Article
Engineering, Civil
Bingchao Zhang, Lei Zhou, Tim K. T. Tse, Liangzhu Wang, Jianlei Niu, Cheuk Ming Mak
Summary: The study introduced a new method called extended SPOD (ESPOD) by combining the extended proper orthogonal decomposition (POD) with spectral POD (SPOD) to correlate flow structures with surface pressure. The method was validated through a case study on a high-rise building and revealed the main mechanisms of wind forces. Phase synchronization used in ESPOD was an effective criterion for distinguishing multiple physical mechanisms at the same frequency. Compared to velocity-based approaches, the pressure-based approach captured wind force fluctuations more completely without distorting velocity modes too much.
JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS
(2023)
Article
Construction & Building Technology
Bingchao Zhang, Hong Hu, Hideki Kikumoto, Ryozo Ooka
Summary: This study uses spectral proper orthogonal decomposition (SPOD) to analyze the impact of turbulence on natural ventilation in a building. The results show that turbulence produces two main ventilation routes: cross ventilation in the low-frequency region and single-sided ventilation in the high-frequency region. Additionally, the installation location of window casements has a significant influence on turbulence-induced ventilation.
BUILDING AND ENVIRONMENT
(2022)
Article
Engineering, Civil
Ning Zhao, Yan Jiang, Liuliu Peng, Xiaowei Chen
Summary: This study proposes a POD interpolation-enhanced approach to expedite the simulation of nonstationary wind fields by reducing computational cost and speeding up the summing of cosine functions.
JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS
(2021)
Article
Green & Sustainable Science & Technology
Jae Sang Moon, Lance Manuel
Summary: This study proposes using POD to explore reduced-order wake turbulence fields. Important modes organized by eigenvalues are evaluated using statistical summaries extracted from large eddy simulation (LES) of wind turbine wakes. Different patterns in turbulence energy are observed, with CPSD-based POD found to be more efficient in capturing dynamic characteristics and spatial patterns in waked wind fields using a small number of modes.
JOURNAL OF RENEWABLE AND SUSTAINABLE ENERGY
(2021)
Article
Mechanics
Zihao Wang, Guiyong Zhang, Teizhi Sun, Huakun Huang
Summary: This study explores challenges in multivariate modal decomposition and introduces two novel data-driven modal analysis methods, SIMPOD and TIMPOD, to address the problem of inconsistent physical modes in POD.
Article
Chemistry, Multidisciplinary
Yi Su, Jin Di, Jinzhe Li, Fan Xia
Summary: Due to the complex and diverse structural forms of large-span roof structures, universal shape coefficients cannot be defined, making wind tunnel tests necessary. However, the limited number of test measurement points poses limitations in the study of wind loads on large-span roof structures. In this study, the proper orthogonal decomposition (POD) method is used to reconstruct the wind pressure field of a large-span folded-plate roof based on wind tunnel pressure test results. Different interpolation methods are employed to predict the wind pressure at characteristic points, and the accuracy and feasibility of the POD method in reconstructing and predicting the wind pressure field are analyzed. The results show that the order of selected structural eigenmodes and the spatial position of the predicted point affect the reconstruction accuracy of the wind pressure field. Different interpolation methods can achieve ideal results for predicting the wind pressure of an unknown point.
APPLIED SCIENCES-BASEL
(2022)
Article
Thermodynamics
Federico Rulli, Stefano Fontanesi, Alessandro d'Adamo, Fabio Berni
Summary: Experimental techniques such as particle image velocimetry provide strong technical support for analyzing the spatial and temporal evolution of flow fields in internal combustion engines, particularly focusing on cyclic variations. In recent years, methods utilizing proper orthogonal decomposition to analyze cycle-to-cycle variability have become increasingly important in engine development.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2021)
Article
Acoustics
L. V. Pereira, T. G. Ritto
Summary: This study combines POD and SOD to identify rub-impact faults in gas turbines, showing that both methods can effectively recognize pattern changes. The proposed methodology can monitor the evolution of modal component patterns and support engineers in decision-making.
JOURNAL OF SOUND AND VIBRATION
(2021)
Article
Computer Science, Interdisciplinary Applications
Michel Onori, Nicholas J. Hills
Summary: This paper presents a Reduced Order Modelling (ROM) approach for turbulent flow in a rotor-stator cavity commonly found in aircraft engine secondary air systems. The method uses Proper Orthogonal Decomposition (POD) with data from Large Eddy Simulations (LES) to predict turbulence phenomena accurately, introducing two novel techniques in the process.
