Article
Mathematics, Applied
K. Chikhaoui, R. Mosquera, Y. Guevel, J. M. Cadou, E. Liberge
Summary: This paper proposes a model order reduction procedure that uses Proper Orthogonal Decomposition (POD) and Grassmann manifold-based Interpolation (GI) to accurately approximate the dynamic behavior of mechanical structures with reduced computational cost. The approach involves building reduced bases using POD in an offline phase and using GI to interpolate subspaces in an online phase. The results demonstrate the efficiency of this approach in terms of accuracy and computing time reduction.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2023)
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
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
Engineering, Mechanical
Jie Liu, Kun Li
Summary: This paper proposes a novel and efficient method utilizing blind source separation and orthogonal matching pursuit to identify time-space coupled distributed dynamic loads. By decomposing the load into spatial and time functions, using methods like regularization and Green's kernel function, the load is represented as concentrated dynamic loads, demonstrating reasonableness and effectiveness through numerical examples.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Thermodynamics
Jiacheng Ma, Donghun Kim, James E. Braun
Summary: This paper presents a computationally efficient and accurate dynamic modeling approach for vapor compression systems using model order reduction techniques. By reformulating the heat exchanger model and applying POD, reduced order models for evaporator and condenser are constructed with system stability and numerical efficiency in mind. Transient simulations conducted under various operating conditions show that the reduced order model can execute faster with negligible prediction errors compared to the high-fidelity finite volume model.
INTERNATIONAL JOURNAL OF REFRIGERATION
(2021)
Article
Engineering, Aerospace
Xianfei Yan, Dongxu Du, Honghao Liu, Kunpeng Xu, Wei Sun
Summary: A graded modeling method is proposed in this paper to model complex blisks with coating-geometric mistuning, blade-substrate multi-mistuning, and coating-material nonlinearity. Numerical analyses demonstrate that the developed method has higher computational efficiency and accuracy compared to other reduced-order models.
Article
Construction & Building Technology
Yukun Xu, Xiaobin Wei, Yanlei Yu, Yunfei Xia, Lingjie Zeng, Guangyu Cao, Jun Gao
Summary: Designing an efficient dynamic protective air supply (DPAS) system is critical for protecting the respiratory health of workers in polluted industrial settings. This study develops an inverse design method for DPAS based on proper orthogonal decomposition (POD) to optimize its parameters and enable adjustments based on personnel locations. The performance of the DPAS is evaluated by analyzing the pollution concentration distribution in an experimental chamber. The results demonstrate the rationality and accuracy of the POD-based inverse design method, contributing to the advancement of ventilation techniques for respiratory protection during worker movement.
SUSTAINABLE CITIES AND SOCIETY
(2023)
Article
Mechanics
Yuan Yuan, Kaiwen Zhou, Wenwu Zhou, Xin Wen, Yingzheng Liu
Summary: A method for flow field prediction based on local PIV measurement with time-delay embedding is developed. The DMD with time-delay embedding improves both spatial and temporal resolution of flow field prediction, showing high accuracy and robustness to noise.
Article
Engineering, Mechanical
Giorgio Gobat, Andrea Opreni, Stefania Fresca, Andrea Manzoni, Attilio Frangi
Summary: In this study, the Proper Orthogonal Decomposition (POD) method is applied to efficiently simulate the nonlinear behavior of Micro-Electro-Mechanical-Systems (MEMS) in various scenarios involving geometric and electrostatic nonlinearities. The POD method reduces the polynomial terms up to cubic order associated with large displacements through exact projection onto a low-dimensional subspace spanned by the Proper Orthogonal Modes (POMs). Electrostatic nonlinearities are modeled using precomputed manifolds based on the amplitudes of the electrically active POMs. The reliability of the assumed linear trial space is extensively tested in challenging applications such as resonators, micromirrors, and arches with internal resonances. Comparisons are made between the periodic orbits computed with POD and the invariant manifold approximated with Direct Normal Form approaches, highlighting the reliability and remarkable predictive capabilities of the technique, particularly in terms of estimating the frequency response function of selected output quantities of interest.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Mathematics, Applied
Xiaodong Li, Steven Hulshoff, Stefan Hickel
Summary: Proper Orthogonal Decomposition (POD) is crucial for analyzing complex nonlinear systems governed by partial differential equations (PDEs). Traditional POD methods face challenges in storing high-dimensional solutions, leading to the development of incremental Singular Value Decomposition (SVD). To reduce the total computing cost, the proposed enhanced algorithm for incremental SVD incorporates POD mode truncation. The effectiveness of this algorithm is demonstrated through numerical experiments.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2022)
Article
Engineering, Multidisciplinary
Stefania Fresca, Andrea Manzoni
Summary: DL-ROMs are proposed to overcome limitations of conventional ROMs, but require expensive training. The proposed method combines POD and multi-fidelity pretraining to avoid the costly training stage of DL-ROMs.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Mechanics
Jie Hou, Alfa Heryudono, Wenzhen Huang, Jun Li
Summary: This article presents the use of the proper generalized decomposition (PGD) method for parametric solutions of full stress fields in heterogeneous materials. PGD enables accurate prediction of the full stress fields including all localized stress concentration patterns.
