Yan Jia, Li Ruixin, Wang Chen
School of Civil Engineering and Architecture, Southwest University of Science and Technology, Mianyang 621010, China.
School of Control Science and Engineering, Shandong University, Jinan 250061, China.
Entropy (Basel). 2022 Dec 21;25(1):15. doi: 10.3390/e25010015.
In this paper, three key geometrical dimensions such as XL3 (constant pressure mixing chamber length), D5 (diameter of the throat of the ejector), and XL5 (length of the throat of the ejector) were separately or sequentially optimized under different lengths and angles of two sections of the primary nozzle. Furthermore, shock cluster number and shock chain length or area of low static pressure zone were used to analyze the effect of geometries on ejector performance, which is normally indicated by entrainment ratio (ER, or the ratio between the mass flow rate of secondary flow and the mass flow rate of primary flow). The results show that: (1) the improvement of ejector performance with only optimization of the primary nozzle is quite limited, in comparison, the impact of length and angle of nozzle diverging section on ejector performance is higher than that of converging section; (2) the relative sensitivity of ER to three key dimensions is much higher than that to the angles and lengths of the primary nozzle; (3) with the increase of XL3 and D5, ER needs a larger angle and smaller length of nozzle converging section; (4) the impact of key geometries on ejector performance can be analyzed with the help of shock cluster number and shock chain length or area of low static pressure zone.
在本文中，在主喷嘴两段的不同长度和角度下，分别或依次优化了三个关键几何尺寸，如XL3（定压混合室长度）、D5（喷射器喉部直径）和XL5（喷射器喉部长度）。此外，使用激波簇数量、激波链长度或低静压区面积来分析几何形状对喷射器性能的影响，喷射器性能通常用引射比（ER，即二次流质量流量与一次流质量流量之比）来表示。结果表明：（1）仅优化主喷嘴时，喷射器性能的提升相当有限，相比之下，喷嘴扩散段的长度和角度对喷射器性能的影响高于收缩段；（2）引射比对三个关键尺寸的相对敏感度远高于对主喷嘴角度和长度的敏感度；（3）随着XL3和D5的增加，引射比需要更大的喷嘴收缩段角度和更小的长度；（4）借助激波簇数量、激波链长度或低静压区面积，可以分析关键几何形状对喷射器性能的影响。
