【作者】 王利；

【导师】 杨卫华；

【作者基本信息】 南京航空航天大学 ， 制冷与低温工程， 2009， 硕士

【摘要】 航空发动机燃烧室壁面冷却结构的设计是燃烧室设计技术的重要组成部分,其设计的合理与否将直接影响燃烧室的性能与可靠性。燃烧室壁面复合冷却技术是一种新型的冷却技术,它主要包括冲击+发散冷却技术、冲击对流+气膜冷却技术等。与传统的气膜冷却相比,该技术具有燃烧室壁面温度场均匀,能在较小的冷却气流流量下获得较低的燃烧室壁温,因此在航空发动机燃烧室壁面冷却结构的设计中具有广泛的应用前景。论文首先采用数值模拟和实验研究相结合的方法对冲击+发散冷却结构的流场、温度场进行了分析研究,在此基础上得到了气动参数和几何参数对冲击+发散冷却结构综合冷却效率的影响规律。研究发现,随着吹风比的增大,由发散孔流出的冷却气流会深入主流中,此外在发散孔出口处存在一对旋转方向相反的涡;发散孔的倾斜角对冷却效率有很大的影响,一般而言,发散孔的倾角越小,则冷却效率越高;发散孔叉排时的冷却效率要优于顺排的冷却效率;在相同的流向间距比下,展向间距比越小,则冷却效率越高;而对于冲击发散冷却结构,在本文所研究的范围内,冲击间距对冷却效率的影响不大。然后,论文以浮动瓦块冲击+发散冷却结构为对象,在对其温度场进行分析的基础上使用有限元软件对其应力特性进行了研究,获得应力和变形随吹风比的变化规律。最后,论文针对冲击+逆向对流(有扰流柱)+气膜冷却结构的流场及温度场进行了分析研究,在此基础上分别得到了吹风比、扰流柱排数、扰流柱排列形式以及冲击间距等参数对冷却效率的影响规律。研究发现,扰流柱排数对综合冷效的影响不明显,叉排的冷却效率高于顺排,并且这种优势随着吹风比的增大而增大;冲击间距对冷却效率有一定的影响,一般而言,冷却效率随冲击间距的减小而增大,但在本文研究的范围内,在吹风比较小的时候,冲击间距H=3㎜时的冷却效率要高于冲击间距H=4㎜、5㎜的冷却效率,但是当吹风比M>1.0时,冲击间距H=4㎜和H=5㎜模型的冷效近于一致。更多还原

【Abstract】 Design of Combustor liner wall cooling structure is very important in combustor design,whether to have a successful design will have important impact on the performance and reliability of combustor.Liner wall compound cooling is a kind of novel cooling technology,which includes impingement+effusion cooling,impingement+convection+film cooling etc.In contrast with traditional film cooling,it has uniform temperature distribution and lower wall temperature with less cooling air flow rate, so it is very prospective in gas turbine combustor wall cooling configuration design.Flow field and temperature distribution in Impingement+effusion cooling structure are studied through numerical simulation and experiment method,and get the relations between cooling efficiency and aerodynamic,geometry parameters.It shows that the cold air flow coming from effusion holes will inject into mainflow and there is a pair of opposite swirling vortexes at the exit of effusion holes;The inclination angle has important effects on cooling efficiency,generally speaking, reducing the inclination angle could increase the cooling efficiency;staggered placement is better than aligned arrangement;for given streamwise space ratio,the shorter cross space ratio is ,the higher the cooling efficiency is;with respect to impingement+effusion compound cooling configuration,impingement distance has nothing to with cooling efficiency in this paper’s parameter.Based on the temperature distribution in floating tile impingement+effusion cooling structure,thermal stress distribution is studied using finite software,and get some conclusions that thermal stress and deformation vary with blowing ratio.At last, A numerical study is performed to investigate the flow and temperature fields for impingement + reversed convection(with fin-pins) + film cooling configuration,and get the rules how blowing ratio,number of rows of fin-pins,pattern of placement,impingement distance impact cooling efficiency respectively. It shows that the number of rows of fin-pins has little impact on cooling efficiency,staggered placement is better than aligned arrangement,and the advantage grows bigger as blow ratio increases;impingement distance has certain impact on cooling efficiency,generally speaking,cooling efficiency grows bigger as impingement distance is reduced.,the configuration whose dimensionless impingement distance is 2.14 has the biggest cooling efficiency.When blowing ratio is bigger than 1.0,there is nearly no difference between configuration with dimensionless impingement distance 2.86 and that with3.57.更多还原