OBJECTIVES:
Provision of access to the following infrastructure(s):
UNIGE Wind Tunnel and WindCube 400S
Name of the infrastructure and its installations:
UNIGE GS-WinDyn laboratory. The installations to which the access will be granted are:
(i) Wind Tunnel and
(ii) Doppler Wind Lidar system – Leosphere WindCube 400S
Location (town, country) of the infrastructure:
(i) The Wind Tunnel is located in DICCA Laboratory, University of Genoa, Viale Cambiaso, 6 – 16145 Genoa (GE), Italy.
(ii) The WindCube 400S wind lidar is installed in the western part of the port of Genoa, Genoa (GE), Italy, on a quay at 5 m above sea level.
Web site address:
(i) https://www.gs-windyn.it/wind-tunnel/
(ii) http://www.thunderr.eu/wind-monitoring/
Reference contact for potential TA user groups:
Maria Pia Repetto – repetto@dicca.unige.it
DESCRIPTION OF THE INFRASTRUCTURE:
The Giovanni Solari Wind Engineering and Structural Dynamics (GS-WinDyn, http://www.gs-windyn.org) Research Group is part of the Department of Civil Chemical and Environmental Engineering (DICCA), Università degli Studi di Genova (UNIGE), Italy, and it has been providing training and developing research activity in the field of wind engineering for over 40 years. The GS-WinDyn realises and manages experimental facilities targeting high performance experimental research on model prototypes and full-scale real structures. The installations of UNIGE GS-WinDyn Group open for TA are:
(i) Closed circuit Atmospheric Boundary Layer Wind Tunnel (short name: Wind Tunnel);
(ii) Doppler Wind Lidar system – Leosphere WindCube 400S. (short name: WindCube 400S);
(i) The UNIGE Atmospheric Boundary Layer (ABL) Wind Tunnel, located within the Laboratory of the Dept of Civil, Chemical and Environmental Engineering (DICCA) – University of Genoa, is a closed loop subsonic circuit. The wind is generated by a 1,8 m diameter axial fan powered by a 132kW engine. The rotational speed of the fan, and consequently the wind speed in the test section, can be accurately varied using a frequency control. The flow velocity in the working section reaches about 32 m/s. The working section is 8.8 m long, with a cross-section of 1.70 (width) x 1.35 (height) m. The wind tunnel features two different test sections. The former test section (TS1) is located immediately after the contraction cone, at the beginning of the working chamber, and it is mainly used for aerodynamic and aeroelastic testing of sectional models as portions of bridge decks and structural elements. In such a test section the velocity is uniform within ± 1%, and the wall boundary layer has a thickness of the order of 2 cm. The level of turbulence is less than 0,25% at any wind speed, and it can be increased by inserting suitable devices, such as grids. The latter test section (TS2) is placed at the end of the working section. It is equipped with an automated turning table and is mainly used to evaluate the action of wind on structures (e.g., buildings, wind turbines, roofs and ships) and the pedestrian comfort, and to analyse the wind fields in topographically complex terrain. The naturally developed ABL can be increased and modelled by means of artificial roughness blocks and spires up to 70 configurations corresponding to different real atmospheric boundary layers.
The UNIGE Win Tunnel is equipped with the following state-of-the-art equipment: (1) two high-precision force balances, which can be used in sectional static tests (TS1) and in ABL tests on buildings and ships (TS2); (2) two high-precision stepper motors for the rotation of sectional models, positioned in TS1 and generally used for static tests; (3) a dynamic 2-degree-of-freedom rig located in TS1, equipped with eddy current dampers capable of simulating the desired damping ratio during aeroelastic tests; (4) four high-precision laser measurement sensors, used in TS1 for aeroelastic tests, often accompanied by integrated accelerometers (placed on the dynamic rig or directly on sectional models); (5) high precision (360 channels) and very high precision (96 channels) pressure measurement systems, which can be used in TS1 and TS2, for both static and dynamic tests; (6) two 3-component wind speed measurement systems (multi-hole cobra probe); (7) wind speed measurement systems near surfaces, generally used for pedestrian comfort analysis (Irwin and Kanomax probes).
