This paper reported numerical simulation investigations on heat transfer performance of ZrO₂-water and Cu-water nanofluids in the tube with concentric double twisted element(CDTE)(Re = 6000-12000). Furthermore, experiments verified that the two-phase flow model method was more suitable for the numerical simulation of nanofluids in the tube with CDTE. The Nusselt numbers with CDTE and nanofluids obviously increased and also showed a positive correlation with the nanofluid concentration. The Nusselt numbers of Cu-water nanofluid were better than ZrO₂-water nanofluid. While the friction factor(f ) of CDTE tube between the nanofluids increased little, the maximum difference was only 3.23%. The heat transfer performance was evaluated by performance evaluation criteria (PEC), cross-section entransy efficiency(ψ_c) and radial-flow(RF) number. The heat transfer performance of Cu-water nanofluids was all superior to ZrO₂-water nanofluids. The PEC values in nanofluids increased with increasing concentration. The maximum PEC value was 1.96 in 1% Cu-water nanofluid. Subsequently, the ψ_c of CDTE tube increased with the increase of cross-section position and nanofluid concentration. The maximum ψ_c was 91.22% in 1% Cu-water nanofluid at Re= 6000. When an appropriate concentration of nanofluids was used and the nanofluid was passed through the CDTE, the RF numbers increased obviously. The maximum RF number was 0.1028 with 0.5% Cu-water nanofluid at Re= 6000.

本文报道了ZrO _2-水和Cu-水纳米流体在同心双扭曲元件（CDTE）（R e = 6000-12000）中的传热性能的数值模拟研究。此外，实验证明，两相流模型方法更适合于采用CDTE的管中纳米流体的数值模拟。CDTE和纳米流体的Nusselt数明显增加，并且与纳米流体浓度呈正相关。铜水纳米流体的Nusselt数优于ZrO _2-水纳米流体。虽然纳米流体之间CDTE管的摩擦因数（f）几乎没有增加，但最大差异仅为3.23 ％。传热性能通过性能评价标准（PEC），横截面火积效率（评价ψ _Ç）和径向流（RF）数。铜水纳米流体的传热性能均优于ZrO _2-水纳米流体。纳米流体中的PEC值随浓度的增加而增加。在1 ％的铜水纳米流体中，最大PEC值为1.96 。随后，ψ _Ç CDTE管的与横截面的位置和纳米流体浓度的增加而增加。最大ψ _Ç是91.22 ％在1 ％的Cu-水纳米流体在ř Ë=6000。当使用适当浓度的纳米流体并使纳米流体通过CDTE时，RF数明显增加。在R e = 6000时使用0.5 ％的铜水纳米流体时，最大RF值为0.1028 。