Temperature Measurement of Fluid Flows by Using a Focusing Schlieren Method.

A Martínez-González,C Carrillo-Delgado,D Moreno-Hernández,J Zamarripa-Ramírez,J Guerrero-Viramontes,M León-Rodríguez

doi:10.3390/s19010012

Abstract

A method for measuring planar temperature fields of fluid flows is proposed. The focusing schlieren technique together with a calibration procedure to fulfill such a purpose is used. The focusing schlieren technique uses an off-axis circular illumination to reduce the depth of focus of the optical system. The calibration procedure is based on the relation of the intensity level of each pixel of a focused schlieren image to the corresponding cutoff grid position measured at the exit focal plane of the schlieren lens. The method is applied to measure planar temperature fields of the hot air issuing from a 10 mm diameter nozzle of a commercial Hot Air Gun Soldering Station Welding. Our tests are carried out at different temperature values and different planes along the radial position of the nozzle of the hot air. The experimental values of temperature measurements are in agree with those measured using a thermocouple.

Highlights

The interest of temperature measurement is important in a wide area of science and the optical full field methods are preferred to fulfill this important task
9, the second and of opticalThe system in this study offer some specific characteristics that limit the range sixth columns are the thermocouple measurements for each case under analysis
The optical system presented in this study offer some specific characteristics that limit the range of temperatures to be measured and the kind of object to be analyzed

Summary

Introduction

The interest of temperature measurement is important in a wide area of science and the optical full field methods are preferred to fulfill this important task. Schlieren technique is one of the most successful optical method used to visualize fluid flows This technique has remarkable advantages like easy to implement, uses conventional light sources, is low cost and is very sensitive [2,3]. This method has been improved to face different types of problems in science and engineering [4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23]. This method has allowed to measure simultaneously temperature and velocity in fluid flows [19,20,21,22]

Objectives

Methods

Findings

Conclusion