Furthermore, UNIGE Wind Tunnel has a system for the visualization of the flow and, in sharing with other UNIGE laboratories, can make use of a Stereo Particle image velocimetry (PIV) for visualization and measurements of the flow in the wake of bluff-bodies, and a hot-wire system for flow velocity measurements. UNIGE Wind Tunnel, although specialized in the simulation of stationary wind flows, typical of synoptic events, is very interested in the simulation of non-stationary events, such as thunderstorms. In addition to traditional grids for turbulence simulation in TS1, in recent months it has developed a first prototype of special grids to generate wind profiles representative of thunderstorm events.
(ii) The WindCube 400S is a state-of-the-art heterodyne pulsed Doppler Lidar which can scan the atmosphere using fully configurable PPI (Plan Position Indicator) and/or RHI (Range Height Indicator) mixed patterns or DBS (Doppler Beam Swinging). It is the most powerful scanning Lidar produced by Vaisala-Leosphere (https://www.vaisala.com/en/wind-lidars), one of the leading companies in wind Lidar technology worldwide, with the capability to take measurements up to ranges of 15 km and 50 m physical resolution. The instrument was installed on a quay at 5 m above sea level, in a position sheltered by the port dam from sea waves and located inside a restricted area managed by the Port Authority of Genoa. It is connected to the power supply through a UPS and communication is guaranteed via an optic fibre connection. Remote access to the Lidar is restricted through IP address control. Remote control of the Lidar and data retrieval is fully configurable using the proprietary software. The WindCube 400S was purchased in the framework of the ERC-funded Project THUNDERR (grant agreement No. 741273, www.thunderr.eu) with the strategic purpose of measuring thunderstorm outflows and to collect unique and unavailable quantitative data concerning the impacts of non-synoptic flows on structures as well as port and airport infrastructures. This investment was also expected to open new perspectives in the wind engineering sector in terms of full-scale measurements of synoptic and unsteady flows to properly understand their actions on the built environment, to complement and validate the experimental tests in wind tunnel that are commonly used by wind engineers for design and standard codification. Besides, thanks to its user-configurability and power, this scanning Lidar is highly suitable for applied and theoretical research in the wind energy (e.g., wind farm control and power forecast) and applied meteorology (e.g., boundary layer sounding, thunderstorm outflows measurement, pollution dispersion) sector.
Services currently offered by the infrastructure:
Thanks to its multiple experimental installations and its interdisciplinary composition, UNIGE GS-WinDyn covers almost all sectors of wind science and engineering, i.e., atmospheric physics, meteorology and climatology, aerodynamics and aeroelasticity, structural and architectural engineering, wind energy, wind risk reduction. Many visiting researchers conducted part of their activity at UNIGE GS-WinDyn, in particular 15 international researchers visited UNIGE GS-WinDyn in the last 10 years. The two installations open to T.A. offer experimental capability in aerodynamic, aeroelastic characterization of structures and structural elements (i) and full-scale free field wind flow measurement (ii).
(i) UNIGE Wind Tunnel is responsible for developing applications in Wind Engineering, with activities in the fields of pure research (to support MSc and PhD Thesis and researchers of UNIGE and other Italian and foreign universities) and applied research (to develop research projects carried out for Italian and international companies). Recent publications on peer-reviewed international journals (e.g., Calotescu et al., 2021, Rizzo et al., 2021), based on tests performed in UNIGE Wind Tunnel, are just the latest examples of activities related to international research. During the last year, more than 10 research contracts were developed on the topics of bridge and ship aerodynamics, building pressure measurements and wind environment, mainly with an English company providing wind engineering consultancy services to civil constructions, offshore and renewables industries. UNIGE Wind Tunnel has also been involved in supporting activities related to the development of guidance documents for both practitioners and governing bodies (i.e., CNR-DT 2017 R1/2018, 2019) in order to improve existing practice in wind vulnerability assessments.
