Experimental study on film cooling performance of imperfect holes

An experimental study is made to investigate the film cooling performance of imperfect holes due to in-hole blockage over a flat plate. A specifically pyramid-shaped element is used to simulate the in-hole blockage. Six in-hole blockage orientations (such as leading-inlet, leading-middle, leading-exit, trailing-inlet, trailing-middle and trailing-exit) and four blocking ratios (ranging from 0.1 to 0.4) are taken into considerations. Based on the experimental results, the influences of in-hole blockage on the film cooling effectiveness and discharge coefficient under typical blowing ratios are analyzed. It is confirmed that the in-hole blockage results in a reduction of discharge coefficient related to the perfect film cooling holes, especially for the leading-exit and trailing-inlet orientations with a big blocking ratio. However, in the view of film cooling effectiveness, the in-hole blockage shows complicated affecting roles. In general, except for the leading-exit orientation, the in-hole blockages produce detrimental influence on the film cooling effectiveness.     

污染空气对氢燃料超声速燃烧室性能的影响

采用纯净空气和污染空气来流下对比试验的方法,研究了飞行马赫数4条件下H2O和CO2污染组分对氢燃料超声速燃烧室性能的影响。对比试验中针对纯净空气来流和污染空气来流匹配了来流总温、总压、氧气摩尔分数和当量油气比。完成了0.53和0.42两种当量油气比条件下纯净空气来流和污染空气来流的氢燃料超声速燃烧试验,预定考察的H2O污染组分摩尔浓度分别有7.5%,18%和26%三种,CO2污染组分浓度有3.0%和7.5%两种。研究结果表明,H2O,CO2或H2O+CO2组合污染对燃烧诱导压升产生了明显的非线性抑制影响,直接将污染试验空气来流下的试验结果外推应用到飞行条件,可能导致供油量偏大、甚至进气道不启动;同时也影响了隔离段内燃烧诱导激波链结构,使燃烧工作模态趋向于超燃模态。     

实验应力分析处理中电子表格应用简介

简述了实验应力分析中电子表格的建立和应用，该表格方式可使数据处理，应力分析简捷明了计算结果形象直观。     

高职高专试点专业建设思路与探索

在探讨高职高专试点专业建设思路基础上,分析了供热通风与空调工程专业在试点过程中的方向、课程设置、实训方式、产学研结合、师资培养以及精品课建设等多方面及各环节的做法,总结了试点专业建设中的经验,提出了促进试点专业进一步改革和发展的方向.     

高职实训教学与职业技能鉴定相接轨的实现

分析了当前阻碍职业技能鉴定与高职教育相统一的三个因素；提出了以职业技能鉴定为核心，以教学改革为契机推动实训教学与职业技能鉴定接轨的改革措施，最终实现高职实训教学与职业技能鉴定的有效结合。     

在常规小风洞中实现大风洞中的气动力实验

就风洞尺寸要多大才比较合理以及小风洞的改造和挖潜等问题进行了讨论。认为风洞尺寸不是越大越好,而是在不同速度范围存在着一组相对适中的带某种唯一性的风洞尺寸。这种风洞尺寸,既能满足航天器研制的需要,又具有合理的经费开支。文中推荐了不同速度下一组较合适的且能满足需要的风洞尺寸,供人们参考。同时本文还认为,在一定的风洞条件下,实验数据的精准度与风洞尺寸的大小无关,只要相似模拟的条件正确,就能给出同样精准度的实验数据。就这一观点,列举了在北京空气动力研究所的FD 02小风洞中做出的几种实验。     

固体火箭发动机药柱3维应力场光弹性实验研究

应用３维光弹性原理和方法，对３种固体火箭发机的不同星槽翼柱型药的几何尺寸分别进行缩比，模型设计及机加型。然后，把这些模型分别在均匀压强作用下进行应力冻结，切片及应力分析。实验结果表明，实验结果与理论值两者吻合很好。     

流体力学综合实验台的开发与应用

以创新型、综合型实验设计为目标,通过对流体力学综合实验台功能的设计与开发,突出其综合应用性和对实践教学效果的促进作用;对实验数据进行分析,说明实验台设计的合理性。     

Selection of candidate salad vegetables for controlled ecological life support system

Higher plants, as one of the essential biological components of CELSS, can supply food, oxygen and water for human crews during future long-duration space missions and Lunar/Mars habitats. In order to select suitable leaf vegetable varieties for our CELSS Experimental Facility (CEF), five varieties of lettuce (“Nenlvnaiyou”, “Dasusheng”, “Naichoutai”, “Dongfangkaixuan” and “Siji”), two of spinach (“Daye” and “Quanneng”), one of rape (“Jingyou No. 1”) and one of common sowthistle were grown and compared on the basis of edible biomass, and nutrient content. In addition, two series of experiments were conducted to study single leaf photosynthetic rates and transpiration rates at 30 days after planting, one which used various concentrations of CO₂ (500, 1000, 1500 and 2000 μmol mol⁻¹) and another which used various light intensities (100, 300, 500 and 700 μmol m⁻² s⁻¹). Results showed that lettuce cvs. “Nenlvnaiyou”, “Siji” and “Dasusheng” produced higher yields of edible biomass; common sowthisle would be a good source of β-carotene for the diet. Based on the collective findings, we selected three varieties of lettuce (“Nenlvnaiyou”, “Dasusheng” and “Siji”) and one of common sowthistle as the candidate crops for further research in our CEF. In addition, elevated CO₂ concentration increased the rates of photosynthesis and transpiration, and elevated light intensity increased the rate of photosynthesis for these varieties. These results can be useful for determining optimal conditions for controlling CO₂ and water fluxes between the crops and the overall CELSS.