Full-scale Test Facility Research Articles

Research on the dynamics of flame propagation and overpressure evolution in full-scale residential gas deflagration

To determine the effect of ignition height on indoor flame spread behavior and overpressure development, a comprehensive full-scale deflagration testing facility was established. Extensive experimental research was conducted within this facility. The findings indicate that indoor flame reignition and the occurrence of secondary explosions are most pronounced with intermediate ignition. Furthermore, the explosion overpressure generated during the reverse turn of shock wave propagation is greater than that produced by the forward turn. In comparison to the peak overpressure Pext in the master bedroom for top, middle, and bottom ignition, the peak overpressure Pext in the second bedroom increased by approximately 14.48 %, 15.04 %, and 19.20 %, respectively. When comparing middle ignition to top ignition, the propagation speed of shock waves in the kitchen balcony, restroom, second bedroom, and master bedroom was enhanced by 34.21 %, 40.85 %, 40.70 %, and 34.65 %, respectively. Furthermore, when comparing middle ignition to bottom ignition, the propagation speed of shock waves in these areas experienced a significant increase of 126.32 %, 124.39 %, 123.26 %, and 113.86 %, respectively. These research findings provide a theoretical foundation and empirical data to support the investigation and analysis of the causes of indoor gas explosion incidents.

Japan Atomic Energy Agency: Contribution to the Decommissioning of the Fukushima Daiichi Nuclear Power Station and the Reconstruction of Fukushima Prefecture at the Naraha Center for Remote Control Technology Development

Naraha Center for Remote Control Technology Development was established for the development and demonstration of remote control equipment and apparatus to promote the decommissioning of the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Company Holdings, Inc. The center has been in operation since 2016. The mission of the center is to contribute to the decommissioning of the Fukushima Daiichi Nuclear Power Station and the reconstruction of Fukushima Prefecture. This report describes the center’s full-scale mock-up test facility, component test equipment for the development of remote control equipment and apparatus, and virtual reality systems and their utilization for the realization of the mission.

E-Defense Shake Table Experiments Implemented by NIED and Collaborative Research Projects in 2005–2022

The three-dimensional full-scale earthquake testing facility, “E-Defense” was constructed using the 1995 Great Hanshin-Awaji Earthquake as a lesson. Until October 2022, this facility has conducted 123 experiments as part of the research and development on earthquake engineering for various purposes (e.g., the clarification of destruction processes, evaluations of seismic structural performances, functional maintenance, collapse margins, and damage control technologies). Even after its commencement, large earthquakes that significantly affected human life and socioeconomic activities occurred such as the 2011 off the Pacific coast of Tohoku Earthquake caused the Great East Japan Earthquake Disaster. These earthquakes revealed some new challenges for disaster prevention and mitigation. Such issues have also been incorporated as subjects to be addressed by the facility. This article introduces the researches and developments using E-Defense, chronologically linking them with the major earthquakes occurred in Japan after 1995. By summarizing the activities, its near-future direction is also briefly indicated.

Experimental study of the hydrodynamic and thermal performances of ventilated wall structures

The presence of a ventilated air gap behind the external cladding in a building envelope is known to have a tangible contribution to the overall performance of the wall assembly. In the present study, the hydrodynamic and thermal performances of ventilated wall structures in a full-scale test facility are experimentally investigated using data collected during a full-year measuring campaign. In particular, the impact of varying outdoor conditions, façade orientation, and thermal inertia of the walls on the airspeed in the cavity, temperature distribution on the surfaces, heat flux through the interior space, and heat flow in the air gap are evaluated. Additionally, the discussion on transient responses of the wall structure, driving forces applied to the airflow, the overall heat gain/loss through the interior surface of the wall, and heat recovery potential from the cavity are provided. Moreover, variation of the thermal resistance caused by the ventilated air-space is analyzed. The results reveal the importance of monitoring the outdoor microclimate conditions adjacent to the wall of interest to examine the performance of the wall structure properly. It is observed that the airflow characteristics in the cavity are better correlated with outdoor temperature than other weather parameters. It is shown that the thermal resistance of the ventilated cavity dynamically varies and is generally higher in the summertime compared to the wintertime. The results highlight the potential of harvested heat flow from the ventilated cavity reaching 158 kWh/month, which could be used as an additional energy source for buildings. The optimized air change rate in the air-space obtained in this research to simultaneously provide high cavity thermal resistance and high heat recovery from the air gap shows the necessity for considering a fan system to supply specific airflow in the cavity.

