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ISSN Online: 2379-1748

ISBN Flash Drive: 978-1-56700-483-0

ISBN Online: 978-1-56700-482-3

4th Thermal and Fluids Engineering Conference
April, 14–17, 2019 , Las Vegas, NV, USA

A Robust and High Resolution Method for Measuring Spatio-Temporal Convective Heat Transfer

Get access (open in a dialog) pages 697-707
DOI: 10.1615/TFEC2019.emt.027352

Abstract

The most common method for measuring spatio-temporal heat transfer is the thin-foil heater approach. In this method, turbulent flow passes over the surface of a thin-foil heating element. Passing current through the foil heater creates uniform volumetric heating. The surface temperature is measured and the convection coefficient is calculated from a surface energy balance and is a function of both space and time. The frequency response and spatial resolution are governed by heat conduction and heat storage within the thin-foil surface and the insulation layer behind the foil. Successful measurements require a sufficiently thin heated layer and insulation with sufficiently low thermal effusivity. The most common approach uses a metallic foil suspended over an air gap. While the air gap provides exceptional insulative properties, flow induced vibrations and heater durability make this approach difficult to implement. A new method is proposed, which uses an innovative combination of materials to improve the durability and robustness when compared with previous methods. Furthermore, the maximum resolvable time and spatial frequencies are increased, which allows for the study of higher Reynolds number flows. These characteristics make the proposed method a promising alternative to measure spatio-temporal convective heat transfer for industrial applications.