检索结果-内蒙古大学图书馆

Experimental and numerical investigations of the aerodynamic noise reduction of automotive side view mirrors

Journal of Hydrodynamics 2018年第4期30卷 642-650页

作者：陈鑫汪硕吴元强李延洋王怀玉 State Key Laboratory of Automobile Simulation and Control Jilin University

This paper studies the aeroacoustics of the side view mirrors by wind tunnel tests and numerical simulations. The mirror is placed on a table in the wind tunnel test. Based on the experiment results, a numerical analysis model is established to analyze the acoustic field in the wake of the side view mirror by the Large Eddy simulation（LES）. The flow field and the noise level of two different side view mirrors are compared in the simulation. It is shown that, with the serration structures applied onto the mirror surface, the turbulence zone and the pressure fluctuation in the wake of the bionic model are improved effectively, which helps its flow control and noise reduction. Meanwhile, as is shown in the noise spectra, when the noise frequency is over 500 Hz, for the bionic mode, the noise is reduced to a lower level than with the original one, which further shows its effectiveness in the noise reduction.

关键词： Aerodynamic noise side view mirror flow field acoustic field bionic noise reduction

来源：评论

学校读者我要写书评

暂无评论

Novel Evaluation Method of Vehicle Suspension Performance Based on Concept of Wheel Turn Center

引用

Chinese Journal of Mechanical Engineering 2015年第5期28卷 935-944页

作者： WANG Bo GUAN Hsin LU Pingping ZHAN Jun State Key Laboratory of Automobile Simulation and Control Jilin University

The current research of suspension performance evaluation is mixed in the evaluation of vehicle handling and ride comfort. However, it is lack of a direct and independent evaluation method for suspension performance. In this paper, a novel wheel turn center method is proposed to evaluate the suspension performance. This method is based on the concept and application of wheel turn center （WTC） and sprung mass turn center （SPTC）. The vehicle body and each wheel are regarded to be independent rigid bodies and have their own turn centers which reflect respective steering motions and responses. Since the suspension is the link between vehicle body and wheels, the consistence between the sprung mass turn center and the wheel turn center reflects the effect and performance of the suspension system. Firstly, the concept and appropriate calculation method of WTC and SPTC are developed. Then the degree of inconsistence between WTC and SPTC and the time that they achieve consistence, when the vehicle experiences from transient steering to steady steering state, are proposed to evaluate suspension performance. The suspension evaluation tests are conducted under different vehicle velocities and lateral accelerations by using CarSim software. The simulation results show that the inconsistence of steering motion between vehicle body and wheels are mainly at high speeds and low lateral accelerations. Finally, based on the proposed evaluation indexes, the influences of different suspension characteristic parameters on suspension performance and their matches to improve steering coordination are discussed. The proposed wheel turn center method provides a guidance and potential application for suspension evaluation and optimization.

关键词： suspension evaluation wheel turn center sprung mass turn center

来源：评论

学校读者我要写书评

暂无评论

The mitigation efficacy and mechanism for H₂S and CH₄ emission from wastewater by adding bacterium-fungus mixture

引用

Journal of Water Process Engineering 2025年 75卷

作者： Qi, Zheng Jia, Tipei Cong, Wenjie Xi, Jinying Environmental Simulation and Pollution Control State Key Joint Laboratory School of Environment Tsinghua University Beijing 100084 China

Anaerobic conditions in wastewater systems produce H₂S and CH₄, leading to pipeline corrosion and environmental risks. While various chemical solutions have been proposed, they often suffer from secondary pollution. This study developed and optimized a microbial strategy to reduce H₂S and CH₄ emissions by simultaneously adding yeast and bacterial strain. Optimal results were obtained with a 1:2 ratio of Bacillus subtilis to Saccharomyces cerevisiae at 10⁷ CFU/mL, achieving reductions of 65.8 % for H₂S and 62.4 % for CH₄. The addition of bacterium-fungus mixture altered carbon and sulfur metabolic pathways, community structure, and functional gene abundance, which ultimately reduced H₂S and CH₄ emissions. Specifically, the increase in redox potential leads to the accumulation of other sulfur compounds such as S₂O₃²⁻. Additionally, elevated concentrations of long-chain fatty acids and decreased acetate concentrations limited the substrates required for CH₄ production. Community structure and metagenomic analyses confirmed these changes, showing reduced relative abundances of sulfate-reducing bacteria, methanogens, and associated functional genes, as well as increased genes abundance associated with organic sulfur synthesis and propionate/butyrate production. These findings demonstrate that addition of bacterium-fungus mixture can effectively modulate microbial community structure and metabolic pathways, offering a viable strategy for reducing H₂S and CH₄ emissions in wastewater. © 2025 Elsevier Ltd

