纳米颗粒形状对螺旋管强化传热的影响

采用欧拉-拉格朗日两相法研究了螺旋管内不同形状纳米流体的传热性能。分析了纳米颗粒形状对螺旋管内传热强度、压降、热力性能的影响。研究结果显示:不同颗粒形状对螺旋管内纳米流体传热强度和压降的影响趋势一致,即传热强度和压降由高到低的顺序为血小板形、圆柱形、刀片形、球形、砖形;在颗粒球形度一定时,粒径越小,传热强度越大,压降也越大;血小板形纳米流体的热力性能优于其他颗粒形状,其在Re为1 750时热力性能系数达到最大值1.11。

Effect of Nanoparticle Shapes on Heat Transfer Enhancement in Helical Coiled Tube

The heat transfer performance of nanofluids with different shapes in helical coiled tube is studied in Eulerian-Lagrangian two-phase method.The effect of different particle shapes on the intensity of heat transfer,pressure drop,thermal performance are analyzed in helical coiled tube.The results show that the effect of particle shape on nanofluidsheat transfer intensity and pressure drop has the same change trend.The order of decreasing on the heat transfer intensity and pressure drop is as follows:Platelet,Cylinder,Blade,Sphere,Brick.When the particle shape remains unchanged,the smaller the particle size,the greater the heat transfer intensity,and the greater the pressure drop.The thermal performance of the platelet nanofluids is better than other particle shapes,and the maximum value of the thermal performance factor is 1.11 at Re=1 750.