DOI: 10.5281/zenodo.12627184
title: Behavior of Telecommunication Lattice Towers to Thunderstorm Winds
title: ERIES-BOLT

description: Dataset Description

This work aims at closing the knowledge gap between the wind field monitoring of real structures and wind tunnel testing by simulating real atmospheric boundary layer (ABL) and thunderstorm events in the Wind Energy, Environment, Engineering (WindEEE) research facility. The real events were acquired by a wind and structural monitoring system installed on a 50 m telecommunication lattice tower located in Sânnicolau Mare, Romania. The study reproduces complex downburst wind systems, in a controlled laboratory environment, like those observed in the field monitoring. The wind-induced response of two typical telecommunication lattice towers of different heights, i.e. 50 m and 90 m is investigated by means of both aerodynamic and aeroelastic tests. The acquired data will allow to compare and calibrate wind tunnel test results with field monitoring structural data measured during intense ABL and thunderstorm winds by the Sânnicolau Mare monitoring system. This extends the wind field and aerodynamic database which can be further utilized for codification purposes and for validating numerical and analytical models. The proposed work aims to advance code-based design of telecom lattice towers to thunderstorm winds.

This work involved three areas of testing – wind field characterization to determine the best settings to match full scale / realistic wind loads, aeroelastic tests of both a 90m and 50m full towers (1:100 scale) using strain gauges as well as force balances, and a 1:10 sectional model of the top of the 50m tower to study the aerodynamics of the tower both with and without ancillaries added

 

S0. Documentation

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

 

S1. Wind Profile Stand

A vertical stand of 11 TFI cobra probes measured wind field data at heights of 50, 100, 150, 200, 300, 400, 500, 600, 700, 800, and 900 mm from the ground surface. For each experiment described below, the Cobra Probe stand was located in select locations to capture the near-surface flow.

E1. ABL Profile Development

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. Each fan on this wall is individually controlled allowing a versatile range of ABL flow conditions. In addition, the ABL flow turbulence and boundary layer gradient were fine-tuned using roughness elements and spires.

E2. Downburst Profile Development

An impinging-jet style downburst is generated at the WindEEE dome through the release of pressure from a plenum above the testing chamber. The plenum is pressurized with six large fans for an adjustable amount of time or until a certain pressure is achieved. The built pressure then releases through a bell mouth with variable orifice sizes, D, to achieve a rapid downdraft of air. Given WindEEE’s unique 3-D test chamber, measurements were taken at various angles, theta, and radius, r, from the centre of the bell mouth. Commonly, these measurement locations are indicated by a non-dimensional parameter, r/D, and the angle, ϑ (theta).

E3. Combined Downburst and ABL Profile Development

With the unique capability of the WindEEE test chamber, profile measurements were taken while operating various combinations of the ABL and downburst-like flow configurations. The natural occurrence of a downburst in a storm acted as a driver for this segment of profile development.

E4. Downburst with Radial Trip Profile Development

For this test, wooden trips about 15cm tall were evenly placed all around the edge of the turntable. The downburst-like flow was generated similar to the downburst profile development section.

 

S2. 1-100 Scaled 50m Lattice Tower Model (T50)

This specimen included a triangular lattice tower of 50m built to a scale of 1:100. The model was made from a mixture of stainless-steel tubing for the spines and bracing elements while the joints were made from 3D printed PolyJet material. The models were fastened to a steel base measuring 14 by 14cm that is 1.27cm thick. A gradual ramp that sloped at a 1:12 angle was placed around this base extending 30.48cm. The model was placed on a mobile setup to be placed in experiment specific locations, as described below.

E1. ABL Wind Load

The described specimen was tested under wind profiles developed from Specimen 1, Experiment 1.

E2. Downburst Wind Load

The described specimen was tested under wind profiles developed from Specimen 1, Experiment 2.

E3. Combined Downburst and ABL Wind Load

The described specimen was tested under wind profiles developed from Specimen 1, Experiment 3.

E4. Downburst with Radial Trip Wind Load

The described specimen was tested under wind profiles developed from Specimen 1, Experiment 4.

 

S3. 1-100 Scaled 90m Lattice Tower Model (T90)

This specimen included a triangular lattice tower of 50m built to a scale of 1:100. The model was made from a mixture of stainless-steel tubing for the spines and bracing elements while the joints were made from 3D printed PolyJet material. The models were fastened to a steel base measuring 14 by 14cm that is 1.27cm thick. A gradual ramp that sloped at a 1:12 angle was placed around this base extending 30.48cm. The model was placed on a mobile setup to be placed in experiment specific locations, as described below.

E1. ABL Wind Load

The described specimen was tested under wind profiles developed from Specimen 1, Experiment 1.

E2. Downburst Wind Load

The described specimen was tested under wind profiles developed from Specimen 1, Experiment 2.

E3. Combined Downburst and ABL Wind Load

The described specimen was tested under wind profiles developed from Specimen 1, Experiment 3.

 

S4. Aerodynamic lattice tower sectional model

This specimen included a 1 m tall section of the top of the 50 m tower at a scale of 1:10. It is constructed of brass, steel, 3D printed nylon, PolyJet 3-D printed material, and steel screws. The antennas, railing and central ladder are all removable. The model was mounted on a rig made up of a 12.7 cm diameter steel pipe and a wooden base plate. The rig stands 60cm tall so that the model is above the sheared surface flow. The base and top plates of the rig were 90cm in diameter. The experiments were performed with three different configurations of the model.

E1. Aerodynamics of the Bare structure without Top Plate

During this test, the model was measured as a bare structure (no antennas, ladders, or other components). The model was tested under ABL flow to outline the aerodynamic effects of the baseline model.

E2. Aerodynamics of the Structure with Top Plate

During this test, a top plate hovered over the model for the entirety of the test program. This plate encourages 2-D flow properties in ABL flow to mimic aerodynamic properties seen in horizontal testing in traditional wind tunnels.

E3. Aerodynamics of the Structure with Ancillary Components

During this test, ancillary components including ladders, railing, and antenna were attached to the model. These items act to increase the frontal area of the model which are expected to change the aerodynamic properties of the model.

 

Note: Given the number of data files captured in this program, the files required to be uploaded in compressed '.zip' folders.