A meshless and binless approach to compute statistics in 3D Ensemble PTV

Fuente: arXiv
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Main Authors: Ratz, Manuel, Mendez, Miguel A.
Format: Preprint
Published: 2024
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author Ratz, Manuel
Mendez, Miguel A.
author_facet Ratz, Manuel
Mendez, Miguel A.
contents We propose a method to obtain superresolution of turbulent statistics for three-dimensional ensemble particle tracking velocimetry (EPTV). The method is ''meshless'' because it does not require the definition of a grid for computing derivatives, and it is ''binless'' because it does not require the definition of bins to compute local statistics. The method combines the constrained radial basis function (RBF) formalism introduced Sperotto et al. (Meas Sci Technol, 33:094005, 2022) with a kernel estimate approach for the ensemble averaging of the RBF regressions. The computational cost for the RBF regression is alleviated using the partition of unity method (PUM). Three test cases are considered: (1) a 1D illustrative problem on a Gaussian process, (2) a 3D synthetic test case reproducing a 3D jet-like flow, and (3) an experimental dataset collected for an underwater jet flow at $\text{Re} = 6750$ using a four-camera 3D PTV system. For each test case, the method performances are compared to traditional binning approaches such as Gaussian weighting (Agüí and Jiménez, JFM, 185:447-468, 1987), local polynomial fitting (Agüera et al, Meas Sci Technol, 27:124011, 2016), as well as a binned version of the RBF statistics.
format Preprint
id arxiv_https___arxiv_org_abs_2403_11828
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle A meshless and binless approach to compute statistics in 3D Ensemble PTV
Ratz, Manuel
Mendez, Miguel A.
Fluid Dynamics
We propose a method to obtain superresolution of turbulent statistics for three-dimensional ensemble particle tracking velocimetry (EPTV). The method is ''meshless'' because it does not require the definition of a grid for computing derivatives, and it is ''binless'' because it does not require the definition of bins to compute local statistics. The method combines the constrained radial basis function (RBF) formalism introduced Sperotto et al. (Meas Sci Technol, 33:094005, 2022) with a kernel estimate approach for the ensemble averaging of the RBF regressions. The computational cost for the RBF regression is alleviated using the partition of unity method (PUM). Three test cases are considered: (1) a 1D illustrative problem on a Gaussian process, (2) a 3D synthetic test case reproducing a 3D jet-like flow, and (3) an experimental dataset collected for an underwater jet flow at $\text{Re} = 6750$ using a four-camera 3D PTV system. For each test case, the method performances are compared to traditional binning approaches such as Gaussian weighting (Agüí and Jiménez, JFM, 185:447-468, 1987), local polynomial fitting (Agüera et al, Meas Sci Technol, 27:124011, 2016), as well as a binned version of the RBF statistics.
title A meshless and binless approach to compute statistics in 3D Ensemble PTV
topic Fluid Dynamics
url https://arxiv.org/abs/2403.11828