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
Engineering, Mechanical
Haijun Peng, Ningning Song, Ziyun Kan
Summary: This paper introduces a novel model order reduction strategy for simulating flexible multibody systems based on the idea of data-driven models, known as the symplectic model order reduction. By obtaining snapshot matrices and converting them to symplectic matrices using cotangent lift, as well as conducting a systematic study on model order reduction at both system and component levels, the proposed method is validated to have better numerical accuracy and computational efficiency compared to classic POD-based models.
NONLINEAR DYNAMICS
(2022)
Article
Thermodynamics
Weixuan Li, Dan Zhao, Linqing Zhang, Xiong Chen
Summary: This study provides detailed analyses of the SFRJ flow field in the presence of self-excited combustion instability using POD and DMD approaches, revealing the flow characteristics and energy distribution among the unstable modes.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2022)
Article
Energy & Fuels
Qiang Zhou, Xinwei Zhao, Lin Pei, Hongkun Li
Summary: This study investigated the pressure pulsation and modal properties of a scaled RCP impeller using experimental and numerical methods. It was found that pressure pulsation on the impeller blade is mainly dominated by the impeller rotating frequency, the vane passing frequency, and the double blade-passing frequency. The impeller's natural frequencies were reduced by 31.63% to 37.77% due to the added mass effect of the fluid, but there is no risk of resonance in the impeller.
ENERGY SCIENCE & ENGINEERING
(2021)
Article
Thermodynamics
Xinwei Zhao, Hongkun Li, Shuhua Yang, Zhenfang Fan, Yang Wang
Summary: This study enhances the understanding of the IGV preswirl effect and blade response through experimental data, finding that blade response increases with larger positive regulation and significant vibration can occur under specific operating conditions. This increase is attributed to changes in aerodynamic loading due to enhanced distortion of the inlet flow.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART A-JOURNAL OF POWER AND ENERGY
(2021)
Article
Engineering, Electrical & Electronic
Jiannan Dong, Hongkun Li, Zhenfang Fan, Xinwei Zhao
Summary: In this article, the reconstruction of time-frequency characteristics of sparse multi-band signals using the discrete multi-coset sampling (DMCS) model was addressed. The proposed method involves the utilization of a multi-coset sliding window (MCSW) for locally windowing the discrete multi-coset sampling sequence, leading to optimal time-frequency reconstruction of the original signal. Numerical simulations demonstrated the feasibility of the method, which is significant for sub-Nyquist sampling technique research and development.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2021)
Article
Acoustics
Zhenfang Fan, Hongkun Li, Jiannan Dong, Xinwei Zhao, Daitong Wei, Qiang Zhou
Summary: This study demonstrates that blade vibration difference can estimate blade vibration and establishes a two-probe blade vibration measurement system. A method for parameter identification of blade vibration based on blade vibration difference is proposed, verifying that blade vibration difference can be measured with high accuracy by the BTT system, with consistent frequency results.
JOURNAL OF SOUND AND VIBRATION
(2021)
Article
Engineering, Mechanical
Hongkun Li, Xinwei Zhao, Qiang Zhou, Shuhua Yang, Xiaowen Zhang
Summary: Understanding the fluid-structure interaction phenomena in centrifugal compressors is crucial for impeller structural integrity design. In this study, a single-stage centrifugal compressor representative of industrial architecture was investigated experimentally to enhance the understanding of blade vibration in a realistic flow environment. The findings reveal that the impeller first bending mode exhibits traveling wave response characteristic only within a specific frequency band. Moreover, unexpected nonsynchronous vibrations were observed when operating near the flow instability boundary. These results contribute to a deep understanding of aeroelastic phenomena in industrial centrifugal compressors and have implications for aeroelastic design and numerical predictions near stall.
JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME
(2022)
Article
Engineering, Mechanical
Zhenfang Fan, Hongkun Li, Jiannan Dong, Xinwei Zhao
Summary: Blade Tip Timing technology is effective for blade vibration measurement in turbomachinery, but faces challenges. This study investigates errors in blade vibration measurement caused by speed fluctuation, proposing an improved MPR method. Through numerical simulation and experiments, the feasibility and reliability of MPR method are verified and successfully applied to large compressors.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Acoustics
Daitong Wei, Hongkun Li, Yugang Chen, Hongwei Cao, Zhenfang Fan, Yuzhi Li
Summary: In this paper, a blade tip timing (BTT) data simulator based on reduced order model (ROM) is developed to improve the calculation efficiency of high fidelity finite element model (FEM) and solve the problem of high BTT test cost. The simulator considers the influence of rotation effect, mistuned, and speed fluctuation, providing a new data generation method for effectively verifying the effectiveness of vibration parameter identification algorithm.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Acoustics
Hongkun Li, Jiannan Dong, Zhenfang Fan, Daitong Wei, Yugang Chen
Summary: In this paper, a novel multiscale cyclic-reverse optimized arrangement (MC-ROA) method based on the random arrangement of tip-timing probes is proposed to achieve frequency identification of undersampled signals in synchronous resonance. The method builds a sparse model for frequency recovery and utilizes the subspace pursuit (SP) algorithm of compressive sensing (CS) for frequency recovery. By adjusting the number of probes and selecting data probes cyclically under random arrangement, multiple sets of solutions are obtained. The target frequency weights are used to determine the optimal recovery frequency, overcoming the limitations of the restricted isometry property (RIP) of the parameterized compression matrix. BTT experiments are conducted to verify the effectiveness of the proposed method.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Engineering, Multidisciplinary
Hongkun Li, Zhenfang Fan, Jiannan Dong, Yugang Chen, Hongwei Cao, Daitong Wei
Summary: Synchronous vibration parameter identification is crucial for monitoring and managing the status of rotating blades. The traditional two-parameter plot method has limitations in accuracy due to measurement errors and restrictions in recognizing engine order. This study presents an improved method called blade vibration difference-based two-parameter plot, which utilizes arrival and departure times of blades to establish differences in vibration. The reliability and feasibility of this method are verified through theoretical deduction, simulation analysis, and experimental research. The engine order obtained by this method matches well with strain results and the identified amplitude deviates from existing methods by only 6.01 percent.
Article
Engineering, Mechanical
Jiannan Dong, Hongkun Li, Zhenfang Fan, Xinwei Zhao, Daitong Wei, Yugang Chen
Summary: This study explores the characteristics of BTT signals under blade synchronous resonance and proposes a subspace pursuit algorithm suitable for this feature. Experimental results demonstrate that the algorithm can recover the synchronous resonance frequency of blades with a higher probability, providing a new approach for the development of BTT technology.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Engineering, Mechanical
Zhenfang Fan, Hongkun Li, Jiannan Dong, Daitong Wei, Hongwei Cao, Yugang Chen
Summary: Blade tip timing (BTT) is an effective technique for vibration monitoring of rotating blades. This paper proposed a mistuning identification method based on blade natural frequency deviation, which achieves quantitative evaluation and online model update of mistuned blisk. Additionally, an improved dynamic strain prediction method for non-contact measurement of blade strain was proposed. Improved mistuning identification and dynamic strain prediction methods with the application of BTT technology significantly promote the application of BTT technology in blade vibration monitoring.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Engineering, Mechanical
Daitong Wei, Yugang Chen, Hongkun Li, Xiaowen Zhang
Summary: A dynamic response field reconstruction method based on blade tip timing (BTT) data is proposed to evaluate the global vibration state of rotating bladed disks online. The method includes a blade tip vibration decoupling method and a blade tip vibration phase shift method, and it realizes the reconstruction of dynamic displacement field and dynamic strain field. The proposed method is verified and the reconstruction errors are analyzed using simulation data and experimental data.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Engineering, Electrical & Electronic
Zhenfang Fan, Hongkun Li, Jiannan Dong, Xinwei Zhao, Hongwei Cao
Summary: This paper introduces the importance of Blade Tip Timing (BIT) technology in estimating blade vibration and diagnosing faults, proposes the SSLF method to overcome the limitations of the OPR method, and verifies the effectiveness of the SSLF method through theoretical analysis and experimental investigations.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2021)
Article
Engineering, Aerospace
Andre F. P. Ribeiro, Carlos Ferreira, Damiano Casalino
Summary: This study compares a filament-based free wake panel method to experimental and validated numerical data in order to simulate propeller slipstreams and their interaction with aircraft components. The results show that the free wake panel method is able to successfully capture the slipstream deformation and shearing, making it a useful tool for propeller-wing interaction in preliminary aircraft design.
AEROSPACE SCIENCE AND TECHNOLOGY
(2024)
