This paper characterizes the thermal-hydraulic behavior of carbon dioxide near the critical point in rectangular microchannels with uniform heating limited to a single wall of the flow channel. Experiments were conducted in a horizontal, bottom heated channel with a hydraulic diameter of 923 µm and an aspect ratio ($AR=\frac{W_{ch}}{H_{ch}}$) of 3.33. Experimental variables included the mass flux ($430\le \mathit{G}\le 800$ kg m${}^{-2}$ s${}^{-1}$), heat flux ($5.7\le {\mathit{q}}^{{}^{″}}\le 14.12$ W cm${}^{-2}$), inlet temperatures ($31\le T_{in}\le 32.9$ ${}^{\circ }$C), and a reduced pressure ($P_R$) of 1.04. To limit the heating to a single wall of the flow channel, a novel test section was designed and built using Inconel-718, Torlon 4203, and stainless steel. Infrared thermography was used to obtain local heat transfer data. Existing supercritical heat transfer correlations, developed for uniform wall heating conditions, did not accurately predict the heat transfer for single wall heating boundary conditions.

本文描述了矩形微通道中二氧化碳在临界点附近的热工水力行为，均匀加热仅限于流动通道的单壁。实验在水力直径为 923 µm 和纵横比（$\mathrm{一种}\mathrm{电阻}=\frac{{宽}_{CH}}{H_{CH}}$) 的 3.33。实验变量包括质量通量（$430\le \mathit{G}\le 800$ 公斤米${}^{-2}$ 秒${}^{-1}$), 热通量 ($5.7\le {\mathit{q}}^{{}^{”}}\le 14.12$ 厘米${}^{-2}$), 入口温度 ($31\le {吨}_{\mathrm{一世}n}\le 32.9$ ${}^{\circ }$C) 和减压 (${磷}_{\mathrm{电阻}}$) 的 1.04。为了将加热限制在流道的单壁上，使用 Inconel-718、Torlon 4203 和不锈钢设计并建造了一个新的测试部分。红外热成像用于获得局部传热数据。现有的超临界传热相关性是为均匀壁加热条件开发的，不能准确预测单壁加热边界条件的传热。