In this study, the heat transfer and flow characteristics of TiO₂-H₂O nanofluids with TiO₂ mass fractions of 0.0, 0.1, 0.3, and 0.5 wt.% in corrugated and smooth double-pipe heat exchangers were compared using numerical simulations. The results demonstrated that TiO₂-H₂O nanofluids effectively enhanced the heat transfer compared to deionized water, and that the heat exchange capacity gradually increased with the TiO₂ mass fraction. The corrugated pipe heat exchanger disturbed the fluid flow on both the shell side and pipe side, breaking the boundary layer and creating vortices in the corrugated zone. This provided a higher heat transfer capability than the smooth double-pipe heat exchanger, but also increased the fluid flow resistance in the pipe. In general, the use of nanofluids and corrugated pipes was found to significantly improve the heat transfer efficiency of the double-pipe heat exchanger.

中文翻译：

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波纹双管换热器中纳米流体强制对流的数值模拟

_{在这项研究中，使用数值模拟比较了 TiO 2}质量分数为 0.0、0.1、0.3 和 0.5 wt.%的 TiO ₂ -H ₂ O 纳米流体在波纹和光滑双管换热器中的传热和流动特性。结果表明，与去离子水相比，TiO ₂ -H ₂ O纳米流体有效地增强了传热，并且随着TiO _{2的加入，热交换能力逐渐增加。}质量分数。波纹管换热器扰乱了壳程和管程的流体流动，破坏了边界层并在波纹区产生了涡流。这提供了比光滑双管换热器更高的传热能力，但也增加了管道中的流体流动阻力。总的来说，发现使用纳米流体和波纹管可以显着提高双管换热器的传热效率。