| 摘要: |
| 横向射流是降低航空发动机尾喷流在3~5μm波段上红外辐射特征的一种高效低阻的途径。本文以收敛喷管为对象，在喷口下游布置了一对上下对称的扁平横向射流孔，数值模拟研究了两股同频横向射流之间相位差（0°，90°和180°）对下游掺混与红外抑制的影响规律。结果表明，脉动横向射流诱导产生的流向涡强化了掺混，不同横向射流之间的相位差会使涡对出现的时间与空间复杂交错，可以充分卷吸气流，加强尾喷流与外界大气的掺混。而相位差的优化设计可以进一步提高涡对之间的掺混增益，增强红外抑制效果的作用。与Δφ=0无相位差状态相比，随着相位差增大，红外抑制效果逐渐增强。相位差为π时，掺混效果最好，高温区长度降低约14%，红外积分辐射特征最大降幅约13%，光谱辐射降幅最大可达21%，有效增强了对尾喷流的红外抑制。 |
| 关键词: 航空发动机 红外抑制 轴对称收敛喷管 尾喷流 横向射流 强化掺混 |
| DOI：10.13675/j.cnki.tjjs.2207030 |
| 分类号:V231.1 |
| 基金项目:国家科技重大专项（J2019-III-0009-0053）；航空科学基金（20200027052002）。 |
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| Numerical Study on Effects of Transverse Jet Phase Shift on Aerodynamic and Infrared Characteristics of Exhaust System |
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LIN Zi-qiang1, ZHANG Bo1, ZHANG Jun1, YANG Sheng1, LI Wei2, JI Hong-hu1
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1.Jiangsu Province Key Laboratory of Aerospace Power System，College of Energy and Power Engineering， Nanjing University of Aeronautics and Astronautics，Nanjing 210016，China;2.AVIC Shenyang Aircraft Design and Research Institute，Shenyang 110000，China
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| Abstract: |
| Transverse jet is an efficient and low resistance method to reduce the infrared radiation characteristics of aircraft engine plume in the 3~5μm waveband. This paper takes convergent nozzle as the object， and a pair of symmetrical horizontal jet holes are arranged downstream of the nozzle. The effects of phase shift （0°， 90° and 180°） between two transverse jets with the same frequency on downstream mixing and infrared suppression were investigated by numerical simulation.The results show that the flow direction vortices induced by the pulsating transverse jet strengthen the mixing， and the phase shift between different transverse jets makes the vortex pairs appear in complex time and space， which can fully enroll the suction flow and strengthen the mixing between the plume and the outside atmosphere. The optimal design of phase shift can further improve the mixing gain between vortex pairs and enhance the effects of infrared suppression.Compared with the state of Δφ =0 without phase shift， the infrared suppression effect is gradually enhanced with the increase of phase shift. When the phase shift is π， the mixing effect is the best， the length of the high temperature region decreases by about 14%， the infrared integral radiation characteristic decreases by about 13%， and the spectral radiation decreases by up to 21%， which effectively enhances the infrared suppression of the plume. |
| Key words: Aeroengine Infrared suppression Axisymmetric convergent nozzle Plume Transverse jet flow Strengthening mixing |
