驻涡燃烧技术分析及其在直径11厘米燃烧室上的应用.docx

南京航空航天大学硕士学位论文
摘要
本文以直径110mm微型涡轮喷气发动机为背景,采用试验研究与数值模拟相结合的方法对微型驻涡燃烧技术进行深入研究,将凹腔驻涡燃烧技术应用到110mm微型燃烧室上,成功设计了采用液体燃料的蒸发管式微型驻涡燃烧室,试验结果表明该燃烧室燃烧稳定,燃烧效率明显高于同型号传统形式微型燃烧室。
首先,本文对所采用的试验研究方法与数值模拟方法进行了验证。在试验研究方法验证方面,减少轴向测量影响的措施是把测量装置固定在机匣上,确保热电偶探头在燃烧室出口的平面上,减少径向测量影响的措施是:在径向高度为14mm布置4个测点,减少周向测量影响的措施是把测温盘每旋转12°测量一次,共转动10次,对出口温度可测量120个点,采用此措施确保测量方法的可靠性。在数值模拟方法验证方面,根据冷态数值模拟结果与试验结果的对比,最大误差不过2%,初步确定了数值模拟的准确性和可靠性。
其次,对4种结构方案和多种气动状态的微型驻涡燃烧试验件开展了系统试验研究和对比分析。4种结构方案包含2种主流进气结构和2种凹腔尺寸,研究结果显示主流进气通道为长孔得到的燃烧性能明显好于圆孔方案;对国外文献给出凹腔比例关系扣除中心轴之后得到新的凹腔比例关系的燃烧室试验件结构能得到较好的燃烧性能。,燃烧效率达到90%以上。
再次,开展了改善微型驻涡燃烧试验件出口温度分布的研究工作。对外环开掺混孔进行了数值模拟与试验研究,结果发现外环和内环开掺混孔不会影响出口温度分布;在前体通道后端添加棘瓣式混合器,结果发现虽然能改善出口温度分布,但是影响了驻涡燃烧的稳定性,降低了燃烧效率。
最后,根据以上综合分析,设计了4种结构方案直径110mm微型驻涡燃烧室。结构方案分别为2种次流出口孔数和2种蒸发管不同放置方向,研究结果显示:出口孔数增加一半与蒸发管45
°斜切式放置有利于燃烧效率的提高。试验结果:新设计的蒸发管式微型驻涡燃烧室的燃烧效率基本在90%以上,与同型号的传统型燃烧室相比,燃烧效率平均提高了近10%,但是总压恢复系数在大空气流量条件下降低了近5%,出口温度分布系数为0. 5~1。关键词:驻涡燃烧技术,凹腔尺寸,微型燃烧室,蒸发管,燃烧性能
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驻涡燃烧技术研究及其在直径 11 厘米燃烧室上的应用
Abstract
On the basis of the 11 cm micro turbine engine, micro Trapped Vortex technology was deeply studied with both experimental and CFD method. Then, Trapped Vortex concept was essfully applied to 11cm bustor and was designed to be a Trapped bustor. The experimental results show that bustor could burn stably adopted liquid fuel and has bustion efficiency than conventional bustor.
Firstly, some test work was done to determine whether experimental and CFD methods adopted by this paper were effective, as for experimental method, the influence of axial factor was considered by fixing measuring devices onto case to make sure that measurement points were paralleled bustor outlet, radial factor was considered by setting 4 measuring points on the height of 14mm, circumferential influence was determined by measuring outlet temperature once every 12 degrees 10 times, thus there would be 120 points of outlet temperature, then a reasonable measuring program was determined. On CFD work of cold conditi