Kriging regression of PIV data using a local error estimate

2014-01-01
de Baar, Jouke H. S.
Perçin, Mustafa
Dwight, Richard P.
van Oudheusden, Bas W.
Bijl, Hester
The objective of the method described in this work is to provide an improved reconstruction of an original flow field from experimental velocity data obtained with particle image velocimetry (PIV) technique, by incorporating the local accuracy of the PIV data. The postprocessing method we propose is Kriging regression using a local error estimate (Kriging LE). In Kriging LE, each velocity vector must be accompanied by an estimated measurement uncertainty. The performance of Kriging LE is first tested on synthetically generated PIV images of a two-dimensional flow of four counter-rotating vortices with various seeding and illumination conditions. Kriging LE is found to increase the accuracy of interpolation to a finer grid dramatically at severe reflection and low seeding conditions. We subsequently apply Kriging LE for spatial regression of stereo-PIV data to reconstruct the three-dimensional wake of a flapping-wing micro air vehicle. By qualitatively comparing the large-scale vortical structures, we show that Kriging LE performs better than cubic spline interpolation. By quantitatively comparing the interpolated vorticity to unused measurement data at intermediate planes, we show that Kriging LE outperforms conventional Kriging as well as cubic spline interpolation.
EXPERIMENTS IN FLUIDS

Suggestions

Monte Carlo analysis of the effects of the material and shape uncertainties on radar cross section by the finite difference time domain method
Kazar, Ali Kemal; Kuzuoğlu, Mustafa; Özgün, Özlem; Department of Electrical and Electronics Engineering (2013)
The aim of this research is to analyze the variations in Radar Cross Section (RCS) values of dielectric and conducting objects due to material and shape uncertainties by employing the Finite Difference Time Domain Method and the Monte Carlo approach in electromagnetic scattering problems. MATLAB codes are developed and validated to solve the electromagnetic scattering problem involving two and three dimensional arbitrarily-shaped objects. Basic principles of FDTD and its implementation in MATLAB are describ...
Incompressible flow simulations using least squares spectral element method on adaptively refined triangular grids
Akdağ, Osman; Sert, Cüneyt; Department of Mechanical Engineering (2012)
The main purpose of this study is to develop a flow solver that employs triangular grids to solve two-dimensional, viscous, laminar, steady, incompressible flows. The flow solver is based on Least Squares Spectral Element Method (LSSEM). It has p-type adaptive mesh refinement/coarsening capability and supports p-type nonconforming element interfaces. To validate the developed flow solver several benchmark problems are studied and successful results are obtained. The performances of two different triangular ...
Dynamical modelling of the flow over a flapping wing using proper orthogonal decomposition and system identification techniques
DURMAZ, Oğuz; KARACA, H Deniz; ÖZEN, G Deniz; KASNAKOĞLU, COŞKU; Kurtuluş, Dilek Funda (2013-04-01)
A systematic approach for the dynamical modelling of the unsteady flow over a flapping wing is developed, which is based on instantaneous velocity field data of the flow collected using particle image velocimetry (PIV) and computational fluid dynamics (CFD) simulations. The location and orientation of the airfoil is obtained by image processing and the airfoil is filled with proper velocity data. Proper orthogonal decomposition (POD) is applied to these post-processed images to compute POD modes and time co...
Estimation of Streamflow Using Takagi-Sugeno Fuzzy Rule-Based Model
Akgün, Ömer Burak; Kentel Erdoğan, Elçin (2018-06-01)
In this study, a tool is developed to estimate streamflow at Guvenc Basin, Ankara by using Takagi-Sugeno (TS) Fuzzy Rule-Based (RB) model. The model takes precipitation and runoff at time � as predictor (input) and estimates the runoff at time � + 1. The approach used to generate the TS RB model is based on density based clustering. Each cluster center is used to generate a fuzzy rule that represents the system behaviour. Satisfactory results are obtained especially after including the seasonal behaviour of...
Monte Carlo simulations of Helmholtz scattering from randomly positioned array of scatterers by utilizing coordinate transformations in finite element method
ÖZGÜN, ÖZLEM; Kuzuoğlu, Mustafa (2015-07-01)
Electromagnetic scattering from randomly distributed array of scatterers is numerically analyzed by Monte Carlo simulations by utilizing coordinate transformations in the context of finite element method solution of Helmholtz equation. The major goal in proposed approaches is to place transformation media into computational domain by employing the form invariance property of Maxwell's equations under coordinate transformations, and hence avoiding repeated mesh generation process in multiple realizations of ...
Citation Formats
J. H. S. de Baar, M. Perçin, R. P. Dwight, B. W. van Oudheusden, and H. Bijl, “Kriging regression of PIV data using a local error estimate,” EXPERIMENTS IN FLUIDS, pp. 0–0, 2014, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/40737.