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Research on Measurement Method of Muffler Performance under High Temperature and High-Speed Airflow Conditions

Journal of Beijing Institute of technology 2020年第2期29卷 241-250页

作者： Liping Xie Chihua Lu Zhien Liu Yawei Zhu Hubei Key Laboratory of Advanced Technology of Automotive Components Wuhan University of TechnologyWuhan 430070China Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan 430070China

Ignoring the influence of flow velocity and flow temperature on muffling performance,performance tests were conducted without airflow in the development phase of the muffler which accounts to the difficulty of obtaining a perfect match between the actual noise reduction effect and the design *** on the two-load test theory,a set of high-temperature and high-speed airflow simulation measurement devices for the muffler has been *** order to avoid the impact of high-temperature and high-speed airflow on the sensor,a high temperature resistant sensor holder has been designed for the test *** sound pressure has been measured in the pipe by using the lead-out *** addition,a variable impedance load is placed at the end of the test tube to realize the switch between two different impedance loads by the wave handle of the variable impedance load.A sound source correction method is proposed to decrease the random fluctuation of the spectral characteristics of the output noise signal,which is caused by the acoustic impedance variation at the connection between the transition pipeline and the combined sound source ***,an acoustic software has been used to calculate the transmission loss of the muffler in the presence of high temperature *** comparing the experimental measurements and the simulation results,the small difference shows that:the bench not only can effectively simulate high-temperature and flow velocity environment of the engine but also accurately test the transmission loss of the muffler.

关键词： muffler lead-out measurement variable load source correction transmission loss

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TFM imaging of aeroengine casing ring forgings with curved surfaces using acoustic field threshold segmentation and vector coherence factor

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Chinese Journal of Aeronautics 2022年第11期35卷 401-415页

作者： Shanyue GUAN Xiaokai WANG Lin HUA Yixuan LI Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan 430070China School of Automotive Engineering Wuhan University of TechnologyWuhan 430070China

The aeroengine casing ring forgings have complex cross-section shapes,when the conventional ultrasonic or phased array is applied to detect such curved surfaces,the inspection images always have low resolution and even artifacts due to the distortion of the wave *** this article,taking a type of aeroengine casing ring forging as an example,the Total Focusing Method(TFM)algorithms for curved surfaces are ***,the Acoustic Field Threshold Segmentation(AFTS)algorithm is proposed to reduce background noise and data ***,the Vector Coherence Factor(VCF)is adopted to improve the lateral resolution of the TFM ***,a series of 0.8 mm diameter Side-Drilled Holes(SDHs)are machined below convex and concave surfaces of the *** quantitative comparison of the detection images using the conventional TFM,AFTS-TFM,VCF-TFM,and AFTS-VCF-TFM is implemented in terms of data volume,imaging Signal-to-Noise Ratio(SNR),and defect echo *** results show that compared with conventional TFM,the data volume of AFTS-VCF-TFM algorithm for convex and concave is decreased by 32.39%and 73.40%,***,the average SNR of the AFTS-VCF-TFM is gained up to 40.0 dB,while the average 6 dB-drop echo width of defects is reduced to 0.74 mm.

关键词： Aeroengine casing Acoustic Field Threshold Segmentation(AFTS) Curved surfaces Total Focusing Method(TFM) Vector Coherence Factor(VCF)

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The Influence of temperature on the microstructure and properties of Cu/Al tube joints in magnetic pulse-assisted semi-solid brazing

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Journal of advanced Joining Processes 2025年

作者： Zhenglei Rui Shangyu Huang Huajun Wang Zhenghua Meng School of Materials Science and Engineering Wuhan University of Technology Wuhan 430070 China Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of Technology Wuhan 430070 China