OECD/NEA/CSNI/WGAMA PERSEO benchmark: Main outcomes and conclusions

In the framework of the OECD/NEA/CSNI/WGAMA, an activity on the “Status report on thermal–hydraulic passive systems design and safety assessment” has been conducted. Within this activity, a benchmark exercise, based on the experimental data developed in the full scale PERSEO (in-Pool Energy Removal System for Emergency Operation) component separate effect test facility, built at SIET (Piacenza, Italy), has been proposed and carried out. An “OPEN” benchmark exercise, hosted by ENEA, has been conducted. Twelve results from eleven Organizations were submitted. PERSEO is a full-scale separate effect test facility designed to study a new passive decay heat removal system operating in natural circulation. Test 7 is a full pressure test (7 MPa) and investigates the system stability and the system operation. The accuracy of the calculated results has been evaluated both qualitatively and quantitatively. The latter has been conducted adopting the Fast Fourier Transform Based Method. The present paper summarizes the main features of the PERSEO facility and Test 7 and discusses the main results and outcome of the benchmark exercise.

Outdoor test facilities for the experimental performance evaluation of construction materials and systems: The BeTOP case

Proposing new materials and systems to improve the performance and energy efficiency of buildings is often followed by performance evaluation to monitor how they perform and contribute. Experimental performance characterization of new and existing building materials and systems is crucial to understanding their behaviour in relation to indoor environmental and conditional changes, in addition to outdoor environmental changes. Full-scale experimental test cell facilities have been at the forefront of experimental performance evaluation in building-related research, as they can provide a realistic representation of buildings, which includes environmental conditions, building structure, and operational characteristics. In this paper, the new test cell facility of BeTOP, located in the city of Toronto, Ontario, is introduced as a full-scale experimental facility with the capability of multiple practical tests simultaneously. This paper describes the characteristics of this test cell, including structure details, testing capabilities, system details, previous testing campaigns, and future testing potential. The design of such a full-scale testing facility is shown to be crucial in a continental climate, such as Toronto, to observe the long-term performance of new systems under variable boundary conditions with cold winters and hot and humid summer seasons.

The BeTOP facility for performance testing of building systems

Proposing new materials and systems to improve buildings' performance and energy efficiency often requires testing their performance in the field. Experimental performance characterization of new and existing building systems is crucial to understanding their behaviour. Full-scale experimental test cell facilities have been at the forefront of experimental performance evaluation in building-related research, as they provide a realistic representation of buildings, including environmental conditions, assembling challenges, and operational characteristics. In this paper, trends in the design and construction of outdoor testing facilities are first discussed. Then, based on the current literature and the knowledge gained through visits to multiple facilities, the new test cell facility “BeTOP”, located in Toronto (Ontario), is described. BeTOP is a full-scale experimental facility with the capacity to perform multiple experimental tests simultaneously. This paper describes its characteristics, including structure details, testing capabilities, system details, current monitoring campaigns, and future testing potential. The paper concludes by showing that the design of a full-scale testing facility is crucial to observe the long-term performance of new systems under variable boundary conditions in a continental climate with cold winters and hot and humid summers.

