Thermophoretic deposition of particles in turbulent duct flow is of significant relevance in energy and thermal engineering applications. However, conjugate heat transfer (CHT) was commonly not considered in the previous studies, but may have crucial influences on particle deposition behaviors. Therefore, thermophoretic particle deposition in turbulent duct flow with and without CHT was numerically investigated by using \(\overline {v{\prime ^{_2}}} - f\) turbulence model and discrete particle model (DPM) with a modified discrete random walk method. After grid independence study and numerical verification, several important influencing factors on particle deposition velocity were studied, such as flow Reynolds number, temperature difference between inlet hot air and cool wall, thermal conductivity ratio and width ratio of solid and fluid domain. The thermophoresis greatly increases deposition velocity of small particles but has no influence on large particles. The critical particle relaxation time \(\tau _{\rm{p}}^ + \) for thermophoresis effect is 20, which is the same for all the cases in this study. The corresponding particle diameter is 28 µm. The thermophoretic deposition is enhanced when the flow Reynolds number and temperature difference between air and wall increase. This is because the wall-normal temperature variety is higher for large Reynolds number and temperature difference, which can enhance thermophoretic deposition. However, CHT reduces the thermophoretic deposition by decreasing temperature difference in fluid region. Besides, higher thermal conductivity ratio and width ratio of solid and fluid domain will decrease the thermophoretic deposition, as thermal conduction in solid domain becomes more intense.

中文翻译：

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共轭传热的湍流管道内颗粒热泳沉积的数值研究：影响因素分析

湍流管道中颗粒的热泳沉积在能源和热工程应用中具有重要意义。但是，在先前的研究中通常不考虑共轭传热（CHT），但可能会对颗粒沉积行为产生关键影响。因此，使用\（\ overline {v {\ prime ^ {_ 2}}}-f \）进行了有和没有CHT的湍流管道中的热泳颗粒沉积的数值研究。湍流模型和离散粒子模型（DPM），采用改进的离散随机游动法。经过网格独立性研究和数值验证，研究了影响颗粒沉积速度的几个重要因素，例如流雷诺数，入口热空气与冷壁之间的温差，热导率和固液域宽度比。热泳极大地提高了小颗粒的沉积速度，但对大颗粒没有影响。临界粒子弛豫时间\（\ tau _ {\ rm {p}} ^ + \）对于热泳的效果是20，对于本研究中的所有情况都是相同的。对应的粒径为28μm。当流动雷诺数和空气与壁之间的温差增加时，热泳沉积得到增强。这是因为对于较大的雷诺数和温差，壁面正常温度变化较高，这可以增强热泳沉积。但是，CHT通过减小流体区域的温差来减少热泳沉积。此外，随着固体区中的热传导变得更强烈，较高的固体区和流体区的导热率比和宽度比将减少热泳沉积。