Pressure field estimation from particle image velocimetry data

Günaydınoğlu, Erkan
In this thesis, a methodology is proposed to estimate pressure fields from particle image velocimetry measurements. The methodology uses the velocity fields acquired from the experiments as initial and boundary condition and employs Semi-Implicit Method for Pressure Linked Equations algorithm to solve governing equations. Finite volume method is employed with high order discretization scheme for solution of steady and transient flows. The methodology is validated with theoretical flows and further verified with conventional pressure measurement tools. The sensitivity of the methodology to the velocity field error is also assessed. Method estimates the pressure fields exactly for error free velocity fields. Moreover, method can correct the flow-fields to accurate values even with extremely high experimental uncertainties and errors. The methodology is further employed on a flapping airfoil experiment and capability of pressure estimation is tested for highly vortical flows. The proposed methodology offers a reliable, non-intrusive, global pressure measurements simultaneously with the corresponding velocity fields. Due to the error-correcting nature, it could also be used for quantifying the uncertainties of experimental systems or calibrating numerical tools.


Pressure-velocity coupling algorithm-based pressure reconstruction from PIV for laminar flows
Gunaydinoglu, Erkan; Kurtuluş, Dilek Funda (Springer Science and Business Media LLC, 2020-01-01)
In this study, we propose a method to reconstruct pressure fields from planar particle image velocimetry measurements for laminar flows by employing semi-implicit method for pressure-linked equations algorithm to solve governing equations where measured velocities are inherently used as boundary conditions. The method starts with interpolating the measured velocity field on a staggered computational grid. The continuity equation, in the form of pressure equation for incompressible flows, is solved with this...
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...
Mathematical Modeling of Turbulent Flows of Newtonian Fluids in a Concentric Annulus with Pipe Rotation
SORGUN, MEHMET; Aydın, İsmail; ÖZBAYOĞLU, Evren; SCHUBERT, J J (2012-03-01)
In this study, a mathematical model is proposed to predict flow characteristics of Newtonian fluids inside a concentric horizontal annulus. A numerical solution, including pipe rotation, is developed for calculating frictional head losses in concentric annuli for turbulent flow. Navier-Stokes equations are numerically solved using the finite differences technique to obtain the velocity field. Experiments with water are performed in a concentric annulus with and without pipe rotation. Average fluid velocitie...
Experimental and numerical investigation of pressure swirl atomizers
Sümer, Bülent; Tuncer, İsmail Hakkı; Uzol, Oğuz; Department of Aerospace Engineering (2014)
In this study, unsteady flows inside a pressure swirl atomizer are investigated using experimental and numerical techniques. High Speed Shadowgraphy Technique is used in order to visualize the flow structures inside the atomizer and the resulting spray at high temporal and spatial resolutions. The images of the air core inside the pressure swirl atomizer and the resulting spray formations are captured at four di erent water flow rates. Then, the time variation of the air core diameter at di erent axial loca...
Application of spring analogy mesh deformation technique in airfoil design optimization
Yang, Yosheph; Özgen, Serkan; Department of Aerospace Engineering (2015)
In this thesis, an airfoil design optimization with Computational Fluid Dynamics (CFD) analysis combined with mesh deformation method is elaborated in detail. The mesh deformation technique is conducted based on spring analogy method. Several improvements and modifications are addressed during the implementation of this method. These enhancements are made so that good quality of the mesh can still be maintained and robustness of the solution can be achieved. The capability of mesh deformation is verified by...
Citation Formats
E. Günaydınoğlu, “Pressure field estimation from particle image velocimetry data,” Ph.D. - Doctoral Program, Middle East Technical University, 2018.