Empirical validation of co-simulation models for adaptive building envelopes

The thermal performance of adaptive building envelopes can be evaluated using building performance simulation tools. Simulation capabilities and accuracy in predicting the dynamic behaviour of adaptive building envelopes can be enhanced through co-simulation. However, it is unclear how accurately co-simulation can predict the performance of adaptive building envelopes and how the accuracy of adaptive building envelope models created in co-simulation setups can be assessed and validated. Therefore, this study presents new evidence on the empirical validation of co-simulation setups for adaptive building envelopes by establishing an assessment framework to determine the extent to which they can accurately represent the real world. The framework was applied to a case study to validate a co-simulation setup for a blind automation system using monitored data from MATELab, a full-scale outdoor test facility with realistic indoor and outdoor conditions. The validation of the co-simulation model of MATELab resulted in a median CV-RMSE index, a measure of model accuracy, of 5.9%. This indicates that the simulated data points have a small variance relative to the measured data points, showing a good model fit. In the future, modellers from the façade community can use the assessment framework for their co-simulation setups.

Contributions of E-Defense Shaking Table to Earthquake Engineering and its Future

A shaking table is an experimental facility consisting of a table that loads a structural specimen and actuators that produce acceleration of the table to simulate seismic motions. This is a powerful tool in earthquake engineering because it permits direct observation of the seismic responses of structures under controlled conditions. The 3-D Full-Scale Earthquake Testing Facility, known by its nickname as “E-Defense,” is the largest facility of its kind in terms of table size and operated by National Research Institute for Earth Science and Disaster Resilience (NIED). Since its start of operations in 2005, E-Defense has been contributing to earthquake engineering through as many as 113 experimental projects successfully completed as of fiscal year 2020. To elucidate its future operations as well as to provide other similar facilities with useful knowledge, this paper reviews the E-Defense experiences of operations and research conducted, shares the lessons learned from the experiences, and proposes the future challenges for continued contributions to earthquake engineering, by covering: the history of E-Defense facility operations and its challenges; the contributions of E-Defense to numerical simulation, another important area in earthquake engineering complementing experiment; publications of experimental data and metadata from E-Defense experiments; and international collaborations in experimental research projects.

Development of a full-scale apparatus to assess thermal protective performance of garments under highly intensive heat flux exposures

This study discusses the development process of a full-scale test facility composed of a high-performance radiant heating system, a life-sized instrumented thermal manikin system with sensing assemblies, associated equipment and in-house software controlling the entire system. This test system was aimed to be used to examine the behaviour of emergency-responder garments and subsequently to find weaknesses of turnout gears at critical thermal conditions greater than a standard 84-kW/m2-intensity, thereby contributing to improving the survival chance of firefighters who could be requested to execute an emergency evacuation from an unexpected growth of modern fires. To impose a target 126-kW/m2-irradiance throughout the garment-dressed manikin’s exposed surface for a limited period of time (12 s) as uniformly, consistently, stably and safely as possible, several technical aspects were considered: the amounts of heat-source power and electric power-supply; areas of heating and receiving and their geometrical relationship; a practical percentage of the maximum heater-capability; efficiencies of electric power-supply and water-cooling; movable equipment; and safety equipment. Two analytical models were encoded using a finite difference method in the LabVIEW platform to determine a burn injury distribution throughout the manikin-shell in association with the measurement data from the test system. The heating system and software were validated in respect of the heating consistency, vertical intensity variation, intensity-rise rate and discrepancies between the existing and present models. It was proved that the heating system is capable of increasing its heat emission up to 126 kW/m2 within 1.5 s, maintaining the intensity-level with less than 9-kW/m2-change for 12 s, and distributing the intensity-level with less than 11-kW/m2-variation along the vertical direction, from 45-cm- to 155-cm-height. The development process can contribute to the ability to develop a large-scale test facility to test specimens under a critical thermal exposure condition for research purposes.

