自润湿液体过冷核态沸腾射液流现象分析

对比去离子水和应用具有自润湿特性的正丁醇水溶液,进行Marangoni效应对微加热面汽泡行为影响的研究。通过高速摄像技术观测到了去离子水中的泡顶射液流和正丁醇溶液中的多射液流现象。相应的数值模拟表明,Marangoni效应引起过冷去离子水从过热表面向泡顶流动,而引起正丁醇溶液向相反方向流动,即过冷溶液流向过热表面。多射液流现象持续时间比去离子水的长,还可引起泡底微液层的瞬时紊乱现象。多射液流现象发生时,汽泡附近的温度梯度较大,而速度梯度则接近垂直于加热表面。正丁醇溶液的模拟结果与实验观测一致,表明表面张力及所引起的Marangoni效应对分析不同流体的过冷核态沸腾机理至关重要。     

液体在固体表面上的铺展动力学

Based on assuming that there is the precursor film in the front of the apparent contact line （ACL）, a model was proposed to understand the dynamic wetting process and associated dynamic contact angle. The present model indicated that a new dimensionless characteristic parameter, 2, attects the dynamic wetting process and associated dynamic contact angle as well. However, the previous model suggested that the dynamic contact angle is dependent＇on the capillary number and static contact angle only. An experimental investigation was conducted to measure the dynamic wetting behavior of silicon oil moving over glass, aluminum and stainless steel surfaces. It concluded that when the value of 2 was selected as 0.07, 0.16 and 0.35 for glass, aluminum and stainless steel, respectively, the experimental results were in good accordance with the prediction of the model. Furthermore, the comparison of the model with Strom＇s experimental data showed that 2 is independent on the species of liquids. Apparently, 2 should be interpreted as the effect of the solid surface properties on the dynamic wetting process.Meanwhile, it is found in the present experiment that the Hoffman-Voinov-Tanner law, which is valid at very low capillary number （Ca 〈〈 1 or 80〈 10°） recommend by Cazabat, still holds for higher contact angles, even up to 70°-80°. This is explained by （he present model very well.     

薄液膜层稳定性分析

本文通过直接对简化的Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程进行摄动分析，考虑相应及表面张力梯度，导出了薄液膜层扰动波增长率的表达式，重点报表面张力梯度和相变对稳定性的影响。     

细圆管内氧化铜颗粒悬浮液流动与对流换热的实验研究

实验研究了氧化铜纳米悬浮液在内径为0.68mm不锈钢细圆管内迫流动和对流换热。氧化铜纳米颗粒悬浮液的质量分数W为0.02-0.06，分别去离子水和水－纳米颗粒悬浮液的流动，传热特性进行了实验测定。实验结果表明：所研究尺度下，层流向湍流过渡早于常规大尺度流动，悬浮液的压降要大于去离子水的；纳米颗粒的质量分数越大，压力降也越大，悬浮液的对流换热系统随颗粒质量分数的增大而增大。     

干法烟气脱硫反应的分布孔隙特性研究

实验测试分析了脱硫反应过程中孔隙结构变化特性，揭示出脱硫反应过程中固体微观孔隙结构变化特点和规律及其对反应转化率的影响，提出了考虑孔隙结构变化的分布孔隙模型，成功描述和分析了脱硫过程动态特性，给出脱硫反应动态和最终转化率，与实验结果较好地相一致。得出了初始孔隙率决定最终反应转化率，孔隙结构分布控制反应过程特性的结论。     

烟气脱硫反应中产物层形成过程特性分析

主要分析了脱硫反应产物层形成过程中的传递反应过程特性。研究发现，脱硫剂颗粒产物层形成过程与蒂勒数密切相关，至产物层形成时转化率仅仅决定于蒂勒数，随蒂勒数的增加而降低，与此阶段持续的时间无关，蒂勒数是描述脱硫反应产物层形成过程中传递反应特性的重要参数，它同时反映了化学反应速度、扩散速度的影响。本文还考察了粒径、孔隙分布方式以及温度对反应过程的影响，证实了随着温度和孔隙率的升高反应转化率相应提高，反应平均孔径在100～300nm之间的孔隙更利于进行脱硫反应，热重分析(TGA)实验结果进一步证实了理论分析的正确性。     

过冷沸腾汽泡顶部射流可视化实验研究

通过商速摄像井配合激光PIV技术，对过冷沸腾中微小汽泡顶部射流进行细致现察，确认过冷沸腾中顶部射流的存在，测量显示其速度场，具体分析讨论此类射流与汽泡生长的联系。     

利用自然冷源的开控式地下贮藏库的合理结构

本文讨论了利用自然冷源的贮果用开挖式地下洞库的合理结构,给出覆盖层厚度不超过两米时,为满足贮藏秋季入库的水果所应该采用的洞库剖面结构,并给出可直接用于工程计算的实用数表分析结果表明,在我国主要苹果产区,即使是平原地区也可以采用地下贮藏库的方式依靠自然冷源解决产地苹果贮存问题。     

Bubble formation of liquid boiling in microchannels

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Convective heat transfer for incompressible laminar gas flow in micropassage with constant wall temperature

Theoretical investigations have been performed on the convective heat transfer for incompressible laminar flow of gases through microtube and parallel-plates micropassages with constant wall temperature. Considering the change in thermal conductivity and viscosity of gas in wall adjacent region from the kinetic theory, mathematical models are built for both of the micropassages. The dimension-less temperature distribution and the corresponding heat transfer characteristics are simulated numerically, and the results discussed briefly.