Sardinia Radio Telescope structural behavior under solar thermal load

Attoli, Alessandro; Stochino, Flavio; Buffa, Franco; Poppi, S.; Serra, G.; Sanna, Giovanna Maria; Cazzani, Antonio

doi:10.1016/j.istruc.2022.03.065

Cited by 8 publications

(5 citation statements)

References 19 publications

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“…14 The fire safety tests were implemented through experimental research [15][16][17] and computational analysis, 18 including Computational Fluid Dynamics (CFD) methods. Numerical analyses involving CFD 19 make it possible to simulate fluid flow processes, allowing the determination of temperature distributions and their thermal analysis for various types of objects, 20,21 including in chimney systems and on adjacent materials. 17,[22][23][24][25] The previous research has also included fire safety analyses of triple-walled steel chimney systems with an air layer along their entire length.…”

Section: Introductionmentioning

confidence: 99%

Fire safety study of a perlite concrete chimney and wooden ceilings used in buildings based on experimental tests and CFD analysis

Drozdzol,

Kowalski,

Kokocinska–Pakiet

et al. 2024

Building Services Engineering Research and Technology

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The operation of fuel-burning heating equipment results in soot build-up in the flues. Its ignition poses a significant fire risk to the building, as the flue temperature can reach 1000°C. Wooden structural elements located near the chimney (ceilings and roof penetrations) are particularly vulnerable. To date, research has focused on the fire safety of wooden ceiling elements. This is where, due to heat radiation from the chimney, wooden elements significantly increase their temperature and become the location of fire initiation in the buildings. The task of chimney designers is to limit the temperatures of heated wooden building components near these structures. The present work analysed a ceramic and concrete chimney with air space with an innovative perlite concrete casing with a dual-function (load-bearing and thermal insulation). Computational Fluid Dynamics (CFD) analyses verified by a full-scale experiment were conducted to evaluate the fire safety of wooden building ceilings. The tests showed that a high level of safety characterised the chimney under study. The maximum temperature of the casing when testing the soot fire reached 38°C, and the wooden elements simulating the ceiling reached 28°C - this result is almost four times better than the chimney standard requirement. Furthermore, a developed CFD model exhibited high accuracy compared to the experimental results and can be used for designing this type of chimney and other research and expert work, such as that performed after fires in buildings originating from the chimney. Practical Application The article describes CFD analyses and tests of an innovative chimney in a perlite-concrete casing. The described research showed the high safety of such a chimney during soot fires. The results obtained can be used to develop changes in standards to improve the safety of chimneys and design safer and more efficient ones. The author’s chimney model and CFD analysis make it possible to determine the temperatures in the chimney during a soot fire. This CFD model allows you to assess the fire safety of the chimney and the building elements located in its vicinity.

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Section: Introductionmentioning

confidence: 99%

Fire safety study of a perlite concrete chimney and wooden ceilings used in buildings based on experimental tests and CFD analysis

Drozdzol,

Kowalski,

Kokocinska–Pakiet

et al. 2024

Building Services Engineering Research and Technology

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“…In order to estimate the dynamic pointing error, the thermal behaviors of radio telescopes under solar radiation have been discussed internationally. Over the past decades, the thermal behaviors of many foreign radio telescopes have been studied overseas via combining finite-element (FE) calculations and relative experiments, including the thermal deformation of the reflector system of the RT-70 radio telescope [9], the thermal design of the quadripod and backup structure of the IRAM 30-m telescope [10], and the thermal analysis of the alidade of the Medicina 32-m telescope and the Sardinia 64-m telescope [11][12][13]. In recent years, the thermal behaviors of several domestic radio telescopes also have been researched in China based on FE analysis and experimental measurements, such as the thermal effects of the alidade of the Nanshan 25-m radio telescope and the Miyun 50-m radio telescope [14,15], the nonuniform temperature and the thermal behavior of the Tianma 65-m radio telescope [16,17], the thermal deformations of the alidade and the reflector system of WRT70 [18,19].…”