HIEQLab, a facility to support multi-domain human-centered research on building performance and environmental quality

Researches on building performances and environmental quality can be performed through different approaches, including dynamic numerical simulations, in-field studies, full scale test facilities and living labs. Researches performed through full scale test facilities allow carrying out studies under controlled realistic conditions, directly involving the final users. Such approach can significantly improve the scientific research on energy efficient and healthy buildings by fostering a synergistic and user-centered innovation process. Within this context, at Politecnico di Torino, the TEBE group (Technology, Energy, Building and Environment) has designed and is realizing a full-scale facility, aimed at implementing researches on building Indoor Environmental Quality (IEQ) and energy performance. The facility will enable multi-domain studies, including thermal, air quality, acoustic and lighting aspects, involving the final user in the research process. The paper describes the features of the facility and the challenges it was conceived to face.

Numerical Analysis for Simulating the Road Environment Condition in the Full-scale Particulate Matter Testing Facility

Numerical Analysis for Simulating the Road Environment Condition in the Full-scale Particulate Matter Testing Facility

Qualification of RELAP5-3D code condensation model against full-scale PERSEO Test 9

Passive systems are being implemented in several nuclear plants already constructed, under construction or under design. The purpose of these systems is to increase the inherent safety of the plant in any transient condition, so they can provide a higher safety level in case of an accident. Best estimate thermal-hydraulic system codes, widely adopted in the nuclear field to perform deterministic safety analyses, need to be validated against the phenomena typical of passive systems (e.g. natural circulation, thermal-hydraulic behavior of large pools, low pressure phenomena, etc.). An experimental test facility called PERSEO (in-Pool Energy Removal System for Emergency Operation) was built at SIET laboratory in Piacenza (Italy) modifying the existing PANTHERS IC-PCC facility. It is a full-scale test facility aimed at studying a new passive heat removal system and it can be used to analyze the capability of system codes to simulate the related phenomena. In the present analysis, Test 9, which was performed in the PERSEO facility at around 4.1 MPa to study the activation and the heat removal capability of the proposed system, has been simulated with the RELAP5-3D code to assess its capability to predict the dominant phenomena of the transient. Particular attention has been dedicated to the analysis of condensation heat transfer coefficient computed by the code, since in previous analyses it has been found an evident underestimation of the power exchanged by the passive system. Alternative correlations for the condensation heat transfer coefficient have been identified and a correction factor for the heat transfer coefficient calculated by RELAP5-3D has been computed. After the application of the correction factor, the set composed by Nusselt-Kutateladze-Chen correlations provided the better agreement with the experimental data. Finally, the accuracy of the code calculation has been evaluated qualitatively and quantitatively by adopting the Fast Fourier Transform Based Method.

Full scale test facility for operability verification of tokamak pressure suppression system at sub-atmospheric conditions

The reliable and safe operation of tokamak fusion reactors is mainly based on radioactive contaminants confinement, achieved preserving the integrity of robust barriers, among which the Vacuum Vessel (VV) performs an essential role. The VV protection against postulated over pressurization events is guaranteed by the safety functions implemented in the Pressure Suppression System (PSS), in which steam from VV is discharged and Direct Contact Condensation (DCC) occurs at sub-atmospheric conditions. Aiming to verify the VVPSS performance of ITER machine (i.e. steam condensation efficiency at different DCC regimes with/without non-condensable), in steady state and transient conditions relevant for fusion reactor postulated events, and contribute to fill the knowledge gap regarding sub-atmospheric condensation, an extensive experimental research activity is ongoing with the Large and Full Scale Test Facility (LSTF and FSTF): designed, assembled, instrumented and commissioned at Laboratory B. Guerrini at DICI University of Pisa. This facility is mainly composed of a Steam Generator (up to 500 g/s, about 1.8 MW), three different steam lines for wide mass flowrate regulation, two air lines for mixed condensation characterization, Experimental Test Tank (92 m3, where steam condensation is investigated adopting two different spargers, scaled and full scale with 100 and 1000 holes, respectively), Auxiliary Tank (10 m3 for plant conditioning), Vacuum Pump, Chiller and Water Storage Tank (15 m3). Two Steam Storage Tanks (15 m3 each) allow to accumulate and provide the foreseen steam peak flowrate value (of 5 kg/s) in the postulated accident. FSTF is highly instrumented (81 thermo-resistances, 28 thermocouples, 35 pressure transmitters, 18 strain gauges and 4 vortex flow meters) and fully remotely controlled (64 on-off and control valves) by a dedicated Data Acquisition and Control System (DACS). Six video cameras and 4 led lights assure steam injection video-recording, for detailed characterization of condensation regimes. Preliminary results are shown for 50 g/s of steam injected through the scaled sparger into water pool at 30 °C with cover gas at 0.1 bar absolute, providing a condensation efficiency of about 100% and verifying instable chugging condensation regime.