关键词： Bacterium-fungus mixture Methane Wastewater, sulfide

来源：评论

学校读者我要写书评

暂无评论

Numerical simulation of the aerodynamic characteristics of heavy-duty trucks through viaduct in crosswind

引用

Journal of Hydrodynamics 2014年第3期26卷 394-399页

作者：胡兴军秦鹏廖磊郭鹏王靖宇杨博 State Key Laboratory of Automobile Simulation and Control Jilin University

In our numerical simulation the hybrid mesh and the SST k-ω turbulence model are adopted to investigate the variations of the aerodynamic loads and the flow field of heavy-duty trucks while crossing a viaduct with 1.1 m high fences in a crosswind at a velocity of 20 m/s. The results show that, with the protection of a fence, the side force is weakened, and the rolling and yaw moments are strengthened while the truck is crossing the viaduct, which relatively reduces the roll-over safety and the driving stability of the truck. Meanwhile, the direction of the side force changes when the truck enters the viaduct, which makes the roll-over safety and the driving stability the lowest during the process.

关键词： computational fluid dynamics heavy-duty truck crosswind cross viaduct aerodynamic loads flow field

来源：评论

学校读者我要写书评

暂无评论

Corrigendum to "Landscape ecological risk assessment and driving factors analysis based on optimal spatial scales in Luan River Basin, China" [Ecol. Indic. 169 (2024) 112821] (Ecological Indicators (2024) 169, (S1470160X24012780), (10.1016/***.2024.112821))

引用

Ecological Indicators 2025年 173卷

作者： Yang, Nijuan Zhang, Ting Li, Jianzhu Feng, Ping Yang, Nina State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation Tianjin University Tianjin300350 China State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Tsinghua University Beijing100084 China

The authors regret "the incorrect use of Figure 1 in the paper. The original figure has now been replaced with the revised figure."[Figure presented] Revised Figure 1 The authors would like to apologise for ...

关键词：

来源：评论

学校读者我要写书评

暂无评论

An Optimal Competitive Bidding and Pricing Strategy for Electric Vehicle Aggregator Considering the Bounded Rationality of Users

引用

IEEE Transactions on Industry Applications 2025年第3期61卷 4898-4912页

作者： Wang, Qi Huang, Chunyi Wang, Chengmin Xie, Ning Li, Kangping Qiu, Peng Shanghai Jiao Tong University School of Electronic Information and Electrical Engineering Shanghai200240 China Northeast Electric Power University Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Ministry of Education Jilin132012 China Shanghai Jiao Tong University College of Smart Energy Shanghai200240 China State Grid Zhejiang Electric Power Company Electric Power Research Institute Hangzhou310014 China

Accurate estimation of the charging demand of electric vehicle (EV) users has a profound impact on the profitability of the EV aggregator (EVA). Existing studies concerning the market strategy of EVA normally assume the EV users are equipped with complete rationality and simplify the real interactive process among EVAs and EV users, making the derived strategy unable to adapt to the practical situations. To address this bottleneck, a novel competitive bidding and pricing strategy for EVA considering both the bounded rationality of EV users and various game relationships between multiple agents is proposed. Firstly, the evolutionary game theory is utilized to simulate the bounded rational charging behaviors of EV users under differentiated charging prices, while their demand elasticity and uncertainty of driving pattern is also taken into account. Secondly, the complex interactions among EVAs and EV users are modeled, where the competition between EVAs is constructed by a non-cooperative game with incomplete information and the interplay between EVAs and EV users is built as a Stackelberg game. Finally, numerical results validate the effectiveness of the proposed method and demonstrate the pricing strategy preferences of EVAs based on the diverse price elastic coefficients of EV users. © 2025 IEEE. All rights reserved