This study addresses the technical challenge of copper/aluminum (Cu/Al) tube joining through the innovative application of magnetic pulse-assisted semi-solid brazing (MPASSB) technology. Through an integrated approach combining finite element simulation with microstructural characterization, this study systematically investigates how brazing temperature (390-440°C) influences the microstructure and mechanical properties of Cu/Al tube joints. Notably, a novel finite element method-smoothed particle hydrodynamics (FEM-SPH) coupling model has been developed. This model enables precise simulation of fluid-solid interactions between tubes and filler metal during the brazing process, providing fresh insights into oxide layer removal mechanisms. The research reveals that brazing temperature serves as the critical parameter governing the elemental diffusion and microstructural evolution in the joint. As the temperature increases from 390°C to 440°C, the viscosity coefficient of the filler metal decreases significantly from 41.6Pa·s to 1.798Pa·s, resulting in enhanced fluidity that promotes interfacial interactions between the tubes and filler metal and effectively removes surface oxide films, thus improving joint quality. However, excessive temperature intensifies the filler metal ejection, increasing the risk of filler metal deficiency at the top of the joint. Mechanical testing demonstrates that joints brazed at 440°C achieve optimal shear strength of 81.1MPa, with fracture occurring at the copper-side (Cu-side) interface between the Al 4.2 Cu 3.2 Zn 0.7 intermetallic phase and the diffusion layer. This work establishes fundamental theoretical guidance for optimizing MPASSB process parameters and facilitates the efficient joining of Cu/Al tubes.

关键词： Brazing temperature Finite element simulation Elemental diffusion Oxide removal Interfacial interaction

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Microstructure inheriting evolution and strength-plasticity collaborative improvement mechanism of multidirectional rotary forged Al7075 sheets during T6 heat treatment

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Journal of Materials Science & technology 2024年第36期203卷 14-38页

作者： Xuan Hu Xinghui Han Lin Hua Jishi Zhang Jing Xu Fang Chai Wuhao Zhuang Fangyan Zheng Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China Hubei Longzhong Laboratory Xiangyang 441000China School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

Al7075 sheets are widely used in aerospace industry and their higher strength-plasticity collaborative improvement requirement is *** this study,the microstructure inheriting the evolution and me-chanical properties of Al7075 sheets during multidirectional rotary forging(MRF)and T6 heat treatment are *** results show that the average grain size exhibits near-parabolic evolution with increas-ing MRF deformation ***20%+T6(20%MRF deformation amount+T6)condition possesses the largest grain size of 72.6μm,and its abnormal grain growth mechanism is that the medium deformation energy and high deformation heterogeneity in MRF20%deformed grains could cause asynchronous re-crystallization behavior during T6 heat treatment,and the grains with comparatively higher deformation energy get recrystallized firstly and devour adjacent grains along preferred011or223misorientation ***70%+T6 condition possesses the finest grain size of 14.2μm,and its fine grain inheriting mech-anism is that the uniformly high deformation energy in MRF70%deformed grains causes uniformly rapid recrystallization,and rapidly recrystallized grains effectively suppress grain boundary motion from adja-cent *** increasing MRF deformation amount,tensile strength and elongation values both exhibit near-antiparabolic ***70%+T6 condition possesses the largest tensile strength(563 MPa)and elongation(17.73%),which increases by 8.27%and 80.55%compared to as-annealed+T6(MRF0%+T6)condition(tensile strength is 520 MPa and elongation is 9.82%),*** strength-plasticity col-laborative improvement is mainly because the combination of effectively inherited fine grains,refined inclusion particles,and uniformly distributed fineη’particles after T6 heat treatment could promote smooth dislocation movement and coordinated slip behavior in most matrix grains,which contributes to the delay of stress localization and strength-plasticity collaborative improvement.

关键词： Al7075 sheets Multidirectional rotary forging T6 heat treatment Microstructure inheriting evolution Strength-plasticity collaborative improvement

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An innovative constraining ring rolling process for manufacturing conical rings with thin sterna and high ribs

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Chinese Journal of Aeronautics 2022年第8期35卷 324-339页

作者： Duanyang TIAN Xinghui HAN Lin HUA Xuan HU Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070 China School of Automotive Engineering Wuhan University of TechnologyWuhan 430070China

Conical rings with thin sterna and high ribs(CRTSHR)are key bearing-load parts of aerospace equipment,which are required to be manufactured with high performance and *** ring rolling is the most preferred method for manufacturing high-performance ring parts,but it can hardly achieve the forming of CRTSHR due to the extreme geometry of *** solve this difficulty,an innovative constraining ring rolling process(CRR)is proposed in this paper to manufacture *** evaluate the proposed CRR and reveal its deformation behaviors,a thermomechanical coupled FE model for CRR of CRTSHR is ***,the experiment for CRR of CRTSHR is performed on a modified ring rolling machine,which proves that CRR of CRTSHR is feasible and the established FE model is *** on the reliable FE model,the metal flow mode in deformed CRTSHR is analyzed,and the deformation characteristics such as the stress state,strain distribution and the evolution of power parameters in CRR of CRTSHR are ***,the influences of key parameters such as the friction factor between ring and molds,the diameter of idle roll and the feed velocity of idle roll on CRR of CRTSHR are investigated by FE simulation.

