Home // International Journal On Advances in Systems and Measurements, volume 9, numbers 1 and 2, 2016 // View article

Near-wall Thermometry Using Brownian Motion of PIV Particle Tracers

Authors:
Kanjirakat Anoop
Reza Sadr

Keywords: Evanescent wave; Near-wall thermometry; nano-PIV; PIV.

Abstract:
The present work reports an application of near-wall (on the order of 100 nm) thermometry utilizing Brownian motion of nano-particle image velocimetry (nPIV) tracer particles within a solid-fluid interface. Initially, a Monte Carlo simulation of Brownian particle movement in the evanescent wave region in the fluid-wall interface was employed to optimize the relevant measurement parameters. The results of the numerical simulation showed that the ratio of peak-width to peak-height of the nPIV correlation function could be successfully used as a temperature measurement index in the flow. Furthermore, the percentages of the particles remaining in the visible depth of the evanescent wave region may be considered as another thermometric parameter. Experimental studies using an objective-based evanescent wave technique were conducted to verify the results of the numerical simulations and to establish the experimental uncertainty of the temperature measurement. The experimental results verify the feasibility of temperature measurement within ±2.5°C accuracy bond and an out-of-plane resolution of O (100 nm) within the wall region. Variations of the evanescent wave thickness, i.e., out-of-plane resolution of thermometry, did not affect the sensitivity of the temperature measurement. However, the temperature range measured using the objective-based total internal reflection technique was limited due to changes in the optical characteristics of the imaging setup at higher temperatures.

Pages: 38 to 47

Copyright: Copyright (c) to authors, 2016. Used with permission.

Publication date: June 30, 2016

Published in: journal

ISSN: 1942-261x