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Review of Lagrangian stochastic models for turbulent combustion

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Acta Mechanica Sinica 2021年第10期37卷 1467-1488,I0001页

作者： Tianwei Yang Yu Yin Hua Zhou Zhuyin Ren School of Aerospace engineering Tsinghua UniversityBeijing100084China institute for Aero engine Tsinghua UniversityBeijing100084China

Predictive simulation of the combustion process in engine is crucial to understand the complex underlying physicochemical processes, improve engine performance, and reduce pollutant emissions. Key issues such as the physical modeling of the interaction between turbulence, chemistry and droplets, and the incorporation of the detailed chemistry in high-fidelity simulations of complex flows remain essential though challenging. This paper reviews the transported probability density function method for turbulent dilute spray flames in the dual-Lagrangian framework that shows potential to address some critical modeling issues. An overview is presented for the contributions made within the last decade or so for the three key ingredients for modeling the interaction between turbulence, chemistry and droplets, i.e., micro-mixing, subgrid dispersion and two-phase coupling. Then, various methods for detailed chemistry acceleration are reviewed to address the issue of high computational cost for its use in multidimensional simulations. Finally, some applications of the dual-Lagrangian method in both laboratory-scale and device-scale configurations are provided to demonstrate its capability as well as deficiency at the current stage. Some open modeling challenges are raised and recommended for further investigation.

关键词： Transported probability density function method Large eddy simulation Dual-Lagrangian framework Turbulent spray flames Detailed chemistry

Development of port fuel injected methanol(M85)-fuelled two-wheeler for sustainable transport

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Journal of Traffic and Transportation engineering(English Edition) 2020年第3期7卷 298-311页

作者： Tushar Agarwal Akhilendra Pratap Singh Avinash Kumar Agarwal engine R esearch Laboratory Department of Mechanical EngineeringIndian Institute of Technology KanpurKanpur 208016India

Due to increasingly stringent environmental pollution norms,there is a need for alternate combustion techniques and alternate fuels to keep up with changing *** of the viable solutions for India is the adaptation of methanol as a fuel for automotive ***,in this study a functional two-wheeler prototype was developed,which uses M85(85%v/v methanol and 15%v/v gasoline)in an electronic control unit(ECU)controlled port fuel injected(PFI)*** study included comparative investigations of simulated on-road two-wheeler performance on chassis dynamometer using a gasoline-fuelled motorcycle with stock ECU vis-a-vis M85-fuelled motorcycle using recalibrated *** recalibration exhibited that M85-fuelled vehicle was operated at relatively more advanced spark timing compared to baseline gasoline-fuelled *** results showed that M85-fuelled motorcycle produced relatively higher engine power and higher maximum vehicle speed compared to gasoline-fuelled *** superior acceleration characteristics(especially at higher speeds)of M85-fuelled motorcycle was another important finding of this study,indicating that M85 provided superior throttle response compared to *** analysis of raw tailpipe emissions showed that modified M85-fuelled motorcycle emitted relatively higher hydrocarbon(HC),carbon monoxide(CO)and oxides of nitrogen(NO_x)emissions compared to stock gasoline-fuelled ***,these emissions can be controlled by using adaptation of suitable after-treatment systems.

关键词： Methanol Electronic control unit(ECU) Electronic fuel injection(EFI) ECU calibration engine performance Emission

Analysis of dynamic stress intensity factors of thick-walled cylinder under internal impulsive pressure

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Acta Mechanica Sinica 2009年第6期25卷 803-809页

作者： Aijun Chen Lianfang Liao Dingguo Zhang School of Sciences Nanjing University of Scienceand Technology 210094 Nanjing China Shenyang Aero-engine Research institute 110015 Shenyang China

Dynamic stress intensity factors are evaluated for thick-walled cylinder with a radial edge crack under internal impulsive pressure. Firstly, the equation for stress intensity factors under static uniform pressure is used as the reference case, and then the weight function for a thick-walled cylinder containing a radial edge crack can be worked out. Secondly, the dynamic stresses in uncracked thick-walled cylinders are solved under internal impulsive pressure by using mode shape function method. The solution consists of a quasi-static solution satisfying inhomogeneous boundary conditions and a dynamic solution satisfying homogeneous boundary condi- tions, and the history and distribution of dynamic stresses in thick-walled cylinders are derived in terms of Fourier-Bessel series. Finally, the dynamic stress intensity factor equations for thick-walled cylinder containing a radial edge crack sub- jected to internal impulsive pressure are given by dynamic weight function method. The finite element method is utilized to verify the results of numerical examples, showing the validity and feasibility of the proposed method.

