CuO纳米颗粒悬浮液在小管内的流动和强制对流换热特性

Experimental Research on Forced Convective Flow Drag and Heat Transfer of CuO Nanoparticles Suspensions in a Small Tube

采用去离子水和平均粒径50 nm的CuO纳米粒子经超声波振荡配制H2O-CuO纳米悬浮液,对其在内径1.02 mm不锈钢管内的流动和强制对流换热特性进行研究,并与添加表面扩散剂后的管内强制对流换热和流动特性进行比较.结果表明:与H2O相比,CuO纳米颗粒悬浮液的对流换热特性较强,而流动阻力明显下降;添加表面扩散剂将增大流动阻力,但对换热特性没有影响.纳米粒子在管壁上的沉降是湍流区阻力下降的主要因素.

Experiments were carried out on forced convective drag and heat transfer of nanoparticles suspension in a small steel tube with an inner diameter of 1.02 mm. The base fluid is de-ionized water （He O） and the nanoparticle is oxide copper （CuO） with an average diameter of 50 nm. Comparison of drag and heat transfer characteristics was made between suspensions in which surfactant was not added and nanofluid with surfactant. The experimental results show that the convective heat transfer is enhanced by adding nanoparticles in water. The flow drag of nanopartices suspension in turbulent flow regime is obviously lower than that of pure water. Adding surfactant can increase the flow drag while has no effect on heat transfer. The sedimentation of nanoparticles on the tube wall is the main factor for the flow drag decrease.