(ii) The WindCube 400S scanning Lidar was installed in 2018 and will be used 100% for the purposes of ERC THUNDERR project until the end of the project in October 2021. Within the THUNDERR Project, the Lidar has been used since April 2018 in a continuous mode to monitor the atmosphere through a sequential scanning pattern based on 4 subsequential PPIs taken at different elevations with respect to the horizon (i.e., 2.5°, 5.0°, 7.5°, 10.0°). Each PPI scanned from 100° to 250° in the horizontal as the main interest was the detection of the thunderstorms originating over the Ligurian Sea and the measurement of their geometric and kinematic characteristics for statistical purposes. As an example, the measurements taken during the thunderstorm event that occurred on August 14, 2018, when the Morandi bridge collapsed in Genoa bringing about more than 40 fatalities, were used to describe in detail the gust front generated below the thundercloud base and its time-space evolution in Burlando et al. (2020).
In the context of the present proposal, the Lidar will be available to the scientific community and to customers for research projects aiming at taking measurements within the atmospheric boundary layer according to a suitable PPI/RHI/DBS or mixed configuration. UNIGE will provide customers with scientific support to define the Lidar configuration in terms of scan patterns, range, resolution, etc. and specific training to use the Lidar and its database. In addition, customers will benefit from using the SingleDop package, which is a library developed in python described in Xu et al. (2006), to retrieve 2D horizontal wind fields from single Doppler Radar scan, tuned and adapted to work with the WindCube 400S scanning Lidar data.
DESCRIPTION OF WORK:
Access to UNIGE Wind Tunnel at DICCA and to the WindCube 400S wind Lidar for carrying out specific user-defined measurement campaigns [Months: 1-48]
Modality of access under this proposal:
Transnational Access to a number of selected user-groups will be granted for the use of UNIGE Wind Tunnel (i) and WindCube 400S Doppler Wind Lidar system (ii) at DICCA – University of Genoa (Italy). Travel and subsistence costs for the users will be covered both for the preliminary meeting and for the testing phase. UNIGE Administrative staff and GS-WinDyn staff will be available to help external users to solve all the logistic issues that might arise during any phase of the research activity.
(i) Access to UNIGE Wind Tunnel will be given to projects focused on the assessment of wind actions and effects on structures, involving static and dynamic studies on scale models of real structures or structural elements. Experiments can be performed on standalone models or on models placed in their real context, reproducing the actual surroundings highlighting modifications induced by nearby structures and orography. Scale models must be agreed with UNIGE Wind Tunnel staff in order to be compatible with the size of the infrastructure (e.g., avoiding blockage problems) and its measurement capabilities. Three projects per year can be hosted. Approximately, it can be considered that each project will use about two months of access (40 working days), including training, model design and preparation, test campaign and data post-processing. For each project, about 20 days (5 meetings and model design, 15 days of tests) of exclusive use of the installation will be assured to the users. All the experimental phases can also be followed via streaming, through the use of high-definition IP cameras that UNIGE Wind Tunnel has been equipped with since 2020. The number of days indicated here refers to tests on one or two scale models, with a usual number of measurement points and angles of incidence of the flow, for different wind speeds. If tests will include more than a couple of models or more complex testing procedures, the number of days could increase. A preliminary training period is included, to get the users familiar with wind tunnel testing technologies and procedures. Access costs of the installation are declared on the basis of actual cost, as the installation does not have a separate financial administration in the UNIGE budget and unit cost cannot easily be assessed.
(ii) Access to the WindCube 400S will be given to projects focused on the Atmospheric Boundary Layer (ABL) full-scale measurement, to study specific weather phenomena (e.g., land/sea breezes, downslope winds, thunderstorm dynamics, squall lines structure, etc.) as well as extreme wind risk reduction (e.g., with respect to port operation, aviation, offshore structures, etc.). In addition, projects will be hosted aiming at using the WindCube 400S to test its capability to measure phenomena related specifically to wind engineering (e.g., vortex shedding behind real structures, fluid-structure interaction at full scale).
