冲压发动机试验面内小位移高精度摄影测量方法

针对冲压发动机试验滑动密封段受噪声和背景强光干扰导致标记或散斑图像相关性损失,而传统的DIC算法不能很好工作的问题,提出了一种面内水平和垂直位移的高精度、高鲁棒且高效的测量方法。首先,采用Canny算子对标记图像滤波后进行拉格朗日插值;然后,对插值后图像进行亚像素阈值分割,并取ROI区域进行形态学闭运算寻找标记轮廓,实现了亚像素级边缘检测;最后,采用一阶中心矩法计算相对位移,得到了精确的亚像素位移值,并基于卡尔曼滤波法提升了位移测量的精度。结果表明:该方法保持了空域亚像素图像的测量速度,在当前配置计算机上获得了较好的鲁棒性和150帧/s的执行效率,使用卡尔曼滤波后测量精度提高了约3倍。

中国超燃冲压发动机研究回顾

回顾了中国近年来在超燃冲压发动机领域的研究进展。首先是高超声速进气道的研究进展,包括高超声速进气道中激波与附面层干扰、起动和再起动、隔离段、进气道附面层抽吸、进气道通道内外压缩比、侧压式进气道、Busemann进气道等。其次是超声速燃烧方面的研究及模型超燃冲压发动机研究。最后对研究工作进行了评述。

EFFECTS OF INCOMING FLOW ASYMMETRY ON SHOCK TRAIN STRUCTURES IN CONSTANT-AREA ISOLATORS

To simulate the actual flowfield at the exit of the supersonic/hypersonic inlet, a wind tunnel is designed to study the flow in the scramjet isolator under the asymmetric incoming flow. And compression fields in the isolator are investigated using wall static and pitot pressure measurements. Three incoming Mach numbers are considered as 1.5, 1.8 and 2. Results show that the increase of the asymmetry of the flow at the isolator entrance leads to the increase of the shock train length in the isolator for a given pressure ratio. Based on the analysis of the flow asymmetry effect at the isolator entrance on the shock train length, a modified correlation is proposed to calculate the length of the shock train. Predicted results of the proposed correlation are in good agreement with the experimental data.