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Comprehensive optimization design of aerodynamic and electromagnetic scattering characteristics of serpentine nozzle

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Chinese Journal of Aeronautics 2021年第3期34卷 118-128页

作者： Yubo HE Qingzhen YANG Xiang GAO School of Power and Energy Northwestern Polytechnical UniversityXi’an 710129China

Comprehensive optimization design of serpentine nozzle with trapezoidal outlet was studied to improve its aerodynamic and electromagnetic scattering performance.Serpentine nozzles with different center offsets and different ratios of the bases of the trapezoidal outlet were generated based on curvature control regulation.Computational Fluid Dynamics(CFD)simulations have been conducted to obtain the flow field in the nozzle,and Forward-Backward Iterative Physical Optics(FBIPO)method was applied to study the electromagnetic scattering characteristics of the nozzle.Guarantee Convergence Particle Swarm Optimization(GCPSO)algorithm based on Radial Basis Function(RBF)neural network was used to optimize the geometry of the nozzle in consideration of its aerodynamic and electromagnetic scattering characteristics.The results show that the GCPSO method based on RBF can be used to optimize the aerodynamic characteristics of the internal flow and the scattering characteristics of the cavity of the serpentine nozzle with irregular outlet.The optimized model has a higher center offset and a lower ratio of the bases of the trapezoidal outlet after optimization compared to the original model.The optimized model leads to a slight change in aerodynamic performance,with a total pressure recovery coefficient increase of 0.31%and a discharge coefficient increase of 0.41%.In addition,the Radar Cross Section(RCS)decreases also by around 83.33%and the overall performance is significantly improved,with a decrease of the optimized objective function by around 38.74%.

关键词： Forward-Backward Iterative Physical Optics(FBIPO) Guarantee Convergence Particle Swarm Optimization(GCPSO) Nozzle design Optimization design Radar Cross Section(RCS) Serpentine nozzle

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Theories and methods for designing hypersonic high-enthalpy flow nozzles

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Chinese Journal of Aeronautics 2022年第1期35卷 318-339页

作者： Yunpeng WANG Zonglin JIANG State Key Laboratory of High Temperature Gas Dynamics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Hypersonic high-enthalpy wind tunnels have been a challenge to ground tests in aerospace research area for decades and its test flow uniformity is one of the most important parameters for evaluating wind tunnel performances.Regarding to the performance requirement,theories and methods for designing hypersonic flow nozzles at high enthalpy conditions are quite difficult,but very interesting topics,especially when air molecule dissociations take place in wind tunnel test gas reservoirs.In this paper,fundamental theories and important methods for Nozzle designs are briefly reviewed with the emphasis on two-dimensional axisymmetric nozzles for hypersonic high-enthalpy wind tunnels,including the Method of Characteristics(MOC),the graphic design method,the Sivells method,the theory for boundary correction,and the CFD-based design optimization methods.These theories and methods had been proposed based on several physical issues,respectively,which play important roles in nozzle flow expansion processes.These issues cover the expansion wave generation and reflection,the boundary layer development,the real gas effect of hypersonic high-enthalpy flows.Difficulties arising from applications of these methods in hypersonic high-enthalpy Nozzle design are discussed in detail and the state of the art of the Nozzle design technologies that have reached for decades is summarized with some brief comments.Finally,the prospect for the hypersonic Nozzle design methods,and its numerical and experimental verifications are provided with from authors’viewpoint for readers’reference.

关键词： Boundary layer correction High-enthalpy flow Hypersonic wind tunnel Nozzle design Real-gas effects

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维普期刊数据库

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New method for measuring diesel nozzle orif ice inlet structures based on synchrotron X-ray tomography

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Chinese Optics Letters 2014年第8期12卷 32-36页

作者：李治龙吴志军高雅龚慧峰黄魏迪朱敏靖李理光 School of Mechanical Engineering Tongji University School of Automotive Studies Tongji University

Spray behavior is regarded as one of the main factors influencing engine performances, fuel consumption and emissions for diesel engines. Under high injection pressure, diesel spray behaviors are extremely sensitive to the nozzle internal geometries, especially the geometric structures of orifice entrance. Based on the synchrotron radiation X-ray tomography technique, the 3D digital models of nozzle tips can be constructed. A new automatic method is presented to reveal the inlet structures according to these nozzle orifice models. The planes passing through the orifice axis are determined and used to cut the models, and then the corresponding cutting images are applied to measure the inlet chamfer radii around the orifice axis automatically. The orifices of a single-hole nozzle and an eight-hole nozzle are measured according to this method. The results show that this method can automatically measure the orifice inlet chamfer radii around the orifice axis with high precision. The obtained inlet chamfer radius shows the whole profile of the orifice entrance, which is a precise feedback for Nozzle designing and manufacturing, and it also provides precise geometrical boundary conditions for the study of spray behaviors.

关键词： Diesel engines Engines Geometry Imaging systems Nozzle design Orifices Synchrotron radiation Synchrotrons Tomography

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Optimization and Application of Oxygen Lance nozzle for 120 t Converter of Pangang

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Journal of Iron and Steel Research(International) 2011年第S2期18卷 190-194页

作者： CHEN Jun1, LIANG Xin-teng1, LIU Rong-di2, ZENG Jian-hua1 (1. Pangang Group research institute Co., L td. Chengdu 611731, Sichuan, China 2. Vnadium-recoverying and steel-making plant of Pangang, Panzhihua 617062, Sichuan, China) Pangang Grp Res Inst Co L Td Chengdu 611731 Sichuan Peoples R China Vnadium Recoverying & Steel Making Plant Pangang Panzhihua 617062 Sichuan Peoples R China

In order to meet the requirement of semi-steel making, the original nozzle was optimized by Vanadium-recoverying and Stee1-making Works of Pangang. And then every parameters of the oxygen lance were assessed according to industrial tests. Results show that, comparing with the original oxygen lance nozzle the new designed one has a better metallurgical effect, the average volume of oxygen and oxygen supply intensity were increased by 774m3/h and 0.19 m3/(t·min) respectively, oxygen consumption was reduced by 1.87m3/t, the blowing time was lowered by 56 seconds, a better dephosphorization effect was obtained by the new one.

关键词： steel-making oxygen-supply strength Nozzle design dephosphorization

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