矢量偏转对二元塞式矢量喷管红外辐射特征的影响

Effects of Vectoring Deflection on Infrared Signature of Two-Dimensional Wedge Vectoring Nozzle

关键词:  二元塞式矢量喷管  矢量偏转  塞锥  红外特征  涡扇发动机

Key words:  Two dimensional wedge vectoring nozzle  Vectoring deflection  Wedge cone  Infrared signature  Turbofan engine

摘要:

为了研究矢量偏转对二元塞式矢量喷管红外辐射特征的影响，通过喷管缩比模型的红外辐射特征试验，获得矢量偏转对喷管缩比模型红外辐射特征影响的试验数据及规律，并验证了红外辐射特征数值计算方法的计算精度。采用经过验证的计算方法对全尺寸二元塞式矢量喷管在发动机地面工作状态下的流场特性与红外辐射特征进行了数值仿真。研究结果表明：当矢量偏转角由0°增加到20°，塞锥壁面温度分布基本不变，但喷管偏转压力侧壁面温度逐渐升高，最大增幅达到38.5%，喷管偏转吸力侧壁面温度逐渐下降，最大降低15.4%。塞锥是二元塞式矢量喷管最主要的红外辐射源，在尾向-20°~20°方向，塞锥的平均贡献≥63.6%，最大高达91.0%。随着偏转角增加，喷管在水平探测面内的红外辐射强度逐渐减小，其中正尾向上的降幅最大，达到33.6%；在铅锤探测面内，辐射峰值方向朝矢量偏转方向偏移，但偏移角度小于矢量偏转角度。全尺寸模型仿真获得的矢量偏转对喷管红外辐射特征分布的影响规律与缩比模型试验的结论一致。

Abstract:

In order to investigate the effects of vectoring deflection on the infrared （IR） signatures of Two-Dimensional Wedge Vectoring Nozzle （2-D WVN）， firstly， an experiment was carried out with a subscale 2-D WVN to obtain experimental data and change laws of IR signatures effected by vectoring deflection， and validate the accuracy of the numerical method used in this paper. Then， numerical analysis of full-scale model in ground state was further taken for the flow and infrared characteristics. The results exhibit that， the wall temperature of wedge cone was almost unchanged while the vectoring deflection angle altered within the range of 0° ~ 20°. However， it had a great impact on both the temperature on pressure side and suction side of the nozzle， which could make an increase up to 38.5% and a reduction down to 15.4%， respectively. The wedge cone was the dominating IR source for 2-D WVN. In the range of -20° ~ 20° for tail deflection angles， the average infrared intensity of the wedge cone accounted for a ratio over 63.6% to the total， which can even be up to 91.0%. With the increase of deflection angles， the infrared radiation intensity of 2-D WVN decreased gradually from the horizontal detection view. The maximum drop reached 33.6% when the detection angle was 0°. In the vertical detection plane， the direction of the radiation peak shifted towards the vectoring deflection direction， and the offset angle was smaller than the vectoring deflection angle. Furthermore， conclusions about change laws of IR signatures achieved by full-scale model’s numerical analysis were consistent with those explored by subscale model’s experimental measurement.