COMPUTERS & FLUIDS
(2021)
Article
Engineering, Marine
Zihao Wang, Guiyong Zhang, Huakun Huang, Hao Xu, Tiezhi Sun
Summary: This paper proposes the use of Joint POD (JPOD) as a promising fluid mechanics analysis tool to extract multi-variable features of cavitation flow. JPOD increases the reconstruction error slightly but strengthens the correlations between multivariate variables in the flow field. The successful combination of joint representation and POD algorithm demonstrates its potential as an optimization and standardization method for traditional modal decomposition algorithms, with broad application prospects in the field of modal decomposition.
Article
Multidisciplinary Sciences
A. B. Albidah, W. Brevis, V. Fedun, I. Ballai, D. B. Jess, M. Stangalini, J. Higham, G. Verth
Summary: The study demonstrates the successful identification of sausage and kink modes in a sunspot umbra using a combination of POD and DMD techniques, providing new insights into solar observations.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2021)
Article
Acoustics
Michael A. Marshall
Summary: This study aims to clarify the conditions under which the POMs of a linear, undamped, and unforced mechanical system converge to the system's LVMs. It provides a rigorous proof of convergence that shows increasing both the sampling rate and the duration of the sampling is necessary, rather than just increasing the sampling rate.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Mechanics
Marc Olbrich, Markus Baer, Kilian Oberleithner, Sonja Schmelter
Summary: This study investigates different cases of slug flow in horizontal pipes to find statistical characteristics of the slugs in time and space, including slug frequencies, averaged slug body length, and an energy representation. The use of snapshot proper orthogonal decomposition with an additional mode coupling algorithm provides accurate and reliable characterization of the slug flow patterns.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2021)
Article
Engineering, Mechanical
Wei Zhou, Y. F. Xu
Summary: This study investigates the use of Proper Orthogonal Modes (POMs) of guided wavefields for damage identification in beam-like structures. The continuous wavelet transform is employed to enhance local anomalies and suppress global trends, and an adaptive truncation technique is used to determine significant POMs for damage identification. Numerical and experimental investigations verify the accuracy and noise-robustness of the proposed method for identifying the location and extent of damage in beam-like structures.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Computer Science, Interdisciplinary Applications
Akhil Nekkanti, Oliver T. Schmidt
Summary: An algorithm based on spectral proper orthogonal decomposition (SPOD) is developed to reconstruct flow data in compromised or missing regions. The algorithm utilizes the temporal and spatial correlation of the SPOD modes to fill in the gaps. The method is demonstrated on two examples and achieves higher data recovery rates compared to established methods.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Green & Sustainable Science & Technology
Cameron Bracken, Nathalie Voisin, Casey D. Burleyson, Allison M. Campbell, Z. Jason Hou, Daniel Broman
Summary: This study presents a methodology and dataset for examining compound wind and solar energy droughts, as well as the first standardized benchmark of energy droughts across the Continental United States (CONUS) for a 2020 infrastructure. The results show that compound wind and solar droughts have distinct spatial and temporal patterns across the CONUS, and the characteristics of energy droughts are regional. The study also finds that compound high load events occur more often during compound wind and solar droughts than expected.
Article
Green & Sustainable Science & Technology
Ning Zhang, Yanghao Yu, Jiawei Wu, Ershun Du, Shuming Zhang, Jinyu Xiao
Summary: This paper provides insights into the optimal configuration of CSP plants with different penetrations of wind power by proposing an unconstrained optimization model. The results suggest that large solar multiples and TES are preferred in order to maximize profit, especially when combined with high penetrations of wind and photovoltaic plants. Additionally, the study demonstrates the economy and feasibility of installing electric heaters (EH) in CSP plants, which show a linear correlation with the penetration of variable energy resources.
Article
Green & Sustainable Science & Technology
M. Szubel, K. Papis-Fraczek, S. Podlasek
Article
Green & Sustainable Science & Technology
J. Silva, J. C. Goncalves, C. Rocha, J. Vilaca, L. M. Madeira
Summary: This study investigated the methanation of CO2 in biogas and compared two different methanation reactors. The results showed that the cooled reactor without CO2 separation achieved a CO2 conversion rate of 91.8%, while the adiabatic reactors achieved conversion rates of 59.6% and 67.2%, resulting in an overall conversion rate of 93.0%. Economic analysis revealed negative net present worth values, indicating the need for government monetary incentives.
Article
Green & Sustainable Science & Technology
Yang Liu, Yonglan Xi, Xiaomei Ye, Yingpeng Zhang, Chengcheng Wang, Zhaoyan Jia, Chunhui Cao, Ting Han, Jing Du, Xiangping Kong, Zhongbing Chen
Summary: This study investigated the effect of using nanofiber membrane composites containing Prussian blue-like compound nanoparticles (PNPs) to relieve ammonia nitrogen inhibition of rural organic household waste during high-solid anaerobic digestion and increase methane production. The results showed that adding NMCs with 15% PNPs can lower the concentrations of volatile fatty acids and ammonia nitrogen, and increase methane yield.
