Investigation on film cooling characteristics from a row of converging slot-holes on flat plate

Experimental and numerical researches were conducted to investigate the cooling performance of a single row of consoles (converging slot-hole) on a large-scale flat-plate model. The results show that the coolant flow from a row of consoles shows good lateral uniformity of adiabatic effectiveness, with regions of slightly enhanced cooling occurring between the consoles. For the console cooling geometry, the interaction between coolant jet from inclined console and the mainstream flow results in reasonable vo...     

Study on early warning index of spatial deformation for high concrete dam

Owing to the deficiency in early warning for high concrete dam,a formula was established to characterize the deformation behavior of high concrete dam as a whole.The early warning index of spatial deformation was calculated by low probability principle on the basis of the deformation entropy formula proposed.The steps were as follows.Firstly,the probability method was utilized to define the degree of order and degree of chaos for each survey point.Secondly,the weight distribution among the survey points was...     

Dendrite crystal morphology evolution mechanism of β-BaB_2O_4 crystal

Existence of [B3-O6]3- hexagonal ring growth unit in melt solution of β-BaB2O4 crystal was proved by the results of high temperature Raman measurements.A morphology evolution process of β-BaB2O4 crys-tal was observed by a high temperature in-situ observation device.The crystal morphology varied with the supersaturation of growth melt solution.The mechanism of β-BaB2O4 crystal morphology evolution was analyzed through the growth unit model.     

溅射NdFeB薄膜合金的磁各向异性SCIEI

用RF溅射方法在不同的基片温度下制备了非晶态和晶态NdFeB溥膜合金。研究了薄膜合金的磁各向异性。在600℃溅射得到的晶态样品具有强的垂直各向异性和高的矫顽力。由非晶态晶化得到的晶态合金也呈现了较强的垂直各向异性。     

大型薄壁组焊椭圆封头尺寸及变形的控制工艺

叙述了在压力容器制造中,当简体组装、封头分片压制后,焊接大型薄壁椭圆封头,其尺寸和角变形量的控制工艺。     

松香基咪唑啉的合成及其性能的研究

 以松香和多乙烯多胺为原料合成了松香基咪唑啉(ORI)。并通过正交实验，对影响反应的各个因数进行模拟回归，得出适宜的反应条件：反应温度在230℃～240℃，二乙烯三胺和松香的摩尔用量比为1.6∶1，反应时间为5小时，体系的真空度2.67 kPa～5.33 kPa.     

C25型摩擦焊机在刀具焊接方面的应用

针对生产刀具规格和材料品种较多的情况,就C25型摩擦焊机代替闪光对焊机应用在刀具焊接上进行了一系列工艺调试和生产应用,认为摩擦焊机焊接性能优于闪光焊机。     

热采注汽管线的腐蚀与安全性分析

对两段注汽管材料进行了宏观检察、化学成分、壁厚 与管径测量、光学金相组织、常温机械性能、断口扫描电镜、能谱元素等试验分析.结果表明，注汽管材料的局部腐蚀主要是氧化-氯化腐蚀.强度校核表明，两段注汽管目前的壁厚已不能满足内压P=172 MPa、温度T=354℃的使用条件.     

含硅量及等温时间对奥贝球墨铸铁机械性能的影响

探讨了含硅量及等温时间对奥贝球铁冰冷处理前后机械性能及低温冲击韧性的影响。试验表明,随着含硅量的增加,不但冷处理前常温机械性能提高,而且冰冷处理后的机械性能及低温冲击韧性也提高。而含硅3.39％和3.68％的机械性能已趋一致,等温时间为120分钟的试样,冰冷处理前后的机械性能和低温冲击韧性均最高。     

NUMERICAL STUDY OF HYDRODYNAMICS OF MULTIPLE TANDEM JETS IN CROSS FLOW

The hydrodynamics of a single jet and four tandem jets in a cross flow are simulated by using the Computational Fluid Dynamics (CFD) software Fluent. The realizable model is used to close the Reynolds-Averaged equations. The flow characteristics of the jets, including the jet trajectory, the velocity field and the turbulent kinetic energy are obtained with various jet-to-cross flow velocity ratios in the range of 2.38-17.88. It is shown that a single jet penetrates slightly deeper than the first jet in a jet group at the same , although the difference decreases with the decrease of . It is also found that the way in which the velo-city decays along the centerline of the jet is similar for both a single jet and the first jet in a group, and the speed of the decay increases with the decrease of . The downstream jets in a group are found to behave differently due to the sheltering effect of the first jet in the group. Compared with the first jet, the downstream jets penetrate deeper into the cross flow, and the velocity decays more slowly. The circulation zone between the two upstream jets in the front is stronger than those formed between the downstream jets. The Turbulent Kinetic Energy (TKE) sees a distinct double-peak across the cross-sections close to each nozzle, with low values in the jet core and high values in the shear layers. The double-peak gradually vanishes, as the shear layers of the jet merge further away from the nozzle, where the TKE assumes peaks at the jet centerline.