Abstract

The mathematical modeling of heat transfer in nanofluids based on the effects of additional particle forces was investigated with computational fluid dynamics simulations of titania-water nanofluid in a heated pipe flow. The additional particle forces analyzed were Brownian force, thermophoresis, Saffman’s lift force and Magnus lift force. The results were validated with an experimental work. The experimental results showed that the enhancements of heat transfer in nanofluids are weaker compared to water owing to the delayed onset of natural convection in the nanofluid flow. The simulation results support the experimental findings and it has been proven that the two-phase Euler–Lagrange simulation models reproduce the experiment better than single-phase simulation. The effects of additional particle forces on the deterioration of heat transfer of nanofluids are negligible. The momentum and heat transfer between base fluid and nanoparticles could be a possible explanation for this phenomenon.

摘要

通过对加热管流中的二氧化钛-水纳米流体进行计算流体动力学模拟，研究了基于附加粒子力影响的纳米流体传热数学模型。分析的附加粒子力是布朗力、热泳、萨夫曼升力和马格努斯升力。结果得到了实验工作的验证。实验结果表明，由于纳米流体流中自然对流的延迟开始，纳米流体中的传热增强比水弱。仿真结果支持了实验结果，并且已经证明两相欧拉-拉格朗日仿真模型比单相仿真更好地再现了实验结果。附加粒子力对纳米流体传热恶化的影响可以忽略不计。基液和纳米颗粒之间的动量和热传递可能是这种现象的一种解释。