Article
Green & Sustainable Science & Technology
Zhong Ge, Xiaodong Wang, Jian Li, Jian Xu, Jianbin Xie, Zhiyong Xie, Ruiqu Ma
Summary: This study evaluates the thermodynamic, exergy, and economic performance of a double-stage organic flash cycle (DOFC) using ten eco-friendly hydrofluoroolefins. The influences of key parameters on performance are analyzed, and the advantages of DOFC over single-stage type are quantified.
Article
Green & Sustainable Science & Technology
Nicolas Kirchner-Bossi, Fernando Porte-Agel
Summary: This study investigates the optimization of power density in wind farms and its sensitivity to the available area size. A novel genetic algorithm (PDGA) is introduced to optimize power density and turbine layout. The results show that the PDGA-driven solutions significantly reduce the levelized cost of energy (LCOE) compared to the default layout, and exhibit a convex relationship between area and LCOE or power density.
Article
Green & Sustainable Science & Technology
Chunxiao Zhang, Dongdong Li, Lin Wang, Qingpo Yang, Yutao Guo, Wei Zhang, Chao Shen, Jihong Pu
Summary: In this study, a novel reversible liquid-filled energy-saving window that effectively regulates indoor solar radiation heat gain is proposed. Experimental results show that this window can effectively reduce indoor temperature during both summer and winter seasons, while having minimal impact on indoor illuminance.
Article
Green & Sustainable Science & Technology
Alessandro L. Aguiar, Martinho Marta-Almeida, Mauro Cirano, Janini Pereira, Leticia Cotrim da Cunha
Summary: This study analyzed the Brazilian Equatorial Shelf using a high-resolution ocean model and found significant tidal variations in the area. Several hypothetical barrages were proposed with higher annual power generation than existing barrages. The study also evaluated the installation effort of these barrages.
Article
Green & Sustainable Science & Technology
Francesco Superchi, Nathan Giovannini, Antonis Moustakis, George Pechlivanoglou, Alessandro Bianchini
Summary: This study focuses on the optimization of a hybrid power station on the Tilos island in Greece, aiming to increase energy export and revenue by optimizing energy fluxes. Different scenarios are proposed to examine the impact of different agreements with the grid operator on the optimal solution.
Article
Green & Sustainable Science & Technology
Peimaneh Shirazi, Amirmohammad Behzadi, Pouria Ahmadi, Sasan Sadrizadeh
Summary: This research presents two novel energy production/storage/usage systems to reduce energy consumption and environmental effects in buildings. A biomass-fired model and a solar-driven system integrated with photovoltaic thermal (PVT) panels and a heat pump were designed and assessed. The results indicate that the solar-based system has an acceptable energy cost and the PVT-based system with a heat pump is environmentally superior. The biomass-fired system shows excellent efficiency.
Article
Green & Sustainable Science & Technology
Zihao Qi, Yingling Cai, Yunxiang Cui
Summary: This study aims to investigate the operational characteristics of the solar-ground source heat pump system (SGSHPS) in Shanghai under different operation modes. It concludes that tandem operation mode 1 is the optimal mode for winter operation in terms of energy efficiency.
Article
Green & Sustainable Science & Technology
L. Bartolucci, S. Cordiner, A. Di Carlo, A. Gallifuoco, P. Mele, V. Mulone
Summary: Spent coffee grounds are a valuable biogenic waste that can be used as a source of biofuels and valuable chemicals through pyrolysis and solvent extraction processes. The study found that heavy organic bio-oil derived from coffee grounds can be used as a carbon-rich biofuel, while solvent extraction can extract xantines and p-benzoquinone, which are important chemicals for various industries. The results highlight the promising potential of solvent extraction in improving the economic viability of coffee grounds pyrolysis-based biorefineries.
Article
Green & Sustainable Science & Technology
Luiza de Queiroz Correa, Diego Bagnis, Pedro Rabelo Melo Franco, Esly Ferreira da Costa Junior, Andrea Oliveira Souza da Costa
Summary: Building-integrated photovoltaics, especially organic solar technology, are important for reducing greenhouse gas emissions in the building sector. This study analyzed the performance of organic panels laminated in glass in a vertical installation in Latin America. Results showed that glass lamination and vertical orientation preserved the panels' performance and led to higher energy generation in winter.
Article
Green & Sustainable Science & Technology
Zhipei Hu, Shuo Jiang, Zhigao Sun, Jun Li
Summary: This study proposes innovative fin arrangements to enhance the thermal performance of latent heat storage units. Through optimization of fin distribution and prediction of transient melting behaviors, it is found that fin structures significantly influence heat transfer characteristics and melting behaviors.