Three projects per year can be hosted. Approximately, it can be considered that each project will use about 2-3 months of testing phase, including about 10 working days for the instrument setup definition (2 preliminary days for meetings and surveys at the WindCube 400S location, 3-5 days of preliminary tests for setup definition and raw data acquisition, 2-3 days for preliminary post-processing) spent at the infrastructure by the external researcher(s). Access costs of the installation are declared on the basis of actual cost, as the installation does not have a separate financial administration in the UNIGE budget and unit cost cannot easily be assessed. Moreover, the installation has been used exclusively for the ERC-THUNDERR project, excluding external users until October 2021.
Support offered under this proposal:
For the complete success of the research project, each user group participating in TA will be working closely with the UNIGE GS-WinDyn staff for the whole user project duration, in order to fully exploit the resources of the infrastructures.
(i) UNIGE Wind Tunnel is fully available to provide support in all phases of the experimental activity. In particular a preliminary training period is included, to get the users familiar with wind tunnel testing technologies and procedures; specific support for the design and manufacture of scale models, necessary for the correct development of the experimental activity, will be provided. As standard for the infrastructure, each user will receive all the acquired raw data (available in the most commonly used formats), videos and photos. Additionally, based on users’ needs, routine for results interpretation can be developed in order to facilitate the users’ work, making use of the vast experience of UNIGE Wind Tunnel staff in processing the results of static and dynamic tests for both scientific purposes and technical applications.
(ii) As far as the WindCube 400S is concerned, each user group participating in TA will be working closely, for the whole setup phase, with the UNIGE staff to fully exploit the functionalities of the wind Lidar. A preliminary training period is included, to get the users familiar with the Doppler Wind Lidar system technologies and procedures. During the setup phase, real-time data will be used to adjust the testing protocol that will be operated during all the testing phases. During the measuring campaign, raw data will be sent automatically and in (near)real-time to the user group for checking and validation. UNIGE staff will be at the user group’s disposal for run-time setup adjustments. UNIGE staff will support users for post-processing and analysis of the measurements taken during the testing phases.
Outreach to new users:
UNIGE will try to attract new potential users using the web site of the GS-WinDyn research group (www.gs-windyn.eu) as well as the website of the ERC- THUNDERR Project (www.thunderr.eu), and through the most widely used professional social networks (e.g., LinkedIn and ResearchGate). Call for proposals will also be disseminated at National and International level through posts on specialized sites (e.g., https://imechanica.org/) and through the mailing lists of the Wind Engineering Associations (e.g., the Italian Association for Wind Engineering – ANIV, www.aniv-iawe.org, and the International Association for Wind Engineering – IAWE, www.iawe.org). Besides, DICCA organizes courses for the PhD program in Civil, Chemical and Environmental Engineering (http://dottorato.dicca.UniGE.it/eng/index.html) and in Security, Risk and Vulnerability (http://dottorato.dicca.unige.it/eng/rrenib/) spreading state-of-the-art knowledge regarding many different aspects of Wind Engineering and Structural Dynamics. During these courses, Wind Tunnel activities are often mentioned and used as a base for practical examples. In the last 10 years SMEs and industries cooperated closely with UNIGE Wind Tunnel, through the development of numerous research projects, aimed at technical assessments. An EC funded TA activity will help achieve new SME users as many requests for testing in the Wind Tunnel are aborted because the innovation/research costs are often not affordable in terms of SMEs’ budget. Furthermore, an EC funded TA activity will also allow the in-depth analysis of phenomena beyond a mere technical evaluation of wind-induced effects, with possible significant repercussions at both scientific and technological levels. Concerning pure research topics in the aerodynamic and aeroelastic field, EC-funded TA activities will really boost basic and curiosity-driven research which is often not feasible due to insufficient resources.