Section: Introductionmentioning

confidence: 99%

Estimation of Pointing Errors of Large Radio Telescopes under Solar Radiation Based on Digital Twin

Wei,

Kong,

Wang

et al. 2024

Preprint

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The pointing accuracy of large radio telescopes is affected by antenna structure errors, installation errors, servo errors, gravity, and varying environmental factors. It is hard to estimate the pointing error of radio telescopes under solar radiation via the traditional multi-parameter static pointing models, due to the time-varying characteristics of the dynamic pointing error. There is still no effective way to estimate the dynamic pointing error of large radio telescopes under solar radiation up to now. To estimate the dynamic pointing error of large radio telescopes under solar radiation, a new way based on digital twin(DT) is tried in this paper. The operational framework of the DT system of large radio telescopes is introduced first. Then, the Wuqing 70-m radio telescope(WRT70) is taken as the research object, the digital models of which are created. Finally, the reliability of the WRT70's DT system is verified and the dynamic pointing error of WRT70(staying at the position of the elevation angle of 90° and the azimuth angle of 180°) on two sunny days in different seasons is estimated by the created DT system. The research results show that the pointing error of large radio telescopes under solar radiation fluctuates greatly and the seasonal differences are very striking. The maximum elevation pointing error of WRT70 under solar radiation around the winter solstice is over 40 arcsec, which should never be ignored. The way is feasible to estimate the dynamic pointing error of large radio telescopes staying at a specific position under solar radiation via constructing a DT system in this paper, but it is not yet able to estimate effectively the dynamic pointing error of large radio telescopes being in action. It is expected to establish a dynamic pointing error model and calibrate the dynamic pointing errors of large radio telescopes being in action by DT technology in the future.

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“…Tese pointing requirements demand an understanding of additional factors beyond the conventional considerations such as encoder errors and axis geometry errors. Tese factors include deformation of the alidade, backup structure, and subrefector support legs, caused by gravity, temperature fuctuations, and wind disturbance, as well as azimuth track local unevenness [5][6][7][8]. A model which investigates the relationship between the track unevenness and radio telescope pointing through the interaction between the track and the alidade (track-alidade model for short) was introduced by Constantikes [9] and Xue et al [10].…”

Section: Introductionmentioning

confidence: 99%

Measuring Track-Related Pointing Errors on the Nanshan Radio Telescope with an Optical Pointing Telescope

Yuan,

Liu,

Wang

2024

Advances in Astronomy

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The need for precise radio telescope pointing has driven great attention to investigating the effect of antenna local deformation or irregularity, such as unevenness in the azimuth track. Although the track-alidade interaction model is commonly used to investigate the pointing effect of track unevenness (such as the works on DSN 34 m antennas and the Green Bank Telescope), few experiments have been done to test the effectiveness of this model independently from the overall pointing model. To address this issue, a method utilizing an optical pointing telescope (OPT) for determining the impact of track unevenness on pointing is proposed. This method uses a group of reference pointing data collected by an OPT mounted at the bottom of the antenna alidade to extract the twist effect of the alidade from the radio telescope pointing data, thus compared with the predicted twist by the track-alidade model. This method was applied to the 26 meter Nanshan Radio Telescope (NSRT 26 m), achieving good agreement with the model-predicted values.

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Sardinia Radio Telescope structural behavior under solar thermal load

Cited by 8 publications

References 19 publications

Fire safety study of a perlite concrete chimney and wooden ceilings used in buildings based on experimental tests and CFD analysis

Fire safety study of a perlite concrete chimney and wooden ceilings used in buildings based on experimental tests and CFD analysis

Estimation of Pointing Errors of Large Radio Telescopes under Solar Radiation Based on Digital Twin

Measuring Track-Related Pointing Errors on the Nanshan Radio Telescope with an Optical Pointing Telescope

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