Installation Of Arrays Research Articles

Industrial application of a low-cost structural health monitoring system in large-scale airframe tests

A small, novel, integrated SHM system has been deployed during full-scale testing of a wing fatigue test for several weeks and a fuselage pressurisation test for several months. Complementary NDE measurement techniques were combined, with inputs from visible and infrared optical sensors, as well as resistance strain gauges. Sensor units were deployed at regions of interest and integrated board computers permitted near real-time data processing. The outputs were full-field measurement datasets from digital image correlation and thermoelastic stress analysis systems. Changes in these datasets in the regions of interest were successfully quantified using orthogonal decomposition and were indicative of changes in the condition of the structure. The results from these case studies demonstrate that this system can be successfully deployed in spatially restricted areas within airframe structures to monitor crack growth. The low cost and small footprint of the system presents the opportunity for installation of arrays of similar sensors for both test and in-service data collection. Near real-time data processing would allow timely reporting to service engineers, informing maintenance or operational decisions.

On-Grid Solar Traction System

World Railways is making significant progress in introducing high-speed trains to fulfil the increasing demands of the traveling public. Massive energy is needed for electric railroads. Many railroads operate their specialized power plants. An energy-storage grid-tied photovoltaic solar plant has been proposed as a strategy to boost the capacity of the rail network grid connection and enable the railway to become self-sufficient. To use the ballast-less rails as energy transporters, The current plan calls for installing solar panels along an HS train network. Ballast-free tracks require very little upkeep, and the space between them provides plenty of surface area for the installation of PV module arrays to harvest solar energy. This generated energy will feed into the main power line by using the concept of an on-grid solar system this energy is not more in numbers to drive the entire traction system, but it helps a lot. From this project we have developed hybrid parallel power sharing for the railway network, under this project the current will be shared in the main power line by matching the grid frequency and voltages. The primary power is solar when it can generate enough electricity. Still, in an abnormal condition, like in the absence of sunlight, the main power continuously feeds electricity without disturbing the traction system.

CFD Assessment of Car Park Ventilation System in Case of Fire Event

This scientific article presents the results of computational fluid dynamics (CFD) simulations conducted using OpenFOAM to evaluate the effectiveness of a jet fan ventilation system in managing the dispersion of smoke resulting from a car fire incident within an underground car park spanning a total area of 21,670 m2, situated in Tabriz, Iran. The primary objective of the study is to determine the velocity fields and evaluate visibility conditions within a 10 m radius to gauge the efficiency and effectiveness of the system. The study employs a smoke concentration production rate of 5.49 × 10−4 kg/m3s for simulations involving fire scenarios. A total of 17 fire scenarios are examined, each extending 30 m in all directions from the initial location. The research findings demonstrate that the placement of jet fan components plays a significant role in the system’s efficiency, with fans positioned near the ceiling leading to back-layering. To mitigate this issue, the recommended design solution involves the strategic installation of multiple jet fan arrays in specific zones with the addition of 10 extra jet fans, effectively curbing lateral smoke dispersion. Furthermore, the analysis of air flow rates shows that when jet fans direct an excessive airflow towards the exhaust shafts (which have a designated flow rate of 22.5 m3/s), recirculating flows occur, leading to the dispersion of smoke throughout the car park. Consequently, the utilization of low-velocity jet fans (11.2 m/s) proves to be more effective in clearing smoke compared to high-velocity jet fans (22.3 m/s). The study also emphasizes the importance of optimal positioning of supply and exhaust shafts to achieve effective smoke control, highlighting the need for placing them on opposite walls or minimizing airflow turns. Additionally, the research underscores the significance of fire resistance in jet fan units, as their failure during fire incidents can have severe consequences.