关键词： Thick-walled cylinder . Cracks .Dynamic stress intensity factors . Weight function methodMode shape function

Experiments of flow and heat transfer performances for air-cooling laminated turbine vane

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航空动力学报 2014年第5期29卷 1008-1013页

作者： WU Xiang-yu TAO Zhi DU Zhi-neng ZHANG Shu-lin YOU Hong-de National Key Laboratory of Science and Technology on Aero-engine Aero-thermodynamics School of Energy and Power Engineering Beijing University of Aeronautics and Astronautics Beijing 100191 China Shenyang engine Design and Research institute Aviation Industry Corporation of China Shenyang 110015 China

Flow resistance and heat transfer coefficients of typical double wall laminated film cooling configuration within a turbine vane were experimentally *** specimen was in large scale,and made of transparent organic *** configuration consisted of double wall laminates,pin-fins,staggered arrays of impingement and film *** number ratio of impingement holes,pin-fins and film holes was2∶1∶*** experiment vanes were installed in static cascade,and experiments were carried out under constant heat *** of internal cooling air in the experiment was from 104 to 2×105,and Re of external fluid was from 105 to 3×*** experiment results show that flow resistances of front channel and back channel of the vane are in the same level,and both of them decrease as Re of cooling air *** front channel is slightly higher than that of back *** of them increase as Re of cooling air *** experiment results were obtained from experiment vanes were compared with that obtained from laminated flat plates,and the tendency of the results agrees well.

关键词：层板涡轮叶片流动性能传热静叶栅

STUDY ON BURNING PURE METHANOL IN SPARK IGNITION engineS

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Progress in Natural Science:Materials International 1992年第2期 157-163页

作者：傅茂林史绍熙张荣寿刘建新贺师德何国平 Beijing 100026 Beijing Automotive Research institute National engine combustion Laboratory Tianjin University PRC Tianjin 300072

This paper reports the results of an experimental study of burning pure methanol in a gasoline engineby modifying the structure of the combustion chamber,increasing the compression ratio and changing thethroat area of the carburetor *** results show that the engine gives smooth operationand satisfactory *** power output and torque reach the same levels as those of the origi-nal gasoline *** specific fuel consumption by weight throughout the engine speed range at full throt-tle is 51%—69% higher due to the lower heating value of ***,the highest brake thermalefficiency is 32.7% higher than that of the original gasoline engine.

关键词： spark ignition engine pure methanol combustion thermal efficiency

Application of immersed boundary method in turbomachines

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Chinese Journal of Aeronautics 2023年第5期36卷 268-279页

作者： Congcong CHEN Yuwei WANG Zhuo WANG Lin DU Xiaofeng SUN School of Energy and Power engineering Beihang UniversityBeijing 100191China Research institute of Aero-engine Beihang UniversityBeijing 100191China

Simulating unsteady turbulent flow in turbomachines is still challenging due to the complexity of blade geometry and relative motion between rotor and *** study presents an Immersed Boundary Method(IBM)for high-Reynolds turbomachinery internal flows,and shows the advantage of the automatic grid generation techniques and flexible moving boundary *** wall functions are used in the present method to alleviate the wall resolution restriction of turbulence *** Two-Dimensional(2-D)IBM solver,which was previously developed and tested for a low-speed compressor,is further validated for a well-documented Low-Pressure Turbine(LPT)*** the blade loading and the total pressure losses in the wake are well captured by the present 2-D *** complex Three-Dimensional(3-D)effects in turbomachines motivate the further development of an extended 3-D IBM solver by using a curvilinear-coordinate system that facilitates the hub and casing boundary *** good performance of the 3-D solver is demonstrated through comparison with CFX solver solutions for the rotor configuration of Advanced Noise Control Fan(ANCF).Further effects of the grid resolution on capturing the blade wake are *** results indicate that the present 3-D solver is capable of reproducing the evolution of the blade wake with suitable computational grid.

