【作者】 宫禹；

【导师】 吉洪湖；

【作者基本信息】 南京航空航天大学 ， 工程热物理， 2007， 硕士

【摘要】 本文以研制涡扇发动机排气系统红外隐身实验装置为目的,进行了实验装置的方案设计研究及其在安装轴对称混合排气形式喷管情况的红外特性的仿真。研究工作主要通过数值模拟来完成,其中,物理模型的建立用Unigraphics软件进行,网格划分采用Gambit软件进行,流场计算采用FLUENT软件进行,红外辐射特征的计算采用本课题组发展的涡轮发动机排气系统红外辐射强度预估软件TEESIRP(Tturbine Engine Exhaust System Infrared Radiate Prediction)进行。实验装置的总体设计研究主要包括以下内容,分别是:实验装置的方案设计、外涵进气形式设计、关键部件尺寸设计、风机选型和流场参数测量设计。该部分工作的特色和优点在于大量利用CFD计算来辅助设计,运用FLUENT软件计算了多种外涵进气形式下外涵截面的速度分布,并对计算结果进行比较以确定了符合实验装置设计要求的外涵进气形式设计;运用FLUENT软件计算了实验装置的关键部件不同主要尺寸参数组合情况下的外涵截面速度分布,并对计算结果进行比较确定了符合实验装置设计要求的关键部件尺寸;运用FLUENT软件计算了在内涵、外涵流量符合实验装置设计要求的情况下对风机提供动压的需求,进而根据设计余量修正及风机厂提供的多个型号风机的性能曲线选择了适合实验装置设计需求的风机型号。通过该部分研究为即将展开的实验装置零部件设计、及零部件组装设计打下了坚实的基础。实验装置红外特性仿真研究中,计算了其在安装轴对称喷管情况下的红外特性。计算的工作包括流场计算和红外计算两个步骤,首先运用FLUENT软件计算了在安装不同喷管情况下,实验系统的温度场、流场和浓度场分布,然后运用TEESIRP软件计算了红外辐射强度的光谱分布和空间分布。在完成计算的基础上,从燃气辐射特性分析、流场参数分布、喷管内各个部件投影面积变化等方面论证了计算结果的可靠性以及涡扇发动机轴对称喷管红外强度分布的机理。通过该部分工作预测和分析了实验装置在设计工作状态下的红外辐射特性,为实验研究的展开以及实验现象的分析打下了坚实的基础。更多还原

【Abstract】 The objective of this thesis is to investigate the infrared stealth experiment device of the exhaust system of turbofan engine. The scheme design of infrared stealth experiment device and the Infrared Radiation (IR) behavior of experiment device installed with axisymmetrical convergent nozzle were investigated. On the numerical aspect of the study, the physical models were established with software of Unigraphics, the meshes were created with Gambit, the flow fields were computed with FLUENT. The IR characteristics were computed with an IR analysis software—TEESIRP(Turbine Engine Exhaust System Infrared Radiate Prediction)developed by research group.The overall design work of test equipment includes scheme design for test equipment, by-pass duct inlet design, size design for key components, fan selection and measurement design for flow parameters. The characteristic and advantage of this part is considerable usage of CFD technology and including several key points below. The first, the velocity distribution of by-pass section was calculated for various by-pass inlet forms using fluent software and the calculated results were compared to determine the by-pass inlet form which accords with the test equipment design requirements. The second, the velocity distribution of by-pass section was calculated for the combinations of various key size parameters which belong to key components of test equipment and also the calculated results was compared to determine the coincident design requirements. The last, it was calculated the needed dynamic pressure which the fan provided in the condition that the core and bypass flow rate accords with the design requirements and then fan model was chosen based on residual correction and performance curves of various fans which was provided by the fan company. The above research made good preparation for the forthcoming component design and assembly design.In the research of usage test equipment to simulate the infrared performance, it was calculated the infrared characteristic in the condition of axisymmetric nozzle installed. It was included flow calculation and infrared performance calculation in this part of work. Firstly the temperature filed, flow field and concentration field was calculated through fluent software calculation for various nozzles. Secondly, the spectral and spatial distribution of infrared intensity was calculated in the usage of TEESIRP software. Based on the finished calculation, the result reliability and the mechanism of infrared intensity distribution was demonstrated from the below aspects, analysis of radiation characteristic from gas, flow field parameters distribution, the projected area variation of different nozzle components. The part predicted and analyzed the infrared characteristic of test equipment under the design condition. And it also made good preparation for the development of test work and analysis of test phenomena.更多还原