Analyzing and evaluating floating PV systems in relation to traditional PV systems

The various benefits of floating photovoltaic technology, a relatively new kind of energy generation, have piqued the interest of many people (FPVT). FPVT technology not only helps to lessen water loss due to evaporation, but it also helps to increase energy production. Science can't progress without the analysis of mechanical and electrical systems. Many researchers have looked at FPVT systems from different angles. This article undertakes a logical investigation and provides a thorough summary of the state of the art, elaborating on the numerous features and components of FPVT systems as a means of producing electricity. The advantages and disadvantages of each type have been compared in detail. A common way of capturing solar energy for use in electrical generation is the installation of solar arrays on the roof of a structure. However, although most homes only need 5–20 kW, most enterprises require 100 kW or more. On average, floating solar panels produce 11 percent more energy than their ground-based counterparts. Approximately 40% of the water in open reservoirs is lost to evaporation, according to studies. Covering only 30% of the water's surface can reduce evaporation by 49%. At 104 GW, the solar panel market will see a compound annual growth rate of 6%. Global photovoltaic capacity climbed by 27% in 2018, reaching 512 GW. This represents about 55% of the total capacity. This study also predicts that the FPVT system will help spur a 7.38 percent increase in solar technology, which is equal to 485.4 GW of additional installed electricity around the world.

A Post-Synthetic Modification Strategy for the Preparation of Homooligomers of 3-Amino-1-methylazetidine-3-carboxylic Acid

AbstractPost-synthetic modification is a powerful technique allowing access to noncanonical peptide derivatives in a selective manner, but it has not so far been applied for the installation of multiple arrays of modified side chains. Here, we use this approach in solution phase to prepare short N- and C-capped homooligomers of 3-amino-1-methylazetidine-3-carboxylic acid with all the azetidine side chain functions in free amine form. The key step is the multiple reductive amination reaction of the corresponding post-synthetically deprotected secondary amines.

Continuous monitoring with a permanently installed high-resolution ultrasonic phased array

High-resolution defect detection is an integral part of non-destructive testing (NDT). Ultrasonic array transducers have been developed to respond to this need and provide high-resolution images for such applications. At present, high-resolution imaging is achieved by ultrasonic array design, such as enhanced transducer materials, and optimised element geometry to fulfil inspection requirements and miniaturise imaging artefacts, etc. This paper presents a novel ultrasonic array and controller system design strategy that can miniaturise the array and reduce manufacturing cost of the entire array system. This then enables the permanent or semi-permanent installation of arrays onto structures and long-term continuous structural health monitoring (SHM). The array geometry is designed as a compromise between the required imaging performance for the desired application and the fabrication cost for permanent installation. A prototype array transducer is constructed from piezoceramic elements bonded to a flexible printed circuit (FPC) substrate and then permanently installed on example structures to demonstrate long-term monitoring. Improved long-term sensitivity to defect growth is achieved by applying a compensation strategy for velocity and phase changes with temperature. Results show that a 5 MHz, 18-element prototype array can detect changes as small as 0.1 mm in the diameter of a side-drilled hole (SDH) defect after 3 months of continuous monitoring.

Comparing single-station 6C measurements and array measurements for seismic microzonation in Munich, Germany

SUMMARY The essential goal of seismic microzonation is the estimation of the shallow velocity structure in order to characterize the local earthquake shaking characteristics. This is of special importance in densely inhabited areas with unfavourable soil conditions. The common approach is the analysis of ambient noise array data using frequency–wavenumber (FK) or spatial autocorrelation (SPAC) techniques. However, the installation of arrays is difficult, especially within urban environments, making single-station approaches more desirable. In this study, we directly compare the recently developed approach of velocity estimation using single-station six-component (6C) measurements, combining three translational and three rotational motions, with the established methods of FK and SPAC analysis. We conduct measurements in Munich’s inner city using a geophone array and an iXblue blueSeis-3A rotational motion sensor together with a Nanometrics Trillium Compact Seismometer, respectively. From the array data, as well as from the 6C data, Love and Rayleigh dispersion curves are estimated and further inverted for 1-D P- and S-wave velocity profiles. We find that all methods give similar results, indicating the potential of the novel 6C approach. Furthermore, adding horizontal-to-vertical spectral ratios enables the inversion for structures at greater depth and increases the resolution of the velocity structure. In addition, we test different array geometries to evaluate the influence of the sensor configuration on the results. As a last step, we compare the estimated velocity models to lithologic profiles and find an overall positive correlation, which supports our inversion results.

