Use of synthetic flow fields evaluating LSPIV errors

GUILLEN, N.; GARCÍA RODRIGUEZ, CARLOS MARCELO

usa

Conferencia; Hydraulic Measurements & Experimental Methods Conference; 2017

usa

Different digital camera locations, the position of the control points necessary for Large Scale Particle Image Velocity (LSPIV) flow velocity ortho-rectification, and the temporal and spatial video resolutions used for LSPIV flow measurements strongly affect the errors on uncertainty of the measured surface flow velocities. This work presents an attempt to quantify these errors of LSPIV measurements using synthetic flow fields generated using a specific cinema software.First, ten different camera locations were tested: three lateral views, three frontal views, three corner views and a top view. Next, random sampling (Monte Carlo simulation) for the distances between the four control required points were used in order to evaluate the uncertainty of the computed velocity profiles. Then, different temporal and spatial resolutions of the images were evaluated (ranging from 3 to 30 frames per seconds and from 1920x1080 pixels to 960x540 pixels, respectively). Based on these results, some recommendations are presented in order to reduce the surface flow velocity errors in future LSPIV measurements. The results of this work could aid LSPIV practioners by providing tools to define optimum sampling strategies to perform a good characterization of flow fields using LSPIV.