The interior heat transfer characteristics of gas turbine blade due to sparse film cooling holes

The film cooling technique is one of the most useful cooling methods. At present, the midchord region of gas turbine blades in an aeroengine often adopt a sparse film cooling technique and impingement cooling technique at the same time. So the interior heat transfer characteristics on the inner side of blades due to the sparse film cooling holes have become a very complicated and interesting problem. In this paper, the heat transfer characteristics of impingement‐cooling have been investigated experimentally. Through lots of experimental data, the effect of flow parameters and geometric parameters on heat transfer characteristics has been studied. Correlation equations obtained show good agreement with experimental data. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(3): 197–207, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20052     

High-order perturbation solutions to a LH2 spreading model with continuous spill

High-order perturbation solutions have been obtained for the simple physical model describing the LH₂ spreading with a continuous spill, and are shown to improve over the first-order perturbation solutions. The non-dimensional governing equations for the model are derived to obtain more general solutions. Non-dimensional parameters are sought as the governing parameters for the non-dimensional equations, and the non-dimensional evaporation rate is used as the perturbation parameter. The results show that the second-order solutions exhibit an improvement over the first-order solutions with respect to the pool volume; however, there is still a difference between numerical solutions and second-order solutions in the late stage of spread. Finally, it is revealed that the third-order solutions almost agree with numerical solutions.     

黄浦江溢油对松浦大桥取水口的风险分析研究

溢油事故频繁发生,对城市水源的取水口安全构成巨大威胁.通过黄浦江二维溢油模型分析,对松浦大桥取水口处的模拟溢油事故进行了风险分析.结果表明:风场是黄浦江溢油事故对松浦大桥取水口产生影响的关键因素,无风条件下溢油对取水口的影响远大于有风条件下,主要原因是有风条件下黄浦江曲折猛狭长的河道形态使得溢油大多被吸附或滞留在了岸边;无风条件下,当上游发生溢油事故时,径流量是溢油到达取水口时间及影响历时的决定性因素,而下游发生溢油事故对取水口的影响与潮汐特性关系密切.该研究可为黄浦江突发性水污染事故的应急决策提供科学依据.     

诺维信生物清洗剂ABR IC在炼油厂的应用研究

介绍了诺维信生物清洗剂石化行业清洗油污染的应用。结果表明:生物清洗剂在清洗各种油污染方面,具有化学品无可比拟的优势,在工业清洗行业具有广泛的应用前景。     

基于CFX的动态斜面式撇油器收油数值仿真

动态斜面式撇油器是溢油机械回收的重要设备,由于工作时水流流速与收油带速度匹配不佳,很难实现理想的收油效率.为掌握动态斜面式撇油器收油机理和过程,提高收油率,应用CFX软件进行对动态斜面式撇油器收油过程建立三维模型,进行量纲分析和仿真,分析了典型收油状态,研究了水流流速与收油带速度的匹配关系.仿真结果表明,在一定水流流速和油膜厚度条件下,不同的收油带速度可引起不同的油面卷起程度,油面卷起程度可定性地衡量撇油器收油状态,验证了收油带速度对撇油器收油状态的影响,得到了水流流速与收油带速度匹配公式,可为撇油器收油率的提高提供了依据.     

特高压直流单极大地回线运行方式下分流分析及其对策

通过对向家坝—上海±800 kV特高压直流输电工程单极大地回线运行时出现分流现象的分析,得出分流的原因如下:极热备用或极闭锁时因控制逻辑合上旁路开关,导致运行极中性母线与停运极设备形成电流通路.探讨了分流的影响,提出通过运行操作、更改顺序控制或设计分流保护消除分流的措施,有利于提高特高压直流的可靠性.分析结果可为特高压直流工程设计、运行维护提供参考.     

Diversity and community comparison indices: Assessing macroinvertebrate recovery following a gasoline spill

Diversity and community comparison indices were evaluated to determine their utility in quantifying macroinvertebrate response to a catastrophic gasoline spill into Wolf Lodge Creek, Idaho, U.S.A. The Shannon and Brillouin diversity indices, and the following community comparison indices were analyzed: (1) Jaccard's coefficient of similarity; (2) Renkonen's percentage similarity; (3) Bray-Curtis index; (4) Morisita's similarity index; (5) simplified Morisita index; (6) Canberra metric index; and (7) average χ² index. The Bray-Curtis and average χ² community comparison indices were more effective in quantifying differences in macroinvertebrate composition between gas-impacted and reference areas of Wolf Lodge Creek following the spill. In addition, these indices tracked the progressive spatial recolonization of macroinvertebrates during the 16 month recovery period. All other indices tested failed to adequately quantify macroinvertebrate community response to the gasoline spill.     

闽江航道建设对下游敏感目标溢油风险预测

溢油事故是不可逆的环境污染事故,会破坏水体水质,危害生态系统,因而溢油事故的危害不容小觑。闽江下游有多个取水口及湿地保护区,闽江航道施工期及运营期均有溢油事故发生的风险,可能会对环境敏感目标造成影响。根据工程区域情况以及工程建设要求,以二维非稳态模型为平台,建立闽江下游水动力模型,基于实测资料进行模型可靠性分析。在准确的水动力模型基础上,以"油粒子"跟踪技术为指导,建立闽江航道溢油风险预测模型,对闽江下游航道建设施工期及运营期最不利条件下的溢油事故风险进行预测研究,可为闽江应急事故处置、溢油损害评价及取水口的安全管理提供支持和帮助。所提出的溢油事故风险预测方法及思路,能够对溢油事故的积极预防提供一定的参考依据。     

河道型水库溢油费伊模型与油粒子模型的对比研究

针对河道型水库溢油模拟研究匮乏的现状,以龙溪口库区河道突发溢油事故的预测模拟为例,分别建立了传统费伊(FAY)模型及油粒子模型,力图探明这两种主流模型在求解狭长河段溢油扩散时的特性。研究结果表明:FAY模型侧重于油膜扩展阶段中油膜厚度的精细模拟,但在水文情势复杂的河道溢油模拟过程中没有有效考虑流场、风场、地形对油膜漂移、扩散的影响;油粒子MIKE21-OS模型则克服了上述不足,对于河道溢油的模拟具备一定精度。模拟结果可为龙溪口库区突发溢油事故的预测预警提供参考。