检索结果-南通市图书馆

A dual timescale model for micro-mixing and its application in LES-TPDF simulations of turbulent nonpremixed flames

Chinese Journal of aeronautics 2019年第4期32卷 875-887页

作者： Fang WANG Rui LIU Li DOU Denghuan LIU Jie JIN aero-engine numerical simulation research center School of Energy and Power EngineeringBeihang University Collaborative Innovation center for Advanced aero-engine

The numerical simulation of modern aero-engine combustion chamber needs accurate description of the interaction between turbulence and chemical reaction mechanism. The Large Eddy simulation(LES) method with the Transported Probability Density Function(TPDF) turbulence combustion model is promising in engineering applications. In flame region, the impact of chemical reaction should be considered in TPDF molecular mixing model. Based on pioneer research, three new TPDF turbulence-chemistry dual time scale molecular mixing models were proposed tentatively by adding the chemistry time scale in molecular mixing model for nonpremixed flame. The aero-engine Combustor simulation Code(AECSC) which is based on LES-TPDF method was combined with the three new models. Then the Sandia laboratory's methane-air jet flames: Flame D and Flame E were simulated. Transient simulation results show that all the three new models can predict the instantaneous combustion flow pattern of the jet flames. Furthermore,the average scalar statistical results were compared with the experimental data. The simulation result of the new TPDF arithmetic mean modification model is the closest to the experimental data:the average error in Flame D is 7.6% and 6.6% in Flame E. The extinction and re-ignition phenomena of the jet flames especially Flame E were captured. The turbulence time scale and the chemistry time scale are in different order in the whole flow field. The dual time scale TPDF combustion model has ability to deal with both the turbulence effect and the chemistry reaction effect, as well as their interaction more accurately for nonpremixed flames.

关键词： Dual time scale model Large eddy simulation Sandia methane-air jet flame TPDF molecular mixing model Turbulence combustion model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Thick exchange layer evaporation model with natural convection effect and evaporation experimental study for multicomponent droplet

引用

Chinese Journal of aeronautics 2020年第7期33卷 1903-1918页

作者： Fang WANG Xiang GAO Yangchun XIAO Zhaoyang WU Jie JIN aero-engine numerical simulation research center School of Energy and Power EngineeringBeihang UniversityBeijing 100083China

In order to investigate the high-temperature evaporation characteristics of multicomponent liquid fuel,three kinds of blended fuel:n-heptane/n-decane/RP-3 aviation kerosene-ethanol were experimentally studied with and without forced ***,based on zerodiffusion and infinite diffusion concept,this study expanded Thick Exchange Layer evaporation model with Natural Convection effect(NC-TEL)to multicomponent liquid *** experimental results show that the droplet evaporation rate increases significantly with the increase of ambient *** temperature leads to more significant relationships between the composition ratio and the evaporation *** effect of forced convection is not obviously under the circumstance in this ***,the evaporation models were validated by experimental *** general,the new NC-TEL model behaves better than the Ranz-Marshall(R-M)model,and the prediction accuracy at high temperature is improved by 8%to 35%.In lower temperature conditions,the prediction of zero-diffusion NC-TEL model is better than the infinite diffusion NC-TEL *** high-temperature conditions,for n-heptane-ethanol droplet,the predictions of NC-TEL model are accurate,but for n-decane/RP-3 aviation kerosene-ethanol,the predictions are lower than experimental *** may be caused by the micro-explosion phenomenon and the Marangoni phenomenon.

关键词： Droplet Evaporation rate Multicomponent fuel evaporation model Natural convection Suspended droplet experiment Thick exchange layer model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A new stationary droplet evaporation model and its validation

引用

Chinese Journal of aeronautics 2017年第4期30卷 1407-1416页

作者： Fang WANG Jie YAO Shaofeng YANG Rui LIU Jie JIN aero-engine numerical simulation research center School of Energy and Power Engineering Beihang University Beijing100083 China Co-Innovation center for Advanced aero-engine Beijing 100083 China

The liquid droplet evaporation character is important for not only combustion chamber design process but also high-accuracy spray combustion simulation. In this paper, the suspended droplets＇ evaporation character was measured in a quiescent high-temperature environment by micro high-speed camera system. The gasoline and kerosene experimental results are consistent with the reference data. Methanol, common kerosene and aviation kerosene droplet evaporation characteristics, as well as their evaporation rate changing with temperature, were obtained. The evaporation rate experimental data were compared with the prediction result of Ranz-Marshall boiling temperature model（RMB）, Ranz-Marshall low-temperature model（RML）, drift flux model（DFM）, mass analogy model（MAM）, and stagnant film model（SFM）. The disparity between the experimental data and the model prediction results was mainly caused by the neglect of the natural convection effect, which was never introduced into the droplet evaporation concept. A new droplet evaporation model with consideration of natural convection buoyancy force effect was proposed in this paper. Under the experimental conditions in this paper, the calculation results of the new droplet evaporation model were agreed with the experimental data for kerosene, methanol and other fuels, with less than 20% relative deviations. The relative deviations between the new evaporation model predictions for kerosene and the experimental data from the references were within 10%.