关键词： Conical rings with thin sterna and high ribs Deformation characteristics FE simulation Metal flow Ring rolling

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Mechanical behaviors and energy absorption properties of Y/Cr and Ce/Cr coated open-cell nickel-based alloy foams

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Rare Metals 2018年第8期37卷 650-661页

作者： Zhi-Li Hu Qiu Pang Guo-Qiang Ji Gao-Hui Wu State Key Laboratory of Advanced Welding and Joining HarbinInstitute of TechnologyHarbin 150001China Hubei Key Laboratory of Advanced Technology of Automobile Components Wuhan University of TechnologyWuhan 430070China School of Mechanical and Electrical Engineering Wuhan Donghu UniversityWuhan 430212China Materials Test Department China National Analytical CenterGuangzhou 510070China

In this study, Y-and Ce-modified Cr coatings applied by pack cementation method were prepared on the surface of open-cell nickel-based alloy foam. The morphologies and microstructures of Y- and Ce-modified Cr coatings with various Y and Ce contents were investigated in detail. Then, the effects of Y and Ce addition on the mechanical properties of open-cell nickel-based alloy foams were analyzed and compared. Simultaneously, the energy absorption capacity and energy absorption efficiency of the Y- and Ce-modified Cr coated alloy foams were discussed and compared at the room and high temperatures. The results show that Cr coatings containing minor amounts of rare earth element （Y and Ce） are well adhered to the nickel-based foam struts. Especially, the microstructure of the 2 wt% Ce-modified Cr coating is denser and uniform. In addition, the compressive strength and plateau stress of Y- and Ce-modified Cr coated alloy foams firstly increase and then decrease by increasing the Y and Ce contents at room and high temperatures. The energy absorption capacity of Y/Cr and Ce/Cr coated alloy foams increases linearly with the strains increasing. The Ce/Cr coated alloy foams can absorb more energy than Y/Cr coated alloy foams in the plateau and densification regions at room temperature. Compared to those at room temperature, the Y- and Ce-modified Cr coated alloy foams show higher energy absorption efficiency when deforma- tion within 10%-30% at high temperature.

关键词： Open-cell nickel-based alloy foam Y-modified Cr coating Ce-modified Cr coating Pack cementation Mechanical properties

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Objective Quantification of Small Motor Sound Quality Based on Psychoacoustic Metrics

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Journal of Beijing Institute of technology 2022年第2期31卷 208-223页

作者： Tao Huang Zhi’en Liu Binyu Zhang Jinyan Bi Lipin Xie Auto-motive Engineering Institute Guangzhou Automobile Group(GAC)Guangzhou 511434China Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China.

With the widespread application of electrification and intelligence of automobiles,the number of electric devices with small DC motors in automobiles has gradually increased,and the in-terior of electric vehicles is *** sound quality(SQ)of small motor directly affects the pas-senger ***,the research on the SQ of small motor is of great *** this paper,the objective quantification of small motor sound quality was investigated based on tradi-tional psychoacoustic *** time-frequency characteristics of sound signal was analyzed to quantify the subjective perception caused by the sound of small *** a new psychoacoustic metrics of objective evaluation which were suitable for small motor SQ evaluation were proposed,namely specific loudness energy(SLE),specific prominence ratio index(SPRI),relative pitch exceedance(RPE)and tremolo index(TI).Then,two objective evaluation models of small motor SQ were established to characterize the multi-dimensional subjective perception attributes by using multiple linear regression(MLR)and support vector regression(SVR)respectively,which can be used for the prediction and evaluation of the small motor *** results show that the prediction accuracy of the model established by SVR method was higher than that of MLR,and SVR has stronger *** objective evaluation model of small motors SQ established in this study is of great importance for improving the sound quality of small motors.

