Estimation of the local heat-transfer coefficient in the laminar flow regime in coiled tubes by the Tikhonov regularisation method
Estimation of the local heat-transfer coefficient in the laminar flow regime in coiled tubes by the Tikhonov regularisation method
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DOI：
10.1016/j.ijheatmasstransfer.2014.01.019
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发表时间：
2014-05
影响因子：
5.2
通讯作者：
F. Bozzoli;L. Cattani;S. Rainieri;F. Bazán;L. Borges
中科院分区：
文献类型：
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作者：
F. Bozzoli;L. Cattani;S. Rainieri;F. Bazán;L. Borges
壁面曲率是一种被广泛应用的被动增强对流换热的技术，在高粘性流体的热处理中也被证明是有效的。这些几何形状使壁面处的对流热流密度沿周向坐标分布极不均匀，从而影响了流体热处理的性能。虽然许多作者研究了螺旋管内的强制对流换热问题，但大多数人只给出了沿壁周平均努塞尔数的结果。本文提出了一种估算盘管局部对流壁面热流密度的方法，并对其进行了验证：采用基于Tikhonov正则化方法的求解方法，结合不动点迭代技术，将盘管外壁面温度分布图作为盘管壁面热传导逆问题的输入数据，确定合适的正则化参数。研究的重点是层流流态。
Wall curvature is a widely used technique to passively enhance convective heat transfer that has proven to also be effective in the thermal processing of highly viscous fluids. These geometries produce a highly uneven convective heat-flux distribution at the wall along the circumferential coordinate, thus affecting the performance of the fluid thermal treatment. Although many authors have investigated the forced convective heat transfer in coiled tubes, most of them have presented the results only in terms of the Nusselt number averaged along the wall circumference. A procedure to estimate the local convective wall heat flux in coiled tubes is presented and tested in this paper: the temperature distribution maps on the external coil wall were employed as input data of the inverse heat conduction problem in the wall under a solution approach based on the Tikhonov regularisation method with the support of the fixed-point iteration technique to determine a proper regularisation parameter. The investigation was focused on the laminar flow regime.