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直射流稳焰技术及其燃烧室设计方法研究

Research on Fire Stability of Straight Jet and Relevant Combustor Design Method

【作者】 陈伟

【导师】 雷雨冰;

【作者基本信息】 南京航空航天大学 , 航空宇航推进理论与工程, 2014, 硕士

【摘要】 随着航空技术的发展,微型和小型涡轮发动机的应用日益广泛,作为发动机的核心部件的燃烧室,必须提高其设计水平。燃烧室设计水平的提升需要加深对燃烧室内部流动和燃烧现象的理解和借助先进的设计手段。因此,本文针对微型和小型燃烧室,从火焰稳定机理入手,进行了直射流稳焰技术及其燃烧室的设计方法研究,主要有以下几方面工作:1、从理论上定性分析了火焰稳定的条件,并通过数值计算和可视化的试验手段分析了微型蒸发管式燃烧室的火焰稳定机理,结果表明合理设计火焰筒头部孔射流的位置和强度在燃烧室头部形成回流区是火焰稳定的关键,它充当了点火源,并在蒸发管射流边缘形成火焰前锋,火焰前锋随燃烧室流量增大往回流核心区内缩;火焰筒头部温度分布呈现蒸发管出口温度低,上下回流区温度高等特点;结合数值计算和试验结果分别建立了微型蒸发管式燃烧室和小型环形回流燃烧室定性分析模型,并对火焰形成、发展和稳定机理进行了分析。2、对微型燃烧室初步方案设计系统进行了研究,基于Microsoft Excel建立了经验设计、一维计算和三维参数化建模三个模块。经验设计模块参考现有的主燃烧室设计经验方法,并开展试验研究了某些设计参数对燃烧室性能的影响,以获取相关的经验参数范围,试验结果表明增大燃烧室外环流量分配比例有利于提高燃烧效率,且随着外环流量分配比例的增大,燃烧室出口OTDF先增大后降低;蒸发管流量分配比例K取4.5较为合理。一维计算模块发展了基于压力修正的流体网络法计算程序。三维参数化建模模块采用UG/GRIP语言进行开发。该初步设计系统能有效的提高设计效率。3、利用该初步设计系统对微型燃烧室MTE-170进行了设计,设计了单涡、对称反向双涡和头部切向流三种不同头部方案,在数值计算的指导和改进下,结果表明这三种方案都满足了设计要求,燃烧效率都达到96%以上,总压恢复系数都达到95%以上。4、通过数值模拟,比较了两种环形回流燃烧室A和B,燃烧室B有大弯管结构而A没有,结果表明燃烧室B性能优于燃烧室A的性能。在此基础上,保持燃烧室A的进出口尺寸和机匣尺寸不变的情况下,主要对火焰筒进行了重新设计,计算结果表明重新设计后的燃烧室性能得到了提升,总压恢复系数由94.2%增大为95.4%。

【Abstract】 With the development of aero technology, micro turbine engine and small gas turbine engine areapplied more and more widely. Combustor, as one of the key engine components, its design levelmust be improved. The improvement of design level depends on understanding the inner flow andcombustion phenomenon in combustion chamber deeply and the aid of advanced design tools.Therefore, the paper takes a research on fire steady of straight jet and relevant combustor designmethod for micro and small combustor. The research includes:Analysis the fire steady conditions qualitatively in theory and fire steady mechanism throughsimulations and visual experiments. The results indicate recirculation zone as a result of straight jet isthe key of fire steady, it’s a high temperature zone to ignite the fuel and air mixture from vaporizer atthe jet edge and form the fire front, the fire front move towards the core of recirculation zone; Thetemperature of liner dome is low at the exit of vaporizer and high at the center of recirculation zone;Build fire steady analysis model for micro and small combustor.Build a combustor preliminary design system in which design experience parameters,one-dimensional numerical computation and parametric combustor CAD model are studied. Thedesign experience formula module uses existing design experience and some other experience valuesin micro combustor through experiments, the experiments get that with the outer passage flow rateproportion increase, combustion efficiency increases, and combustor outlet temperature distributionOTDF raises and then drops, the percentage of vaporizer air flow rate4.5%is best. One-dimensionalnumerical computation module makes use of network based on pressure correction method, compile acomputation code. Parametric combustor CAD model module employs UG/GRIP to create athree-dimension model.Design the combustor MTE-170with this system, three cases satisfy the demands under theguidance of simulations, the combustion efficiency exceeds96%, the total pressure recover coefficientexceeds95%.Compare with combustor A, combustor B is better in performance. Design a new combustorbased on the size of combustor A, the total pressure recover coefficient of new combustor improves to95.4%from94.2%.

  • 【分类号】V231.2;V233
  • 【被引频次】7
  • 【下载频次】408
  • 攻读期成果
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