Optimising Electrical Power Supply Sustainability Using a Grid-Connected Hybrid Renewable Energy System—An NHS Hospital Case Study

This study focuses on improving the sustainability of electrical supply in the healthcare system in the UK, to contribute to current efforts made towards the 2050 net-zero carbon target. As a case study, we propose a grid-connected hybrid renewable energy system (HRES) for a hospital in the south-east of England. Electrical consumption data were gathered from five wards in the hospital for a period of one year. PV-battery-grid system architecture was selected to ensure practical execution through the installation of PV arrays on the roof of the facility. Selection of the optimal system was conducted through a novel methodology combining multi-objective optimisation and data forecasting. The optimisation was conducted using a genetic algorithm with two objectives (1) minimisation of the levelised cost of energy and (2) CO2 emissions. Advanced data forecasting was used to forecast grid emissions and other cost parameters at two year intervals (2023 and 2025). Several optimisation simulations were carried out using the actual and forecasted parameters to improve decision making. The results show that incorporating forecasted parameters into the optimisation allows to identify the subset of optimal solutions that will become sub-optimal in the future and, therefore, should be avoided. Finally, a framework for choosing the most suitable subset of optimal solutions was presented.

Performance analysis of integrated solar heat pump VRF system for the low energy building in Mediterranean island

Cyprus is a heavily energy-receiving country, importing over 90% of its energy demand. Since heating and cooling of buildings account for roughly half of the yearly global energy consumptions, energy efficiency in cooling/heating systems, and devising renewable energy AC systems could contribute to significant alleviation in the energy situation of Cyprus. High levels of solar radiation are available in Cyprus and any attempt to devise or implement a solar AC system with feasible costs could be worthwhile. In this paper, energy performance and power generation of a variable refrigerant flow (VRF) heat pump system integrated with PV technology in a 5-story residential building in Cyprus are investigated. The yearly horizontal radiation intensity in the selected locations ranges from 1,784 to 1,882 kWh/m2. Yearly VRF power consumption ranges from 14,005 to 18,710 kWh and a PV array with a total capacity of 13 kW can generate between 23,200 and 23,650 kWh annually. PV arrays satisfy 126–166% of the annual VRF energy demand. Moreover, the installation of the PV system reduces approximately 14 tons of CO2 each year. Finally, an economic feasibility study indicates that the installation of PV arrays for this application in all investigated locations is financially profitable and for a 20-year investment period, the net present value of the project would vary from 4,843 to 13,355 $.

Economic Assessment of a PV Hybridized Linear Fresnel Collector Supplying Air Conditioning and Electricity for Buildings

The present study evaluates the potential upgrade of a Linear Fresnel Reflector (LFR) collector at the Cyprus Institute (CyI) with photovoltaics via the calculation of the Levelized Cost Of Heat (LCOH). For over 4 years the collector has been supplying heating and cooling to the Novel Technologies Laboratory (NTL) of the Cyprus Institute (CyI). Extensive measurements have been carried out both on the LFR and NTL to render real numbers in the computations. This hybridization would be undertaken with the installation of PV arrays under mirrors, so that the collector is able to either reflect direct radiation to the receiver to process heat or to produce electricity directly in the built environment. The main objective is the decrease of the LCOH of Linear Fresnel collectors, which hinders their wider deployment, while air conditioning demand is globally booming. The results show that the LCOH for a small LFR to supply air conditioning is high, c€25.2–30.1 per kWh, while the innovative PV hybridization proposed here decreases it. The value of the study resides in the real data collected in terms of thermal efficiency, operation, and maintenance.

