SiO_2-水纳米流体在波壁管内流动特性的实验研究

Experimental study on flow behavior of SiO_2-water nanofluids in a wavy-walled tube

实验研究了不同质量分数的SiO2-水纳米流体在波壁管内的流动特性,由于波壁管自身的结构特点,使流体在较小雷诺数下达到湍流状态,可以方便测出流体在层流、过渡流、湍流区的流动特性。研究发现:相同温度条件下,纳米流体的粘度随着质量分数的提高而增大;流动可视化照片显示纳米流体中由于内部纳米粒子的微运动促使流体均匀性更好;沿程阻力测试表明在层流区内摩擦系数随纳米流体质量分数的增加而增大,在过渡流和湍流区内摩擦系数随质量分数增加变化不大。

Experiments were carried out on flow behavior of different mass concentrations SiO2-water nanofluids in a wavy-walled tube,due to the structure characteristics of the wavy-walled tube,the fluid can turn to turbulent area in smaller Reynolds numbers and the flow structure characteristics in the laminar,transitional and turbulent flow region can be easily measured.The result show that the viscosity of the nanofluids increases with the mass concentrations of nanoparticles in the same temperature;the flow visualization shows that the nanofluids have better uniformity due to the micro-movements of the nanoparticles;the result of resistance tests show that the friction factor of nanofluids increases with the mass concentrations of nanoparticles in the laminar flow region and the friction factors of nanofluids have almost no change with the mass concentrations of nanoparticles in the transitional and turbulent flow region.