关键词： motor sound quality subjective evaluation psychoacoustic metrics support vector re-gression(SVR)

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Segmented current diagnostics for mode switching and fuel cell mode startup behavior in unitized regenerative proton exchange membrane fuel cells

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Energy Conversion and Management 2025年 336卷

作者： Chen, Wenshang Meng, Kai Luo, Zongkai Deng, Qihao Zhang, Ning Chen, Ke Chen, Ben Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of Technology Wuhan430070 China School of Mechanical and Electrical Engineering Wuhan Business University Wuhan430056 China

In dual-mode operation, the unitized regenerative proton exchange membrane fuel cell (UR-PEMFC) experiences complex water–gas dynamics, particularly during mode switching in the constant-electrode (CE) configuration, where hydrogen and oxygen channels can cross-contaminate. Optimizing the mode-switching strategy enhances both round-trip efficiency and the speed and stability of transitions between electrolysis cell (EC) and fuel cell (FC) modes. This study introduces printed circuit board (PCB) segmented current technology for the first time in UR-PEMFC testing, enabling in-situ monitoring of current density distribution in both FC and EC modes. By analyzing the current density distribution and uniformity index under typical mass transfer faults, an in-situ diagnostic system for mass transfer was developed, facilitating optimized mode switching. Results indicated that, despite nitrogen and hydrogen–oxygen purging, FC mode startup was susceptible to flooding and dehydration risks. At 0.3 A/cm2, flooding occured when the uniformity index exceeded 125 mA/cm2, while dehydration risk was observed when the index ranged from 30 to 125 mA/cm2. Stable startup was achieved when the uniformity index was below 30 mA/cm2. Case comparisons suggested that nitrogen purging at 70 % humidity (1200 ml/min for 2 min) and hydrogen–oxygen flow at 200 ml/min, with a 300-second delay at 0.2 A/cm2, ensured rapid and stable mode switching from EC to FC at 0.3 A/cm2. This work provides valuable insights into optimizing mode switching in UR-PEMFC systems and offers a reliable approach for enhancing their operational efficiency and stability. © 2025 Elsevier Ltd

关键词： Diffusion in solids

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Effects of process parameters on morphology and distribution of externally solidified crystals in microstructure of magnesium alloy die castings

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China Foundry 2018年第2期15卷 139-144页

作者： Meng-wu Wu Xiao-bo Li Zhi-peng Guo Shou-mei Xiong Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of Technology School of Materials Science and Engineering Tsinghua University

During the cold-chamber high pressure die casting(HPDC) process, samples were produced to investigate the microstructure characteristics of AM60B magnesium alloy. Special attention was paid to the effects of process parameters on the morphology and distribution of externally solidified crystals(ESCs) in the microstructure of magnesium alloy die castings, such as slow shot phase plunger velocity, delay time of pouring and fast shot phase plunger velocity. On the basis of metallographic observation and quantitative statistics, it is concluded that a lower slow shot phase plunger velocity and a longer delay time of pouring both lead to an increment of the size and percentage of the ESCs, due to the fact that a longer holding time of the melt in the shot sleeve will cause a more severe loss of the superheat. The impingement of the melt flow on the ESCs is more intensive with a higher fast shot phase plunger velocity, in such case the ESCs reveal a more granular and roundish morphology and are dispersed throughout the cross section of the castings. Based on analysis of the filling and solidification processes of the melt during the HPDC process, reasonable explanations were proposed in terms of the nucleation, growth, remelting and fragmentation of the ESCs to interpret the effects of process parameters on the morphology and distribution of the ESCs in the microstructure of magnesium alloy die castings.

关键词： magnesium alloy high pressure die casting microstructure externally solidified crystals process parameters

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Simplified Method of Simulating Double-Layer Micro-Perforated Panel Structure

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Automotive Innovation 2018年第4期1卷 374-380页

作者： Wan Chen Chihua Lu Zhien Liu Songze Du Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan University of TechnologyWuhan 430070China

The micro-perforated panel(MPP)structure has been widely used in various noise control applications,and thus its acoustic performance prediction has been receiving increasing *** acoustic performance of simple MPP structures,such as a MPPsound absorber,has been predicted using an analytical calculation ***,this is not a suitable approach toward predicting the acoustic performance of complicated MPP structures,owing to the structural complexity of these ***,the many perforations of submillimeter scale diameter render the MPP structures very difficult to analyze using numerical ***,this study focused on two different simplified MPP simulation methods:the transfer admittance method and the equivalent fluid method,and their application on double-layer MPP *** on the two simplified MPP simulation methods,the transmission loss value of the double-layer MPP mufflers with two sets of different structural parameters was calculated,*** predicted results were compared with the impedance tube *** results revealed that the two simplified MPP simulation methods could effectively predict the acoustic performance of doublelayer MPP ***,the prediction based on the transfer admittance method can outperform the two simplified simulation methods.

关键词： Double-layer MPP structure Acoustic simulation Transfer admittance Porous material Experimental test

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