Performance and Optimization of Commercial Solar PV and PTC Plants

Installation of solar PV arrays at utility scale is gaining popularity nowadays because of the significant reduction in the cost of components as well as the global push towards clean energy. Solar PV plants along with Parabolic Trough Collector Solar thermal plants has the highest potential among the available Renewable Energy (RE) technologies existing in the world. The objective of this paper is to optimize the performance of commercial Solar PV and PTC power plant for a potential location and hence to arrive on a most feasible configuration for the site. A representative site located in the Abudhabi region of UAE considered for the study. This paper also details on the annual performance of the proposed plant along with its technical aspects. PVSYST 6.7.7 and SAM software is used to design the optimal size and its specifications of a 100MW PV grid connected system at Abu Dhabi (UAE) region. The design and arrangements of the system verified using simulation results. The annual energy generated from the designed utility-scale solar PV plant from PVSYST 6.7.7 calculated as 161198MWh/year with a performance ratio (PR) of 74.8% per year where as for PTC it has calculated as 157152MWh/year by using SAM. The STC (Standard Testing Condition) for the specification of PV modules are normalized operating conditions when testing the module. Design parameters such as module orientation, array yield, reference yield, final yield, global horizontal irradiation (GHI), and ambient temperature and loss factors evaluated. To evaluate the economic feasibility of proposed plant, the levelized cost of electricity (LCOE) is determined as $0.04404/kwh for Solar PV and as $0.01533/kwh for PTC, which is used to calculate lifecycle cost and energy production.

Underwater Terrain Positioning Method Using Maximum a Posteriori Estimation and PCNN Model

Conventional underwater navigation and positioning methods for Autonomous Underwater Vehicles (AUVs) either require the installation of acoustic arrays, which make AUVs less independent, or result in cumulative errors. This paper proposes an Underwater Terrain Positioning Method (UTPM) using Maximum a Posteriori (MAP) estimation and a Pulse Coupled Neural Network (PCNN) model for highly accurate navigation by AUVs. The PCNN model is used as a secondary discriminant to effectively identify pseudo-anchor points in flat terrain feature areas and to find the true positioning point, which significantly improves the matching positioning accuracy in these areas. Simulation results show that the proposed method effectively corrects Inertial Navigation System (INS) cumulative errors and has high matching positioning accuracy, which satisfy the requirements of AUV underwater navigation and positioning.

Tidal stream resource assessment uncertainty due to flow asymmetry and turbine yaw misalignment

The majority of tidal energy convertors (TECs) currently under development are of a non-yawing horizontal axis design. However, most energetic regions that have been identified as candidate sites for installation of TEC arrays exhibit some degree of directional and magnitude asymmetry between incident flood and ebb flow angles and velocities, particularly in nearshore environments where topographic, bathymetric and seabed frictional effects and interactions are significant. Understanding the contribution of directional and magnitude asymmetry to resource power density along with off axis rotor alignment to flow could influence site selection and help elucidate optimal turbine orientation. Here, 2D oceanographic model simulations and field data were analysed to investigate these effects at potential deployment locations in the Irish Sea; an energetic semi-enclosed shelf sea region. We find that observed sites exhibiting a high degree of asymmetry may be associated with a reduction of over 2% in annual energy yield when deployment design optimisation is ignored. However, at the majority of sites, even in the presence of significant asymmetry, the difference is <0.3%. Although the effects are shown to have less significance than other uncertainties in resource assessment, these impacts could be further investigated and quantified using CFD and 3D modelling.

Ambient noise tomography reveals upper crustal structure of Icelandic rifts

The structure of oceanic spreading centres and subsurface melt distribution within newly formed crust is largely understood from marine seismic experiments. In Iceland, however, sub-aerial rift elevation allows both accurate surface mapping and the installation of large broadband seismic arrays. We present a study using ambient noise Rayleigh wave tomography to image the volcanic spreading centres across Iceland. Our high resolution model images a continuous band of low seismic velocities, parallelling all three segments of the branched rift in Iceland. The upper 10 km contains strong velocity variations, with shear wave velocities 0.5 km s−1 faster in the older non-volcanically active regions compared to the active rifts. Slow velocities correlate very closely with geological surface mapping, with contours of the anomalies parallelling the edges of the neo-volcanic zones. The low-velocity band extends to the full 50 km width of the neo-volcanic zones, demonstrating a significant contrast with the narrow (8 km wide) magmatic zone seen at fast spreading ridges, where the rate of melt supply is similarly high. Within the seismically slow rift band, the lowest velocity cores of the anomalies occur above the centre of the mantle plume under the Vatnajökull icecap, and in the Eastern Volcanic Zone under the central volcano Katla. This suggests localisation of melt accumulation at these specific volcanic centres, demonstrating variability in melt supply into the shallow crust along the rift axis. Shear velocity inversions with depth show that the strongest velocity contrasts are found in the upper 8 km, and show a slight depression in the shear velocity through the mid crust (10–20 km) in the rifts. Our model also shows less intensity to the slow rift anomaly in the Western Volcanic Zone, supporting the notion that rift activity here is decreasing as the ridge jumps to the Eastern Volcanic Zone.