关键词： Game theory

来源：评论

学校读者我要写书评

暂无评论

Ecological Mechanisms of Carbon Sequestration in Vegetated Coastal Wetland Ecosystem: Exploring the Roles of Biodiversity and Environmental Changes

引用

Journal of Marine Environmental Engineering 2025年第1期12卷 35-47页

作者： Liu, Lele Du, Ning Eller, Franziska Ye, Siyuan Li, Xiaowen Wei, Jifang Guo, Yaolin Brix, Hans Guo, Weihua Key Laboratory of Ecological Prewarning Protection and Restoration of Bohai Sea Ministry of Natural Resources School of Life Sciences Shandong University 72 Binhai Road Qingdao266237 China Department of Biology Aarhus University Ole Worms Alle 1 Aarhus8000 Denmark Key Laboratory of Coastal Wetland Biogeosciences Qingdao Institute of Marine Geology China Geological Survey Qingdao266000 China School of Environment State Key Joint Laboratory of Environment Simulation and Pollution Control Beijing Normal University Beijing100875 China North China Sea Ecological Center of the Ministry of Natural Resources Qingdao266000 China Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary Institute of Biodiversity Science and Institute of EcoChongming School of Life Sciences Fudan University Shanghai200433 China

Vegetated coastal wetlands, also called blue carbon ecosystems, are significant carbon sinks that play a vital role in global climate change mitigation. Understanding the ecological mechanisms of carbon sequestration in these ecosystems is essential to effectively manage and conserve them. This review focuses on macroecological mechanisms of carbon transfer and microecological mechanisms of carbon stabilization in vegetated coastal wetland ecosystems. Macroecological mechanisms include the horizontal and vertical carbon transport coupled to plant ecophysiology and community diversity, while microecological mechanisms include processes related to soil organic matter dynamics, such as decomposition, stabilization, and mineralization. key scientific issues surrounding these mechanisms include transformation between carbon sink and source, stabilization mechanisms of organic carbon, and environmental effects at multiple time scales. A comprehensive research framework is also presented, which integrates spatial-temporal pattern, macroecological mechanism, microecological mechanism, and ecological engineering. Addressing these key scientific questions within the proposed framework can provide valuable insights into the significant role of biodiversity in blue carbon ecosystems, as well as significant implications for management and conservation of vegetated coastal wetlands under global climate changes. © 2025 Old City Publishing, Inc.

关键词： Ecosystems

来源：评论

学校读者我要写书评

暂无评论

Suppression of Phase Current Ripple and Torque Harmonics in Four-Module PMSM with Asymmetric Mutual Inductance

引用

IEEE Transactions on Power Electronics 2025年

作者： Liu, Kaiyuan Li, Chi Zheng, Zedong Li, Yongdong Tsinghua University State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Beijing100084 China

In N-module motors, uniform carrier phase shifting (UCPS) by 2π/N between modules can effectively suppress torque harmonics caused by high-frequency switching of power devices. In multi-module motors with fractional-slot concentrated winding, the mutual inductance between adjacent windings is higher than that between non-adjacent windings. Although the conventional UCPS can reduce the torque sideband harmonics synthesized by the four modules, this asymmetric mutual inductance (AMI) paradoxically increases phase current ripple in each sub-module, leading to higher system losses. Aiming at this problem, this paper derives the mathematical model of N-module motor with AMI, analyzes the limitations of the traditional UCPS method that increases the phase current ripple. For different optimization objectives, two carrier phaseshifting angle optimized strategies are proposed to achieve integrated suppression of torque sideband harmonics and intramodule phase current ripples, with a genetic algorithm improving optimization speed. A threshold coefficient is introduced to achieve a tradeoff between phase current ripple and q-axis current harmonics, which can be adjusted to prioritize objectives based on user requirements. To enhance algorithm adaptability, the paper further investigates model variations under uneven torque distribution in sub-healthy states and proposes an improved comprehensive optimization algorithm, limiting torque sideband harmonics and current ripple in both healthy and sub-healthy conditions. Finally, the proposed algorithm is validated experimentally by a four-module permanent magnet synchronous motor. © 2025 IEEE.

