An experimental analysis is made to measure the heat transfer, friction factor, thermal performance and effectiveness of Copper/water nanofluids flow in a double pipe U-bend heat exchanger. The Cu nanoparticles are synthesized using chemical reduction method and stable nanofluids are prepared by mixing them in distilled water. The experiments are conducted in the Reynolds number range from 3000 to 30000 and in the volume concentrations of 0.1% and 0.3%. There is an increase of Nusselt number with the increase in particle volume concentrations. The increase of Nusselt number is of the order of 21.73% at particle volume concentration of 0.3% at a Reynolds number of 30000. With the addition of Cu nanoparticles to the distilled water obviously the friction factor penalty is there, this penalty is of the order of 1.141-times. The number of transfer units and effectiveness are directly proportional to the Reynolds number and volume concentrations. With the increase of volume concentrations and Reynolds number, the number of transfer units and effectiveness are increased. The experimental data is fitted based on the least-square method to obtain useful correlations.

中文翻译：

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U型弯双管换热器中铜纳米流体流动的有效性和热性能分析

进行了实验分析，以测量双管U型弯管换热器中铜/水纳米流体流动的传热，摩擦系数，热性能和有效性。使用化学还原法合成铜纳米颗粒，并通过将它们混合在蒸馏水中制备稳定的纳米流体。实验在雷诺数为3000至30000的范围内进行，体积浓度为0.1％和0.3％。随着颗粒体积浓度的增加，努塞尔数增加。当雷诺数为30000时，当颗粒体积浓度为0.3％时，努塞尔数的增加约为21.73％。向蒸馏水中添加铜纳米颗粒显然存在摩擦系数的损失，该损失的程度约为的1.141倍 转移单位的数量和有效性与雷诺数和体积浓度成正比。随着体积浓度和雷诺数的增加，转移单位的数目和有效性增加。基于最小二乘法拟合实验数据以获得有用的相关性。