Modelling the sensitivity of suspended sediment profiles to tidal current and wave conditions

Seawater turbidity due to suspended particulate material (SPM) is an important property of a marine ecosystem, determining the underwater light environment and many aspects of biological production and ecology. SPM concentrations are largely determined by patterns of sediment resuspension from the seabed due to shear stress caused by waves and currents. Hence planning for the construction of large scale offshore structures which will alter regional hydrodynamics needs to consider the consequences for SPM concentrations. Here we develop a one-dimensional (vertical) model of SPM dynamics which can be used to scope the effects of changes in wave and tidal current properties at a site. We implement the model for a number of sites off the east coast of Scotland where we have extensive data sets to enable numerical parameter optimisation. The model performs well at simulating fluctuations in turbidity varying from flood-ebb tidal cycles, spring-neap cycles, storm wave events, and an annual cycle of SPM concentration which is attributed to seasonal consolidation of seabed sediments. Sensitivity analysis shows that, for the range of seabed sediment types in the study (water depth 16–50 m; mud content 0.006–0.380 proportion by weight), relatively large (50%) attenuations of tidal current speed are required to produce changes in water column turbidity which would be detectable by observations given the variability in measurements. The model has potential for application to map the large scale sensitivity of turbidity distributions to the installation of wave and tidal energy extraction arrays.

Boosting Blue Growth in a Mild Sea: Analysis of the Synergies Produced by a Multi-Purpose Offshore Installation in the Northern Adriatic, Italy

In the near future, the oceans will be subjected to a massive development of marine infrastructures, including offshore wind, tidal and wave energy farms and constructions for marine aquaculture. The development of these facilities will unavoidably exert environmental pressures on marine ecosystems. It is therefore crucial that the economic costs, the use of marine space and the environmental impacts of these activities remain within acceptable limits. Moreover, the installation of arrays of wave energy devices is still far from being economically feasible due to many combined aspects, such as immature technologies for energy conversion, local energy storage and moorings. Therefore, multi-purpose solutions combining renewable energy from the sea (wind, wave, tide), aquaculture and transportation facilities can be considered as a challenging, yet advantageous, way to boost blue growth. This would be due to the sharing of the costs of installation and using the produced energy locally to feed the different functionalities and optimizing marine spatial planning. This paper focuses on the synergies that may be produced by a multi-purpose offshore installation in a relatively calm sea, i.e., the Northern Adriatic Sea, Italy, and specifically offshore Venice. It analyzes the combination of aquaculture, energy production from wind and waves, and energy storage or transfer. Alternative solutions are evaluated based on specific criteria, including the maturity of the technology, the environmental impact, the induced risks and the costs. Based on expert judgment, the alternatives are ranked and a preliminary layout of the selected multi-purpose installation for the case study is proposed, to further allow the exploitation of the synergies among different functionalities.

Extending solar potential analysis in buildings to vertical facades

The assessment of local photovoltaic (PV) potential plays a critical role in the development of planning policies and financing schemes for the successful deployment of PV systems in cities. Considering the significant area available on facades in modern urban landscapes, the solar potential analysis at the local or municipal scale should be extended to take into account the irradiation on vertical walls. Starting from three different sets of information of a site, solar radiation model for roofs, ground and facades, 3D buildings model and a DSM derived from airborne LiDAR data, a methodology was developed in a GIS environment in order to fuse the datasets and allow for spatio-temporal analysis for solar energy quests. The resultant 3D database enables spatial visualization of the answers to the most interesting questions regarding new solar energy systems on buildings. The GIS database can be used as a tool to support municipal/local decision planners since statistics for the solar potential of each building can be easily inspected. In order to optimize solar collection, this system is particularly suited to identify which parts (roofs and/or facades) of a building are more favorable for the installation of solar arrays as well as the area available for the installation.

