caa a22 4500 606198423 CHVBK 20210128100934.0 cr unu---uuuuu 210128e20150801xx s 000 0 eng 10.1007/s00348-015-2015-6 doi (NATIONALLICENCE)springer-10.1007/s00348-015-2015-6 On the accuracy of dynamic mode decomposition in estimating instability of wave packet [Elektronische Daten] [Chong Pan, Dong Xue, Jinjun Wang] Lots of unstable flows in both nature and engineering pose multi-scale perturbations with infinitesimal initial amplitude, which compete and interact with each other during their unstable evolution. Dynamic mode decomposition (DMD) analysis can be used to extract these components' temporal/spatial growth rate. Therefore, it is necessary to evaluate the accuracy performance and confidence limit of DMD algorithm in the circumstance of multi-scale instability wave packet. In the present study, we use a linear combination of a sinusoidal unstable wave and its high-order harmonics as a prototype, based on which an error analysis of DMD algorithm is taken. In first, different numerical algorithms of DMD analysis are compared in terms of both accuracy and efficiency. The accuracy evaluation of the classical DMD algorithm in a large parameter domain is followed. It is found that the superimposition of finer structures with less energy dominance might damage the estimation accuracy of the primary structures' growth rate. Strong evidences suggest that even in a linear circumstance, resolving the dynamics of small-scale structures is comparably more difficult than that of the primary structures, i.e., DMD algorithm has a preference for structures with energetic dominance. Finally, the recommended thresholds for the sampling/discretizing parameters are summarized for practical usage. Springer-Verlag Berlin Heidelberg, 2015 Pan Chong Key Laboratory of Fluid Mechanics, Ministry of Education, Beijing University of Aeronautics and Astronautics, 100191, Beijing, China aut Xue Dong Key Laboratory of Fluid Mechanics, Ministry of Education, Beijing University of Aeronautics and Astronautics, 100191, Beijing, China aut Wang Jinjun Key Laboratory of Fluid Mechanics, Ministry of Education, Beijing University of Aeronautics and Astronautics, 100191, Beijing, China aut Experiments in Fluids Springer Berlin Heidelberg 56/8(2015-08-01), 1-15 0723-4864 56:8<1 2015 56 348 https://doi.org/10.1007/s00348-015-2015-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00348-015-2015-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Pan Chong Key Laboratory of Fluid Mechanics, Ministry of Education, Beijing University of Aeronautics and Astronautics, 100191, Beijing, China aut NATIONALLICENCE 700 1- Xue Dong Key Laboratory of Fluid Mechanics, Ministry of Education, Beijing University of Aeronautics and Astronautics, 100191, Beijing, China aut NATIONALLICENCE 700 1- Wang Jinjun Key Laboratory of Fluid Mechanics, Ministry of Education, Beijing University of Aeronautics and Astronautics, 100191, Beijing, China aut NATIONALLICENCE 773 0- Experiments in Fluids Springer Berlin Heidelberg 56/8(2015-08-01), 1-15 0723-4864 56:8<1 2015 56 348