关键词： Genetic algorithms

来源：评论

学校读者我要写书评

暂无评论

Investigation of the combustion deterioration of an automotive diesel engine under transient operation

引用

Science China(Technological Sciences) 2014年第3期57卷 480-488页

作者： ZHANG LongPing LIU ZhongChang TIAN Jing SUN ShiJie State Key Laboratory of Automobile Simulation and Control Jilin University

With increasingly stringent emission regulations and demand for fuel economy by the public,the combustion and emission problems of automotive diesel engines during transient operation have become vital and urgent *** this study,combustion deterioration has been experimentally analyzed using a heavy-duty turbocharged diesel engine running under transient conditions(constant speed and increasing torque).Optimization of the transient combustion process was performed by adjusting the fuel injection *** results indicated that the notable combustion deterioration relative to steady state operation while transient was a function of the delay in the air-supply to the turbocharged engine,and took the form of combustion phasing delay,resulting in rapidly increasing smoke emission and fuel ***,the delay in combustion phasing can be controlled by advancing the fuel injection timing,effectively increasing thermal ***,smoke and NO x emissions increased at the same *** deterioration in combustion phasing can also be improved by increasing injection pressure,resulting in decreased smoke emission while NO x emission *** is worth noting that the effective thermal efficiency first increased and then decreased as fuel injection pressure increased during transient operation.

关键词： diesel engine transient operation combustion deterioration injection parameters combustion optimization

来源：评论

学校读者我要写书评

暂无评论

Ultrahigh alkali resistance and regeneration capacity of the birnessite deNOx catalysts: A recyclable extraction-insertion strategy

引用

Separation and Purification Technology 2025年 368卷

作者： Xuan, Yue Zhu, Xiao Wang, Bin Liang, Yanjie Gao, Chuan Li, Bing Wang, Dong Peng, Yue School of Energy and Power Engineering Shandong University Shandong Jinan250061 China State Key Joint Laboratory of Environment Simulation and Pollution Control National Engineering Laboratory for Multi Flue Gas Pollution Control Technology and Equipment School of Environment Tsinghua University Beijing100084 China

The selective catalytic reduction (SCR) of NOx with NH3 in biomass combustion flue gas confronts high-concentration alkali metal (K) poisoning. Herein, we propose a recyclable extraction-insertion strategy using acid-treated birnessite-based catalysts to achieve high alkali resistance. Compared to commercial MnO2 catalyst, which suffered severe deactivation after 1 wt% K+ poisoning, the OL-1(H) catalyst showed a surprising enhancement in SCR activity by 1 wt% K+ and only a modest 15.5 % decrease in NOx conversion at 225 °C with 7 wt% K+. Physicochemical characterizations and density functional theory calculations revealed that K+ deposition form K2O on the surface of commercial MnO2, disrupting Mn-O active sites. In contrast, K+ tended to migrate from the outer surface into the interlayer, spontaneously exchanging with H+ in the OL-1(H) catalyst. The inserted K+ coordinated with six O2–, attracting surrounding electron clouds and facilitating electron loss from Mn species with unsaturated outer coordination. This resulted in an enrichment of Mn5c4+-Lewis acid sites, enhancing NH3 adsorption and activation, thereby improving NOx removal via the Eley-Rideal (E-R) mechanism. Equally important, the extraction-insertion process between H+ and K+ further regenerated the K-poisoned catalyst efficiently, restoring the NOx conversion by 23.3 % at 150 °C. The recyclable extraction-insertion strategy provides a new paradigm for designing catalysts with ultrahigh alkali resistance and regeneration capacity, applicable across various environmental fields. © 2025

关键词： Nitrogen oxides

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：