Will we exceed 50% efficiency in photovoltaics?

Solar energy is the most abundant and reliable source of energy we have to provide for the multi-terawatt challenge we are facing. Although huge, this resource is relatively dispersed. High conversion efficiency is probably necessary for cost effectiveness. Solar cell efficiencies above 40% have been achieved with multijunction (MJ) solar cells. These achievements are here described. Possible paths for improvement are hinted at including third generation photovoltaics concepts. It is concluded that it is very likely that the target of 50% will eventually be achieved. This high efficiency requires operating under concentrated sunlight, partly because concentration helps increase the efficiency but mainly because the cost of the sophisticated cells needed can only be paid by extracting as much electric power form each cell as possible. The optical challenges associated with the concentrator optics and the tools for overcoming them, in particular non-imaging optics, are briefly discussed and the results and trends are described. It is probable that optical efficiency over 90% will be possible in the future. This would lead to a module efficiency of 45%. The manufacturing of a concentrator has to be addressed at three levels of integration: module, array, and photovoltaic (PV) subfield. The PV plant as a whole is very similar than a flat module PV plant with two-axes tracking. At the module level, the development of tools for easy manufacturing and quality control is an important topic. Furthermore, they can accommodate in different position cells with different spectral sensitivities so complementing the effort in manufacturing MJ cells. At the array level, a proper definition of the nameplate watts, since the diffuse light is not used, is under discussion. The cost of installation of arrays in the field can be very much reduced by self aligning tracking control strategies. At the subfield level, aspects such as the self shadowing of arrays causes the CPV subfields to be sparsely packed leading to a ground efficiency, in the range of 10%, that in some cases will be below that of fixed modules of much lower cell efficiency. All this taken into account, High Concentration PV (HCPV) has the opportunity to become the cheapest of the PV technologies and beat the prevalent electricity generation technologies. Of course the way will be paved with challenges, and success is not guaranteed.

An experimental investigation simulating flow effects in first generation marine current energy converter arrays

At present a small number of full-scale marine current energy converters are undergoing sea trials to demonstrate commercial viability of the technology. In order to provide meaningful quantities of electrical power to the grid, the next phase in the development of the technology will be the installation and operation of farms or arrays composed of multiple devices. As most tidal current sites are bi-directional and with bathymetry constraints, array layouts will necessarily take the form of highly optimized geometric configurations with reduced lateral inter-device spacing. This work discusses the concept of array layouts and proposes an appropriate and clear classification that can aid developers in understanding how arrays operate. This classification is supported by experimental studies conducted using several arrangements of multiple actuator disks to simulate early generation marine current energy converter arrays. The work presents quantification of the flow field around a 2-row array, device/device interaction as well as a study of the structure of the far wake region where subsequent devices could be installed. The results highlight an optimal lateral spacing between devices where, under certain conditions flow can be accelerated between a pair of rotor disks. For the work presented here this accelerated region of flow possessed 22% more kinetic energy than the flow far upstream with no measurable negative effect upon the 2 actuator disks. This enhanced flow speed gives rise to the counterintuitive notion of a downstream row of devices producing more power than the upstream row. This will lead to a synergistic effect whereby an array of devices can generate more power than an equivalent number of isolated machines.

Optimizing the Migration to Future-Generation Passive Optical Networks (PON)

We study the upgrading problem of existing Passive Optical Networks (PONs) that need to increase their capacity at different points in time. Our method upgrades line rates and migrates network services over new wavelength channels based on increasing traffic demand and cost constraints. Our method minimizes capital expenses and system disruptions, while ensuring effective resource usage. Our multistep model uses Mixed Integer Linear Program (MILP) formulations whose cost parameters are set by a pricing policy. We evaluate the PON upgrade through installation of single-wavelength transceivers or multiple-wavelength arrays of transceivers. We consider a typical case study, which is solved using CPLEX. Illustrative examples demonstrate the attractive properties of our method.