The ACONIT project: an innovative design approach of active flow control for surge prevention in gas turbines

The objective of the ACONIT project is to design, manufacture and test actuators for flow control for an implantation in an aircraft engine. The actuators will fulfil aeronautics requirement in order to increase the Technology Readiness Level (TRL) in this domain. In particular, for the present proposal, one plans to focus on the extension of the stable operating range of axial compressor, allowing thus a reduction of the surge margin through postponing the stall onset. To do so, the first objective of the work is to improve the knowledge of the flow physics of an efficient flow control system by joint numerical and experimental analyses performed in a low speed, single stage axial compressor. The results of this analysis will be used to derive the fluidic specifications for high-TRL actuators and control systems. These specifications will be the base for the design and manufacturing of amplified piezo-electric actuator prototypes whose fluidic performance and operational performance in an environment with vibration and controlled level of temperature will be precisely evaluated before manufacturing final actuators that will be integrated in a full-scale engine test facility. Their performance will be evaluated in terms of Surge Margin Improvement (SMI) as well as in terms of energy balance between the induced consumption and the machine performance improvements. The consortium grouped for carrying out this project is composed of a SME (CTEC), two academic institutions (Bundeswehr University Munich and ENSAM) and a Research Centre (ONERA). It groups skills ranging from internal flow analysis in turbomachinery, to flow control or actuators design, manufacturing and characterisations.

A Novel sand control testing facility to evaluate the impact of radial flow regime on screen performance and its verification

Optimum design of the sand control devices in oil sand reservoirs plays a vital role in minimizing the sand production and increasing the reservoir productivity in Steam-Assisted Gravity Drainage (SAGD) operations. Various sand control testing facilities have been developed to evaluate the performance of sand control screens, such as the pre-packed Sand Retention Test (SRT). Current testing apparatuses are based on the linear flow regime. However, fluid flow around SAGD production wells is radial flow, not linear. This study introduces a Full-scale Completion Test (FCT) facility to emulate the radial-flow condition in SAGD wells. Instead of using a disk-shaped screen coupon, this facility utilizes a cylindrical-shaped screen. A couple of tests were carried out to determine the flow uniformity inside the cell and identify the test repeatability. Test results show that flow is distributed uniformly inside the cell, and experiments are repeatable in terms of differential pressures, fines production, and sanding levels. Therefore, this innovative FCT experimental setup and procedure allows a more realistic evaluation of the liner performance by emulating the real SAGD flow regime around the liner. Testing results obtained from the FCT can be used to complement and validate the current testing procedures. These tools can be adopted for an objective custom-design and selection of standalone screens in SAGD.

Analysing the effect of principal stress rotation on railway track settlement by discrete element method

Principal stress rotation induced by moving loads from trains significantly influences railway track settlement accumulation. The stationary cyclic loading commonly adopted to study railway ballast behaviour under repeated train loading cannot fully represent the effects of principal stress rotation, which needs to be properly considered in both laboratory tests and numerical simulations for a better understanding of ballast deformation behaviour. This paper focuses on studying railway ballast deformation behaviour with an emphasis on particle scale interactions under two different loading scenarios – namely, stationary cyclic and moving wheel loading. A ballasted track model consisting of five sleepers was established based on the discrete-element method (DEM) with realistic polyhedron-shaped elements. The numerical model was validated first based on the testing results from a full-scale high-speed railway testing facility at Zhejiang University. Numerical results clearly indicated that moving wheel loading induced larger principal stress rotation than stationed cyclic loading did. Larger principal stress rotation mobilised higher particle rotation and displacement, which further increased particle rearrangements through individual particle rolling and sliding, and potentially could cause accelerated ballast degradation. It is recommended to consider principal stress rotation in ballast settlement predictions to prevent possible underestimation by stationary cyclic loading and its limitations.

