In view of the fact that the power of the nano technology and its many potential application in thermal science , the thesis mainly discussed the potential application of the nano technology in micro scale heat transfer , the stability of the nano particle suspension . experimental facility was designed and built up to study flow and heat transfer performance of cuo nano particle suspension and water in mini tubes 鉴于纳米技术表现出的强大生命力和在热科学领域中潜在的广阔应用前景，本文探讨了纳米悬浮液的稳定性，设计和建立了实验系统，实验研究了细圆管内氧化铜纳米颗粒悬浮液流动及换热特性，包括流动阻力特性，流动的转捩和换热特性。
All of the results indicated the turbulent boundary layer had been turned into the laminar layer . the skin friction coefficient drops rapidly . this result not only proved the phenomenon of reverse transition had occurred , but also showed that this condition was drag - reducing condition 实验结果表明板面附近的流动已由湍流流动转变为层流流动，同时平板表面的摩擦系数较没有温度梯度时有大幅度下降，不仅证明了边界层逆转捩现象的存在，也说明了这种条件起到了减阻的效果。
An experimental investigation on the transition in the boundary layer of horizontal plane with and without single two - dimensional roughness elements has been carried out in the wind tunnel . the distribution in normal and stream - wise directions of intensity of t - s wave excited by vibrating beam was measured in every condition . neutral curves were obtained by measuring the growth of the t - s wave at the normal critical location along the stream - wise direction 在风洞中对水平光滑平板以及加有粗糙元平板的边界层转捩进行了测量与研究，比较了不同情况下平板边界层内由振动梁激励生成的t - s波沿流向和法向强度的分布规律，得到了相应的振型增长曲线以及中性曲线。
Based on these parameters , the present work studies the transition of pipe flow with the different amplitude of psb disturbance . the present work simulates the whole time - space process of the transition from laminar to turbulence and secondary transition phenomenon in pipe flow for the first time . the main structure in pipe flow transition is hair - pin vortex ; the evolution of hair - pin vortex is related with the transition of pipe flow 在这一组参数下，本文研究了不同扰动幅值的psb扰动作用下圆管流动的转捩过程，首次给出圆管流动从层流转捩到湍流的时空演化全过程，发现了圆管流动的二次转捩现象，并进一步揭示了发卡涡是圆管流动转捩中的主要结构，流动的转捩过程与发卡涡的演化直接相关。
Abstract : in this paper , a principle and method of the speed pulse waveform sampling are introduced . its object is to study an effect of the turning factor on torbulence . test is done in the aerofoil fengwen . on design of the user interface , application of the timer and displaying way of a pape and continuity are specifically discussed . expermental results and analysis is showed at the last 文摘:以翼型风洞为对象，着重介绍了变湍流度对翼型转捩因子影响的速度脉动波形采集的原理和方法，重点对波形采集系统用户界面的设计、定时器的应用、分页显示和连续显示等技术进行了具体介绍，并给出了实验结果及分析。
