基于双组分双流体模型的纳米流体流动沸腾传热特性研究OA

A numerical simulation of the flow boiling process in horizontal circular tubes of nanofluids was conducted using a two-component two-phase flow model.The effects of different Reynolds numbers(Re),nanofluid types and volume fractions on flow and heat transfer were investigated through user-defined function(UDF)programming.The results indicated that the addition of nanoparticles led to an overall decrease in temperature and a reduced amount of steam produced during the boiling process,with the effects becoming more pronounced as the particle volume fraction increased.The study found that Al2O3 nanofluids exhibited a higher heat transfer coefficient,which increased at an accelerating rate with the volume fraction of particles,although the pressure drop also rose corre-spondingly.At high Reynolds numbers,the pressure drop in nanofluids was observed to increase by up to approxi-mately 146％.An entropy production analysis revealed that friction entropy production increased with higher Reyn-olds numbers,while thermal entropy production showed the opposite trend,being more significant at high Reynolds numbers,and further decreasing with the addition of nanoparticle volume fraction.Finally,a comprehensive analy-sis of the heat transfer process using the performance evaluation criterion(PEC)found that the inclusion of parti-cles was beneficial to the heat transfer process,with this enhancement effect becoming more apparent as the particle volume fraction increased.Among the nanofluids studied,Al2O3 displayed the strongest overall heat transfer capa-bilities,followed by TiO2,while Cu nanofluids exhibited the weakest.