排气引射器是船用燃气轮机降低排气温度，有效减弱红外信号强度，保证船舶隐身性的关键设备之一。目前，船用燃气轮机大多沿轴线方向布置于机舱底部，排气需要经过转弯后向上排出，因此喷口处呈现较大的速度梯度，影响排气引射装置的性能。此外，为达到较好的引射性能常在喷口处加入突片结构加强掺混，而流向涡产生于突片后，有助于气流的掺混。本课题针对不同结构参数的排气引射器，提出喷口处速度梯度的评价指标，建立结构参数与速度梯度和引射性能的数学关系，并通过流场实验进行验证。采用基于有效阻塞面积比的流向涡评价方法，分析引射性能的变化规律，并利用粒子图像测速方法测量突片后流向涡的变化。本课题研究成果不仅会促进船用燃气轮机排气引射器性能提升，而且对船用燃气轮机的装船应用起到积极的作用。

The exhaust ejector of marine gas turbine is one of the key equipment to reduce the exhaust temperature, weaken the infrared signal intensity and ensure the infrared stealth. Currently, most of marine gas turbines are arranged along the axial direction at the bottom of the cabin, and the exhaust gas needs discharged after turning upward. There will be a large velocity gradient of nozzle behind swerve exhaust pipe, and the performance of exhaust ejector will be affected. In addition, the nozzle with tabs structure is usually used to improve ejector performance. The streamwise vortexes which can achieve better strengthen blending will be generate behind tabs structure. Different structure parameters of exhaust ejectors will be studied in this project. The evaluation indicator about velocity gradient of nozzle will be presented. And the mathematical relationship between the structural parameters, velocity gradient and ejector performance will be established. The mathematical relationships and simulation accuracy will be verified by experiment. The evaluation method of streamwise vortex based on effective blocking area ratio will be used to study the ejector performance variation rules. The particle image velocimetry will be used to measure the streamwise vortex changes behind tabs structure. The research results will not only improve the marine gas turbine exhaust ejector performance, but also promote the application of marine gas turbine on ships.