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Proper orthogonal decomposition (POD) is often employed in developing reduced-order models (ROM) in fluid flows for design, control, and optimization. Contrary to the usual practice where velocity field is the focus, we apply the POD…

Computational Engineering, Finance, and Science · Computer Science 2020-10-27 Muhammad Sufyan , Hamayun Farooq , Imran Akhtar , Zafar Bangash

Hall thrusters are susceptible to large-amplitude plasma oscillations that impact thruster performance and lifetime and are also difficult to model. High-speed cameras are a popular tool to study these dynamics due to their spatial…

Plasma Physics · Physics 2022-05-31 J. W. Brooks , M. S. McDonald , A. A. Kaptanoglu

Understanding flow structures in urban areas is widely recognized as a challenging concern due to its effect on urban development, air quality, and pollutant dispersion. In this study, state-of-the-art data-driven methods for modal analysis…

Fluid dynamics systems driven by dominant, nearly periodic large-scale dynamics are common across wakes, jets, rotating machinery, and high-speed flows. Traditional decomposition techniques such as proper orthogonal decomposition and…

Fluid Dynamics · Physics 2024-05-02 Akhileshwar Borra , Zoey Flynn , Andres Goza , Theresa Saxton-Fox

Most of the studies on pressure fluctuations in wall-bounded turbulent flows aim at obtaining statistics as power spectra and scaling laws, especially at the walls. In the present study we study energetic coherent pressure structures of…

Fluid Dynamics · Physics 2024-07-23 F. R. Amaral , A. V. G. Cavalieri

Data-driven decompositions of Particle Image Velocimetry (PIV) measurements are widely used for a variety of purposes, including the detection of coherent features (e.g., vortical structures), filtering operations (e.g., outlier removal or…

Fluid Dynamics · Physics 2020-08-26 Miguel A Mendez , David Hess , Bo B Watz , Jean-Marie Buchlin

Transport-dominated phenomena provide a challenge for common mode-based model reduction approaches. We present a model reduction method, which is suited for these kind of systems. It extends the proper orthogonal decomposition (POD) by…

Numerical Analysis · Mathematics 2018-02-20 Julius Reiss , Philipp Schulze , Jörn Sesterhenn , Volker Mehrmann

The spatio-temporal dynamics of the solar photosphere is studied by performing a Proper Orthogonal Decomposition (POD) of line of sight velocity fields computed from high resolution data coming from the MDI/SOHO instrument. Using this…

Astrophysics · Physics 2009-11-13 A. Vecchio , V. Carbone , F. Lepreti , L. Primavera , L. Sorriso-Valvo , P. Veltri , G. Alfonsi , Th. Straus

We study reduced-order models of three-dimensional perturbations in linearized channel flow using balanced proper orthogonal decomposition (BPOD). The models are obtained from three-dimensional simulations in physical space as opposed to…

Optimization and Control · Mathematics 2009-11-13 Miloš Ilak , Clarence W. Rowley

This paper concerns the study of direct numerical simulation (DNS) data of a wavepacket in laminar turbulent transition in a Blasius boundary layer. The decomposition of this wavepacket into a set of "modes" (a basis that spans an…

Fluid Dynamics · Physics 2017-10-03 Kean Lee Kang , K. S. Yeo

The dynamics of coherent structures present in real-world environmental data is analyzed. The method developed in this Paper combines the power of the Proper Orthogonal Decomposition (POD) technique to identify these coherent structures in…

Chaotic Dynamics · Physics 2009-10-31 Cristobal Lopez , Emilio Hernandez-Garcia

We present a formalism for dissipation-optimized decomposition of the strain rate tensor (SRT) of turbulent flow data using Proper Orthogonal Decomposition (POD). The formalism includes a novel inverse spectral SRT operator allowing the…

Statistical tools are crucial for studying and modeling turbulent flows, where chaotic velocity fluctuations span a wide range of spatial and temporal scales. Advances in image velocimetry, especially in tracking-based methods, now allow…

Fluid Dynamics · Physics 2025-02-19 Miguel A. Mendez , Manuel Ratz , Damien Rigutto

In particle-laden turbulence, the Fourier Lagrangian spectrum of each phase is regularly computed, and analytically derived response functions relate the Lagrangian spectrum of the fluid- and the particle phase. However, due to the periodic…

Modal decomposition methods are important for characterizing the low-dimensional dynamics of complex systems, including turbulent flows. Different methods have varying data requirements and produce modes with different properties. Spectral…

Fluid Dynamics · Physics 2025-08-28 Caroline Cardinale , Steven L. Brunton , Tim Colonius

Modal decomposition techniques are showing a fast growth in popularity for their good properties as data-driven tools. There are several modal decomposition techniques, yet Proper Orthogonal Decomposition (POD) and Dynamic Mode…

Energy transfer across scales is fundamental in fluid dynamics, linking large-scale flow motions to small-scale turbulent structures in engineering and natural environments. Triadic interactions among three wave components form complex…

Fluid Dynamics · Physics 2024-11-21 Brandon Yeung , Tianyi Chu , Oliver T. Schmidt

In this paper, we propose a computationally efficient iterative algorithm for proper orthogonal decomposition (POD) using random sampling based techniques. In this algorithm, additional rows and columns are sampled and a merging technique…

Numerical Analysis · Mathematics 2020-11-23 Charumathi V , M. Ramakrishna , Vinita Vasudevan

In this paper, we propose a computationally efficient iterative algorithm for proper orthogonal decomposition (POD) using random sampling based techniques. In this algorithm, additional rows and columns are sampled and a merging technique…

Numerical Analysis · Computer Science 2021-07-07 V. Charumathi , M. Ramakrishna , Vinita Vasudevan

We performed a comparative study of extraction of large-scale flow structures in Rayleigh B\'enard convection using proper orthogonal decomposition (POD) and {\em Fourier analysis}. We show that the free-slip basis functions capture the…

Fluid Dynamics · Physics 2017-05-30 Supriyo Paul , Mahendra K. Verma