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arXiv · 2410.07162

Sub-Millimeter-Scale Measurement of Local Convective Heat Transfer Coefficient Exceeding 100 W/(m^2-K) Using an Optical Pump-Probe Method

Tao Chen·Puqing Jiang
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Abstract

Conventional methods for measuring the local convective heat transfer coefficient (h_c) often rely on simplifying assumptions that can compromise accuracy. Pump-probe methods like time-domain thermoreflectance (TDTR) avoid these assumptions but are limited to h_c values larger than 30 kW/(m^2-K) due to modulation frequency constraints. This study introduces an optical-based Square-Pulsed Source (SPS) method, expanding the frequency range from 10 MHz to 1 Hz, enabling measurements of h_c values above 100 W/(m^2-K) with uncertainties under 10%. The efficacy of the SPS method is demonstrated through measurements of local h_c in an impingement heat transfer process with a single round gas jet. The local Nusselt number distribution is compared with existing literature correlations, offering insights into convective heat transfer phenomena. This study presents a novel tool for measuring local intrinsic convective heat transfer coefficients, enhancing the understanding of local convective heat transfer.

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Tao Chen, Puqing Jiang. 2024-10-09. Sub-Millimeter-Scale Measurement of Local Convective Heat Transfer Coefficient Exceeding 100 W/(m^2-K) Using an Optical Pump-Probe Method. https://doi.org/10.1016/j.measurement.2025.117001

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