Film cooling with using the decomposition of an NH_3 cooling stream as a chemical heat sink

来源 :Chinese Science Bulletin | 被引量 : 0次 | 上传用户:Dustin65928
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The inlet temperatures of gas turbines are generally increasing over time,so conventional cooling methods are likely to approach their useful limits.It is therefore essential to investigate novel cooling methods.Based on the theory of heat transfer enhancement,a novel film cooling method for gas turbine blades using a chemical heat sink is proposed.In this method,the endothermic reaction of an NH 3 cooling stream heated by the main gas stream takes place,reducing the convective heat transfer between the mainstream and the blades.Therefore,film cooling effectiveness is improved.To test the feasibility of the proposed method,numerical simulations were conducted,using the classical flat plate with a 30 degree angled cylindrical hole(diameter,D).Film cooling effectiveness at different blowing ratios(M = 0.5,1.0,and 1.5) were computed and compared with the results of conventional cooling methods.The simulation results show that the proposed method can enhance film cooling effectiveness not only in the stream-wise direction,but also in the span-wise direction.The span-averaged film effectiveness is improved in the presence of a chemical heat sink,with the value of X/D(the ratio of downstream distance from the center of the film hole to the diameter of the film hole) increasing downstream of the film hole.The novel film cooling approach showed the best performance at M = 0.5. The inlet temperatures of gas turbines are generally increasing over time, so conventional cooling methods are likely to approach their useful limits. It is therefore essential essential to investigate novel cooling methods. Based on the theory of heat transfer enhancement, a novel film cooling method for gas turbine blades using a chemical heat sink is proposed. In this method, the endothermic reaction of an NH 3 cooling stream heated by the main gas stream takes place, reducing the convective heat transfer between the mainstream and the blades. improved.To test the feasibility of the proposed method, numerical simulations were conducted using the classical flat plate with a 30 degree angled cylindrical hole (diameter, D) .Film cooling effectiveness at different blowing ratios (M = 0.5, 1.0, and 1.5 ) were computed and compared with the results of conventional cooling methods. the simulation results show that the proposed method can enhance film cooling effectiveness not only in the stream-wise direction, but also in the span-wise direction. span-averaged film effectiveness is improved in the presence of a chemical heat sink, with the value of X / D (the ratio of downstream distance from the center of the film hole to the diameter of the film hole) downstream downstream of the film hole. The novel film cooling approach showed the best performance at M = 0.5.
其他文献
遵守场所秩序要准时入场,以免在到达时打扰他人。如迟到了,要在管理人员指点下入场。进场后按规定对号入座。比赛开始前奏国歌时要起立,高声合唱或保持肃静,不能随意谈笑或做
教学·研究在新课改理念的感召下,我力求改变自己,在继续改进教学方法的同时,比较重视非智力因素在教学中的作用,坚持用自己真诚的微笑、民主平等的作风和丰富的情感等去鼓舞
计步器和加速器为基础的体力活动监测器是目前快速而准确地评估体力活动能量消耗的有效的新方法。这些仪器在科学研究和现场调查中被广泛地采用。但这些仪器型号、功能、结构
在幼儿教育的过程中,为了让幼儿形成良好的礼仪习惯,让其成为有素质懂礼貌的人,就需要实施礼仪教育。礼仪教育能够有效的提升幼儿教育的质量和水平,且还能促使幼儿教育获得最大化的效益。因此本文对幼儿教育中礼仪教育的重要性与实施方法进行了深入的研究,分析了幼儿教育中礼仪教育的重要性,从而提出了幼儿教育中礼仪教育实施的方法和策略。  【关键词】幼儿教育;礼仪教育;重要性;实施方法  1 幼儿教育中礼仪教育的重
据《Энергетика》2011年7-8月刊报道,白俄罗斯国立技术大学的专家分析了高温对蒸汽管道以及高压和中压汽轮机部件强度特性的影响。给出了扩散蠕变和温度的关系图,
技术是施工的关键,建筑施工中会涉及到多种施工技术,比如混凝土施工技术、地基处理技术、钢筋焊接技术等,但所有这些技术中,最为关键的还是混凝土施工技术。正确运用混凝土施
科举和高考在推动历史前进的同时,也颠覆了教育的本质,使之沦为考试的工具。历史发展到今天,高考也日渐显露出其落后性,必须对其进行否定之否定,才能进入更高的教育境界。高
泸州是四川省八个国家级历史文化名城之一,是川南最具多元文化特征的历史文化名城,受古蜀文化、巴文化、夜郎文化、僰文化影响而形成独特的泸文化。本文对泸州“江与城”古文
为探讨PC、PS在恶性肿瘤诊治中的应用价值,本文测定了92例恶性肿瘤患者的PC、PS抗凝活性。结果:PC:A以肺癌组为最高;肝癌组最低,与正常对照组比较P均<0.01。其他癌症组与正常组比较
随着新一轮课改的实施,学生学习方式的转变是基础教育改革的核心,也是我国本次课程改革在实施过程中的重要体现.全国各地的一线教师都在努力为新课改做着各种各样有益的尝试,