Double skin façade integrating semi-transparent photovoltaics: Experimental study on forced convection and heat recovery

Semi-Transparent Photovoltaics (STPV) can be integrated on Double Skin Facades (DSF) to enhance the energy performance of a building. The integrated STPV can simultaneously control solar gains and generate electricity. The optimal operation of the DSF through control of the air flow can enhance the heat extraction from the DSF during heating season, increase the electrical and thermal efficiency of the system, and decrease the heating load of the building. In the present study, the lack of literature in the development of an average Nusselt number correlations for DSF integrating STPV (DSF-STPV) is identified and a new index which corresponds to the heat that is recovered is introduced and is distinguished from the thermal efficiency of the system. Also, in the present study, average Nusselt number correlations for air flow in DSF with STPV are experimentally developed, using a full-scale outdoor test facility. The effect of the incident solar radiation, the wind driven exterior convection and the ambient temperature have been taken into consideration in the development of these convective heat transfer correlations. The properties of the materials of the DSF are also taken into consideration such as the transmittance of the STPV, the PV cell efficiency and the thermal conductance of the glazing. In this process, a new dimensionless number is defined to generalize the results, particularly for the expected operating conditions. The Nusselt number correlations are then used for a sensitivity analysis for different wind speeds and for the assessment of the thermal performance of the system. The heat losses of a typical building in comparison to a building that integrates DSF-STPV can be 20% higher resulting in losses that reach values of 8 W/m2 of façade area. The heat recovery index can reach more than 30% and the total solar utilization efficiency can be between 30% and 77% for different experimental conditions.

Co-simulation and validation of the performance of a highly flexible parametric model of an external shading system

The article presents a validation study of a modelling approach implemented in a numerical script for external louvred shading systems based on an experimental analysis in a full-scale test facility. The model developed to abstract the system was entirely parametric and used co-simulation to predict the indoor air temperature and illuminance levels in two points of the test cell.The calibration of the model of the test facility was carried out using a combination of two methods: automated calibration based on multi-objective optimization with a genetic algorithm and manual calibration. In total, six different configurations of the external shading system with varying complexity were investigated to validate the script. Its performance was assessed using three metrics: the root mean square error, the coefficient of variation of the root mean square error, and the normalized mean bias error.The results showed that the thermal environment was simulated with consistent accuracy for all the cases investigated, predicting air temperatures with an error well within the tolerance of building performance simulation tools and the experimental uncertainty. The daylighting model satisfactorily captured the different dynamics of illuminance peaks and dips, replicating the variations between different configurations, but with a lower degree of accuracy than for the thermal simulations.

Selective light transmission as a leading innovation for solar swimming pool covers

An innovative, extrudable material with the ability to filter the sun’s energy has been developed for the mass manufacture of high performance swimming pool covers. Solar radiation in the visible spectrum (<750 nm) is absorbed by the material so that minimal visible light enters the pool water which inhibits photosynthesis to prevent algae growth. Furthermore, the material has high transmission properties in the near infrared that can be efficiently absorbed by the water allowing for a higher temperature increase compared to a standard non-selective opaque cover. We have developed a model to enable the cover efficiency to convert solar energy to heat a swimming pool, calculated based on the wavelength dependent absorption and transmission properties of the cover. We have validated this model using dedicated full-scale test-facility. Our results demonstrate that a selective transmission cover can increase the absolute heating efficiencies by approximately 12% compared to the fully opaque equivalent.