Understanding Near-Ground Tornado Flows - Pressure, Shear and Turbulence, and their Importance in Structural Loading

Dataset Description

The research focuses on the velocity and pressure field of the near-ground region within one of the Wind Engineering, Energy, and Environment (WindEEE) Dome's tornadic-like flow simulations. This research also aims to provide valuable insight in the behaviour between tornado-building interactions. Measurement regions of interest range from the apparent centre of the tornado-like flow structure extending beyond twice the radius of maximum tangential velocity.

Two vortex cases were simulated and measured:

(1) TV0 - a stationary vortex where the bell mouth (updraft centre) aligns with the centre of the test chamber, and

(2) TV1 - a vortex translating for a distance of 4.5 m at a nominal translation speed of about 1-1.2 m/s.

S0. Documentation

Contains information documents regarding the instrumentation specifications, test plan, and other important diagrams.

S1. Near-Ground Flow Model

TV0 and TV1 simulations were tested at the WindEEE Dome testing facility. Velocity measurement devices were used to characterize simulated vortex's horizontal flow field at heights of 3.2, and 7.2. Pressure measurement devices were used to characterize the vortex's ground surface pressure. These measurements aim to provide data for more accurate tornado wind field models.

E1. Near-Ground Velocity Field

During this test, 3-D point measurements were taken to aid in characterizing TV0 and TV1 simulations. Measurements were taken at locations R = 0, 60 and 105 cm measured perpendicularly from the bell mouth's path of translation. Two heights and four point positions were captured at each location. These measurements aim to provide detailed characteristics of the wind field.

E2. Ground Surface Instantaneous Pressure Field

A ground surface pressure model covering an area of 120 cm by 300 cm was used to characterize the ground pressure distribution of simulations: TV0 and TV1. Instantaneous pressure measurement devices captured the flow distribution throughout a 2-D grid of pressure taps mounted flush with the ground surface panels.

S2. Low-Rise Building Model

A 3:12 roof slope, 1:100 scale, low-rise building model was instrumented with external surface pressure taps and tested under TV0 and TV1 flow simulations at WindEEE. The low-rise building model was measured in locations R = 0, 60, and 105 cm measured perpendicularly from the bell mouth translation pat, and at azimuth angles 0, 45, and 90 degrees relative to the path of the bell mouth.

E1. Low-Rise Building Aerodynamics

The effects of stationary and translating vortices on a low-rise building model were investigated.

S3. Small-Portable Temporary Building Model

A temporary low-rise building was instrumented with external surface pressure taps and tested under TV0 and TV1 flow simulations at WindEEE. The small-portable building model of size 1.2 cm by 1.2 cm by 3.2 cm (1:70 scale) and ground surface model covering 120 cm by 300 cm. The small-portable building was measured in locations R = 0, 60, and 105 cm measured perpendicularly from the bell mouth translation path.

E1. Small-Portable Temporary Building Aerodynamics

The effects of stationary and translating vortices on a small-portable building model were investigated.

S4. Near-Ground Particle Image Velocimetry (PIV)

A Continuum laser was focused and split through a cylindrical lens into a thin laser sheet, fog machines were used to seed the entire test chamber with long lasting fog fluid, and finally synchronized high-resolution cameras (flares) were used to capture laser light refraction. Flares send image data to the DVR Express Cores during test measurements. This PIV system was used to measure the horizontal velocity field of simulations: TV0 with an approximate total coverage of 80 cm by 240 cm.

E1. Near-Ground Horizontal Velocity Field

The PIV system was used to measure the 2-D velocity field at a height of 7.2 cm from the chamber floor. The plane of measure covers regions from the tornado-like flow's apparent centre to beyond the region of maximum tangential velocity.

E2. Low-Rise Building Wake Aerodynamics

A low-rise building model was measured at the centre of the test chamber, subject to the tornado vortex TV0. The model was made black to absorb energy and light from the PIV laser. The PIV system was used to measure the 2-D velocity field at a height of 7.2 cm from the chamber floor.

Note: Due to storage limitations we cannot include the entire PIV raw dataset, however data can be made available apon request. Please email the project contact person or the hosting instution (Contact – WindEEE Research Facility) for information or access to the complete dataset.