On an Averaged Energy-balance Method for the Analysis of Wavy Microchannels
On an Averaged Energy-balance Method for the Analysis of Wavy Microchannels
复制标题
波状微通道分析的平均能量平衡法
DOI：
10.1007/s00231-022-03329-5
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发表时间：
2023
影响因子：
2.2
通讯作者：
Pacheco-Vega, Arturo
中科院分区：
文献类型：
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作者：
Durantes, Roxana;Moon, Justin;Pacheco, J. Rafael;Pacheco-Vega, Arturo
本文对波纹微通道内的对流换热进行了数值模拟，研究了波纹微通道内的强化换热。其目的是提出一种基于设备中的局部和全局能量平衡的方法，而不是通常使用的努塞尔数，作为热分析的替代方法。这项研究是在一个尺寸为0.5 mm×0.5 mm×20 mm的单波微波通道模型上进行的，通道内流动的水暴露在底部47W/cm处的热流中。首先建立了不可压缩层流和共轭换热的控制方程，然后以铜为固体块状材料，在多种操作条件(冷水流量分别为100和150)下，对典型模型进行了有限元求解。根据计算的速度、压力和温度场，基于横截面平均速度和温度的局部和全局能量平衡可以计算相应设备每个部分的热速率。对蛇形和发散-收敛两种不同布局的研究结果表明，这种所谓的平均能量平衡方法比基于Nusselt数的方法具有更高的精度，因为不需要传递系数或特征温度。
This study presents numerical simulations of the convective heat transfer on wavy microchannels to investigate heat transfer enhancement in these systems. The objective is to propose a methodology based on local and global energy balances in the device, instead of the commonly used Nusselt number, as an alternative for the thermal analysis. This investigation is carried out on a single-wave microchannel model of size 0.5 mm by 0.5 mm by 20 mm length, with water flowing inside the channel, exposed to a heat influx of 47 W/cmat the bottom. The governing equations for an incompressible laminar flow and conjugate heat transfer are first built, and then solved, for representative models, with copper as the solid-block material under a number of operating conditions (cold-water flowrates of, 100, and 150), by the finite element technique. From computed velocity, pressure and temperature fields, local and global energy balances based on cross-section-averaged velocities and temperatures enable calculating the heat rate at each section of the corresponding device. Results from this study for two different designs, namely, serpentine and divergent-convergent layouts, show that this so-called averaged energy-balance methodology enables higher accuracy than that based on Nusselt numbers since neither transfer coefficients nor characteristic temperatures are needed.