φ), the ground panels were translated with the profiling rack.

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1. Atmospheric Boundary Layer (ABL) Flow Profiling (E1)

An atmospheric boundary layer (ABL) flow representative of open-country terrain was generated using the 60-fan wall located on one side of the hexagonal WindEEE test chamber. To establish the ABL profile, 13 triangular spires were installed upstream of the measurement location. Each spire measured 120 cm in height and 40 cm at the base, and the array was positioned 100 cm downwind from the 60-fan wall. The spires were designed to induce a vertical wind-speed gradient and turbulence intensity profile consistent with an open-country ABL, promoting flow development prior to the model testing position. ABL wind of various strength were generated by operating the fans at the 40%, 60%, and 90% of their rated fan speed.

Instrumentation

The instantaneous wind velocities of the ABL flows were captured using eight synchronized TFI cobra probes. The probes measured the u-, v-, and w-velocity components, along with a reference pressure in separate channels on the TFI data acquisition system. Data were sampled at a frequency of 625 Hz for a duration of 120 s for each run. Whereas ground surface pressure measurements were taken using PSI pressure scanners with a measurement range of ±4 in. H₂O (±996 Pa). Each pressure taps on ground surface panels were connected to the scanners through flexible tubing

2. Downburst-like Wind Profiling (E2)

In the WindEEE Dome, an impinging-jet style downburst was created by releasing pressure from a plenum above the test chamber. The resulting flow began as a high-velocity jet striking the ground, which then spread outward in a radial outflow. To control the flow, the upper fans were operated at 30% of their capacity, and the downburst bell mouth, with a diameter of 3.2 m, set the characteristic scale of the impinging jet.

To capture the structure of this complex flow, 3-D point measurements were taken using a profiling rack, employing the same methodology as for the ABL experiments. The rack was positioned at radial distances r/D = 0.4, 0.6, 0.8, 1.0, 1.2, and 1.4 along an azimuthal line of φ = 180°. At the farthest radial location (r/D = 1.4), the ground plates remained at r/D = 1.2, with only the rack shifted to maintain alignment with the turntable constraints while still capturing the full flow development.

Instrumentation

Ditto to S1.E1, but velocity and pressure data were sampled for a duration of 30 s for each run. And each test case was repeated eight times to allow ensemble averaging of the flow statistics.

3. Combined DB- ABL Wind Profile (E3)

To investigate the interaction of atmospheric boundary layer (ABL) flows with downburst-like events, the WindEEE Dome was configured to simultaneously generate ABL and impinging-jet downburst flows.

For the ABL component, a 60-fan wall was operated at 40% and 60% of its capacity to generate mean wind speed profiles representative of open-country terrain. Thirteen triangular spires, each 120 cm high and 40 cm at the base, were positioned 100 cm downstream of the fan wall to induce a vertical wind-speed gradient and realistic turbulence intensity profile.

For the downburst component, the upper fans were set to 30% of their operational limit to produce a high-velocity impinging jet through downdraft opening diameter D = 3.2 m. This configuration created a combined flow field in which the ABL profile was modulated by the radial outflow of the downburst, capturing realistic interactions between both phenomena.

Instrumentation

The instrumentation setup is the same as in S1.E2 except the profiling rack was positioned at a radial distance of r/D = 1 and at azimuthal positions φ = 180°, 202°, 225°, and 247°, oriented toward the center of the bell mouth to ensure accurate characterization of the flow at multiple angles.

2. Low-Rise Building Model (S2)

A rigid low-rise building model with a duo-pitch roof of 3:12 slope was constructed. The model measured 38.1 cm in length, 24.5 cm in width, and 7.2 cm in height to the eave line. The model was fabricated from acrylic and instrumented with 501 external surface pressure taps distributed across the walls and roof surfaces, in addition to 10 internal taps for measurement of interior pressures.

The ground surface pressure around the model building was measured using the pressure setup described in section S1. The model mounting disk contained an additional 30 taps and was offset from the panel center by 16.5 cm to accommodate model placement. During variations in radial distance (r/D) and azimuthal position (φ), the ground panels were translated with the model. For changes in building orientation angle (θ), only the taps on the circular disk were rotated with the model, while the remaining ground panels remained fixed.

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1. ABL Wind Loading (E1)

The building model described in Section S2 were tested under ABL wind profiles generated as described in Section S1.E1. The center of the building model was positioned at a radial distance of r/D = 1 and an azimuthal position of φ = 180°. Building orientation angle (θ) varied depending on the imposed flow condition. For tests conducted at 90% fan speed, θ was incremented from 0° to 90° in 10° intervals. For tests conducted at 40% and 60% fan speeds, θ was restricted to 0° and 90°. The percentiles 40%, 60%, and 90% correspond to operational fan speed relative to the rated upper limits of the WindEEE Dome fans mounted on the 60-fan wall of the test chamber. The ABL flow simulation tunnel setup is as described in Section S1.E1.

Instrumentation

Pressure measurements were obtained using PSI pressure scanners with a measurement range of ±4 in. H₂O (±996 Pa). All 653 pressure taps on the building model and ground surface panels were connected to the scanners through flexible tubing. Pressure data were sampled at a frequency of 500 Hz for a duration of 120 s for each run. A reference static and dynamic pressure were measured using a pitot tube.

2. DB Wind Loading (E2)

The building model described in Section S2 was tested under DB winds simulated as detailed in S1.E2. The center of the building model was positioned at radial distances of r/D = 0.8, 1.0, and 1.2 and an azimuthal position of φ = 180°. Building orientation angle (θ) was varied from 0° to 90° in 10° increments for all tests. The upper fans of the WindEEE Dome were set to 30% of their operational limit to generate the downburst-like flow.

Instrumentation

Pressure measurements were obtained using instrumentation setup described in Section S2.E1. However, data was sampled for duration of 30 second and each test run case was repeated 8 times.

3. Combined DB- ABL Loading (E3)

The building model described in Section S2 was tested under wind profiles generated as detailed in Sectin S1.E3. The building model was positioned at a radial distance of r/D = 1 and at azimuthal positions of φ = 180°, 202°, 225°, and 247°. Building orientation angle (θ) varied from 0° to 90° in 10° increments and was measured relative to the center of the bellmouth.

The background ABL flow was generated by operating, the 60-fan wall at 40% and 60% of its operational limit, And the impinging jets were produced by running the fans in the upper plenum at 30% of their operational limit.