关键词： Droplet Evaporation model Evaporation rate Kerosene Natural convection Thick exchange layer theory

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of turbulence on NO formation in swirling combustion

引用

Chinese Journal of aeronautics 2014年第4期27卷 797-804页

作者： Wang Fang Xie Xiang Jiang Qi Zhou Lixing aero-engine numerical simulation research center School of Energy and Power Engineering Beihang University Department of engineering Mechanics Tsinghua University

Turbulence affects both combustion and NO formation. Fluctuation correlations are ideally used for quantitative analysis. From the instantaneous chemical reaction rate expression,ignoring the third-order correlation terms, the averaged reaction rate will have four terms, including the term of averaged-variable product, a concentration fluctuation correlation term, and temperature-concentration fluctuation correlation term. If the reaction-rate coefficient is denoted as K, the temperature fluctuation would be included in the K fluctuation. In order to quantitatively study the effect of turbulence on NO formation in methane-air swirling combustion, various turbulencechemistry models are tested. The magnitudes of various correlations and their effects on the time-averaged reaction rate are calculated and analyzed, and the simulation results are compared with the experimental measurement data. The results show that among various correlation moments, the correlation between the reaction-rate coefficient K fluctuation with the concentration fluctuation is most important and is a strong nonlinear term.

关键词： NO formation numerical simulation Reaction-rate coefficient Second-order moment model Turbulent combustion model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of Inlet Circumferential Fluctuation on the Sweep aerodynamic Performance of Axial Fans/Compressors

引用

Journal of Thermal Science 2013年第5期22卷 383-394页

作者： Xingmin Gui Fang Zhu Ke Wan Donghai Jin aero-engine simulation research center Beijing University of Aeronautics and Astronautics

Swept blades have been widely used in the transonic fan/compressor of aircraft engines with the aids of 3D CFD simulation since the design concept of controlling the shock structure was firstly proposed and successfully tested by *** in the ***,some disadvantage phenomenon has also been induced by excessively 3D blade geometries on the structure stress insufficiency,vibration and *** confusion in the procedure of design practice leading us to recognize a new view on the flow mechanism of sweep aerodynamical induction: the new radial equilibrium established by the influence of inlet circumferential fluctuation(CF) changes the inlet flows of blading and induces the performance modification of axial fans/compressors *** view is verified by simplified models through numerical simulation and circumferentially averaged analysis in the present *** results show that the CF source items which originate from design parameters,such as the spanwise distributions of the loading and blading geometries,contribute to the changing of averaged incidence spanwise distribution,and further more affect the performance of axial fans/compressors with swept blades.

关键词： turbomachinery fans/compressors sweep aerodynamics quasi-3D method 3D flow

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

numerical Investigation of Base-Setting of Stator's Stagger Angles for a 15-stage Axial-Flow Compressor

引用

Journal of Thermal Science 2014年第1期23卷 36-44页

作者： CHANG Hao ZHAO Weiguang JIN Donghai PENG Zeyan GUI Xingmin aero-engine simulation research center School of Energy and Power EngineeringBeihang University 37

A 15-stage axial-flow compressor utilized in steel industry was studied in this paper. All the stator's stagger angles of the compressor are variable to ensure the multistage compressor operate effectively within a wide range of flow rate and meanwhile satisfy the demand for sufficient pressure ratio, adiabatic efficiency and stall margin. Three in all different base-settings of stator's stagger angles were presented and commercial CFD software was applied to obtain the overall performance characteristics. The results showed that both of the optimized base-settings improved the performances both in summer and winter conditions, although the adiabatic efficiency was somewhat decreased. Taking incidence angle and stage loading into consideration, differences among the three cases were analyzed in detail. On the basis of numerical computations, the performance could be effectively improved through adjusting the base-setting of stator's stagger angles.

