采用CFD和IR综合计算分析的方法，研究了不同结构参数的二元弯曲混合管对红外抑制器性能的影响。计算结果表明：与矩形出口的二元弯曲混合管相比，波瓣型面的混合管出口增加了排气出口周长，依靠粘性和剪切力的作用实现剪切混合，二次引射能力增强，抑制器整体引射性能最大提高了19.2％。同时，混合管壁面温度也显著降低，抑制器垂直方向上3~5 μm波段的红外辐射强度峰值最高降低了13.3％；在波瓣瓣高一定时，随着波瓣数增加，红外抑制器整体引射系数先增大后减小，而总压恢复系数先减小后增大；在波瓣瓣宽一定时，随着瓣高增加，红外抑制器引射系数逐渐增大，而总压恢复系数逐渐减小，辐射强度峰值最大降低了11.6％。

Based on general CFD/IR numerical simulations, the effects of two-dimensional curved mixing duct geometric parameters on helicopter aerodynamics and infrared radiation characteristics were investigated. Conclusions can be drawn as follows according to the computational results: Compared with two-dimensional curved mixing duct with rectangular outlet, the distorted configurations of mixing duct lobed rectangular outlet extend the perimeter of exhaust exit, thus the strength of the secondary flow shed by lobes is enhanced due to the effective shear-mixing caused by viscous and shear force, which contributes to a maximum increase about 19.2％ in pumping capacity of the overall IR suppressor. Simultaneously, wall temperature of mixing duct is reduced significantly and the maximum infrared radiation intensity is decreased about 13.3％ to its highest when changing the shape of mixing duct outlet from rectangle to rectangular lobe. When the lobe heights of mixing ducts remain unchanged, with the increase of lobe numbers, the pumping ratio of IR suppressor firstly increases then decreases, while the total pressure recovery coefficient firstly decreases then increases. In addition, when the lobe numbers of remain unchanged, with the increase of lobe heights, the pumping ratio rises gradually, but the total pressure recovery coefficient keeps declining, and in this situation, the infrared radiation intensity peak achieve a maximum decrease about 11.6％.