关键词： Immersed boundary method Turbomachinery Turbulence simulation Wake prediction Wall function

General Technical Specifications and Test Methods of Small and Medium Power internal combustion engine

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China Standardization 2011年第2期56卷 39-43页

作者： Xie Yaping Ji Weibin Qu Junming Sun Shaojun Zhuang Guogang Zhang Chaojian Li Shusheng Tan Zhimin Xie Zhengliang Luo Jinxing State internal combustion engine Standardization Technical Committee (SAC/TC177) Standard Office of Shanghai internal combustion engine Research institute

Project Name： GB/T 1147.1-2007 Small and Medium Power lnternal combustion engines--Part 1.＂ General Requirements and GB/T 1147.2-2007 Small and Medium Power internal combustion engines--Part 2： Test Methods

关键词：中小功率试验方法内燃机技术项目名称城市生活

Theoretical model of azimuthal combustion instability subject to non-trivial boundary conditions

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Chinese Journal of Aeronautics 2024年第9期37卷 113-130页

作者： Lei QIN Xiaoyu WANG Guangyu ZHANG Xiaofeng SUN Research institute of Aero-engine Beihang UniversityBeijing 100191China School of Energy and Power engineering Beihang UniversityBeijing 100191China

The problem of evaluating the sensitivity of non-trivial boundary conditions to the onset of azimuthal combustion instability is a longstanding challenge in the development process of modern gas *** difficulty lies in how to describe three-dimensional in-and outlet boundary conditions in an artificial computational *** date,the existing analytical models have still failed to quantitatively explain why the features of the azimuthal combustion instability of a combustor in laboratory environment are quite different from that in a real gas turbine,making the stability control devices developed in laboratory generally lose the effectiveness in practical *** overcome this limitation,we provide a novel theoretical framework to directly include the effect of non-trivial boundary conditions on the azimuthal combustion instability.A key step is to take the non-trivial boundary conditions as equivalent distributed sources so as to uniformly describe the physical characteristics of the inner surface in an annular enclosure along with different in-and outlet ***,a dispersion relation equation is established by the application of three-dimensional Green's function approach and generalized impedance *** show that the effects of the generalized modal reflection coefficients on azimuthal unstable modes are extremely prominent,and even prompt the transition from stable to unstable mode,thus reasonably explaining why the thermoacoustic instability phenomena in a real gas turbine are difficult to observe in an isolated combustion ***,this work provides an effective tool for analysis of the azimuthal combustion instability including various complicated boundary conditions.

关键词： combustion instability Aeroacoustics Modeling Optimization techniques Control

Measurements of Water-Air Flow Phenomena in a Chamber with a Rotating Shaft

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Journal of Thermal Science 2021年第1期30卷 242-247页

作者： TIUTIURSKI Paweł HERCEL Paulina TELEGA Janusz KARDAŚDariusz Flow and combustion Department Renewable Energy FacultyInstitute of Fluid Flow Machinery Polish Academy of SciencesFiszera 1480-231GdańskPoland Flow and combustion Department Experimental Aerodynamics FacultyInstitute of Fluid Flow Machinery Polish Academy of SciencesFiszera 1480-231GdańskPoland

The paper concerns the phenomena of the fluid film that occurs in the bearing chamber of an aircraft *** geometry of the system includes two concentric cylinders,between which there is a mixture of oil and *** fluid circulates in a closed *** rotary movement of the inner cylinder causes creation of the fluid film on the walls of the *** article proposes a measurement method that is allowing observation of this fluid film and,in particular,analysis of the movement of the air bubbles occurring in the *** own model of the bearing chamber with transparent walls was constructed for the *** the investigation,water was used instead of *** of the behaviour of the flow was possible thanks to video recordings made with the use of a fast-capture *** results presented in the paper include velocity magnitudes of the air bubbles in the fluid film in dependence on the rotational speed of the shaft and water volume fraction and with a range from 0.37 to 0.91 m/*** results presented in this article can be used for the bearing chamber numerical models validation.

关键词： bearing chamber measurements fluid film velocity two-phase flow