【作者】 李彬；

【导师】 吉洪湖； 江义军；

【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， 2008， 博士

【摘要】 随着现代航空发动机性能的飞速提升,各种新颖的燃烧室火焰筒冷却方法和结构形式不断涌现,冲击-致密微孔浮动壁火焰筒冷却技术就是其中之一。本文对该技术开展的研究包括四个方面。首先,对冲击-致密微孔浮动壁复合冷却方式的基础流动与换热特性进行了详细的实验研究,研究了冲击-致密微孔壁当量孔流量特性、致密微孔壁冷侧冲击换热、气膜侧对流换热、孔内对流换热以及气膜绝热冷却效率等。实验中考虑了多个气动和结构参数对流动和换热的影响,分析了该复合冷却方式流动与换热的变化规律,并根据实验数据总结拟合了换热经验准则关系式。其次,分别对采用冲击-致密微孔浮动壁冷却方式的单头部燃烧室和全尺寸环形燃烧室的火焰筒壁面冷却效果进行了研究。通过单头部燃烧室实验,分析对比了多种孔配置的冲击-致密微孔浮动壁的冷却效果,为筛选具有最佳综合冷效的浮动壁结构奠定了基础。环形燃烧室的实验完全模拟发动机的工况,验证了冲击-致密微孔浮动壁结构的冷却效果。然后,通过数值模拟,采用ANSYS软件的热分析模块,结合本文基础传热实验和相关文献资料的换热准则关系式进行了冲击-致密微孔浮动壁三维壁温计算,并将计算结果与试验结果进行了比对分析。最后,本文就如何将冲击-致密微孔浮动壁这一新颖的火焰筒冷却技术可靠有效地运用到高性能航空发动机上进行了简要的展望,提出了一些研究建议。本文的研究表明:a.冲击-致密微孔浮动壁火焰筒冷却技术的冷却用气量较少,冷却气量仅为火焰筒总进气量的18%~20%;火焰筒壁温较低,均不高于900℃;壁温梯度较小,在一个瓦块上沿流动方向最大的温差约为200℃左右,远比一段缝槽气膜冷却的壁温差要小。b.影响冲击-致密微孔浮动壁综合冷却效果的因素很多,这些因素相互矛盾和制约。所以在实际应用中,冲击-致密微孔浮动壁冷却结构的参数配置应灵活选取和调配,以利于与燃烧室的其它设计性能参数相匹配。c.浮动瓦块三维壁温场计算方法具有工程适用性,快捷方便,具有较高的计算精度,可为火焰筒壁的强度和寿命预估提供必需的基础数据,有助于航空发动机主燃烧室设计体系的完整建立。总之,冲击-致密微孔浮动壁火焰筒冷却技术是一种高效的冷却技术,对于高性能航空发动机研制具有重大的潜在应用价值。更多还原

【Abstract】 With the rapid development of modern aeroengine, various novel cooling methods and configurations of combustor flame tube have been developed. The impingement/effusion cooling float-wall (I/ECFW for short) flame tube is one of the most prospective configurations.In this thesis four main research works are conducted. Firstly, an experimental investigation of flow and heat transfer process of I/ECFW composite cooling is studied. The discharge coefficient of the equivalent holes, impingement heat transfer coefficient on the cold side of the effusion wall, convective heat transfer on film side of effusion wall and inside effusion holes, and adiabatic wall film cooling effectiveness are studied in details. The empirical formulas of heat transfer are correlated based on the experimental data.Secondly, the cooling effectiveness of a single swirler sector combustion chamber and a full size annular combustion chamber are experimentally studied respectively. Both combustion chambers adopt the I/ECFW cooling method. By the former experiment, the cooling effectiveness of several combinations of impingement holes and effusion holes are compared. This study lays the foundation for optimizing the cooling configuration. The latter experiment is carried out under the real engine condition to validate the cooling effectiveness.And then, the three dimensional temperature field of the I/ECFW is numerically calculated by using the heat analysis module of ANSYS code. The results show a reasonable agreement with the experimental data.At last, the prospect of how to reliably and efficiently use I/ECFW composite cooling technique on high performance aeroengine are discussed. Some suggestions are arisen.The main results of the study are as follows,1. The I/ECFW flame tube requires less cooling air, which is only about 18%~20% of the total inlet flow rate of the flame tube. The temperature of flame tube is less than 900℃. Temperature gradient is relatively small. For a float-wall tile the maximum temperature difference in the flow direction is about 200℃that is far smaller than the corresponding film slot cooling flame tube.2. There are many factors that influence cooling effectiveness of the I/ECFW configuration. These factors often have conflict effect and act against each other. So the I/ECFW configuration should be designed and adjusted carefully. 3. The calculation method for 3D temperature field of float-wall tile is feasible for engineering use, which has reasonable accuracy and can provide the required data for estimating the intensity and life span of flame tube.更多还原