关键词： multistage compressor stagger angle incidence angle variable stator

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A novel multi-fidelity coupled simulation method for flow systems

引用

Chinese Journal of aeronautics 2013年第4期26卷 868-875页

作者： Wang Peng Zheng Yun Zou Zhengping Qi Lei Zhou Zhixiang National Key Laboratory of Science & Technology on aero-engine aero-thermodynamics School of Energy and Power Engineering Beihang University aeroengine numerical simulation research center School of Energy and Power Engineering Beihang University Chinese Aviation Powerplant research Institute

For the numerical simulation of flow systems with various complex components, the traditional one-dimensional （1D） network method has its comparative advantage in time consuming and the CFD method has its absolute advantage in the detailed flow capturing. The proper coupling of the advantages of different dimensional methods can strike balance well between time cost and accuracy and then significantly decrease the whole design cycle for the flow systems in modern machines. A novel multi-fidelity coupled simulation method with numerical zooming is developed for flow systems. This method focuses on the integration of one-, two-and three-dimensional codes for various components. Coupled iterative process for the different dimensional simulation cycles of sub-systems is performed until the concerned flow variables of the whole system achieve convergence. numerical zooming is employed to update boundary data of components with different dimen-sionalities. Based on this method, a highly automatic, multi-discipline computing environment with integrated zooming is developed. The numerical results of Y-Junction and the air system of a jet engine are presented to verify the solution method. They indicate that this type of multi-fidelity simulationmethod can greatly improve the prediction capability for the flow systems.

关键词： Complex flow system Coupling Jet engine Multi-fidelity Zooming

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Corner Flow Control in High Through-Flow Axial Commercial Fan/Booster Using Blade 3-D Optimization

引用

Journal of Thermal Science 2012年第1期21卷 32-41页

作者： Fang Zhu Donghai Jin Xingmin Gui aeroengine numerical simulation research center Beihang University Beijing China

This study is aimed at using blade 3-D optimization to control corner flows in the high through-flow fan/booster of a high bypass ratio commercial turbofan engine. Two kinds of blade 3-D optimization, end-bending and bow, are focused on. On account of the respective operation mode and environment, the approach to 3-D aerodynamic modeling of rotor blades is different from stator vanes. Based on the understanding of the mechanism of the corner flow and the consideration of intensity problem for rotors, this paper uses a variety of blade 3-D optimization approaches, such as loading distribution optimization, perturbation of departure angles and stacking-axis manipulation, which are suitable for rotors and stators respectively. The obtained 3-D blades and vanes can improve the corner flow features by end-bending and bow effects. The results of this study show that flows in corners of the fan/booster, such as the fan hub region, the tip and hub of the vanes of the booster, are very complex and dominated by 3-D effects. The secondary flows there are found to have a strong detrimental effect on the compressor performance. The effects of both end-bending and bow can improve the flow separation in corners, but the specific ways they work and application scope are somewhat different. Redesigning the blades via blade 3-D optimization to control the corner flow has effectively reduced the loss generation and improved the stall margin by a large amount.

关键词： corner flow control fan/booster blade 3-D optimization end-bending bow

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influence of Non-Axisymmetric Terms on Circumferentially Averaged Method in Fan/Compressor

引用

Journal of Thermal Science 2013年第1期22卷 13-22页

作者： Ke Wan Hailiang Jin Donghai Jin Xingmin Gui aeroengine numerical simulation research center Beijing University of Aeronautics and Astronautics China Aviation Powerplant research Institute

The governing equations are derived by circumferentially averaging the three-dimensional （3D） Navier-Stokes equations, which are solved using a time marching finite volume approach. Both Euler throughflow model and Navier-Stokes （N-S） throughflow model are employed to investigate the performance and flow fields of a highly loaded transonic single-stage fan ATS-2 and a four-stage fan. The results are compared with the experimental and three-dimensional computational results. It shows that the throughflow models can provide reasonable perform- ance characteristics and N-S throughflow model gives better predictions in endwall regions. A throughflow com- putation in which all the non-axisymmetric terms are included has been performed at off-design condition and the radial distributions of the flow field can be well described.

关键词： throughflow model circumferentiaily averaged non-axisymmetric terms fan

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Two freedom linear parameter varying μ synthesis control for flight environment testbed

引用

Chinese Journal of aeronautics 2019年第5期32卷 1204-1214页

作者： Meiyin ZHU Xi WANG Zhihong DAN Song ZHANG Xitong PEI School of Energy and Power engineering Beihang University Collaborative Innovation center for Advanced aero-engine Science and Technology on Altitude simulation Laboratory

To solve the problem of robust servo performance of Flight Environment Testbed(FET)of Altitude Ground Test Facilities(AGTF) over the whole operational envelope, a two-degree-offreedom μ synthesis method based on Linear Parameter Varying(LPV) schematic is proposed, and meanwhile a new structure frame of μ synthesis control on two degrees of freedom with double integral and weighting functions is presented, which constitutes a core support part of the paper. Aimed at the problem of reference command's rapid change, one freedom feed forward is adopted, while another freedom output feedback is used to meet good servo tracking as well as disturbance and noise rejection; furthermore, to overcome the overshoot problem and acquire dynamic tuning,the integral is introduced in inner loop, and another integral controller is used in outer loop in order to guarantee steady errors; additionally, two performance weighting functions are designed to achieve robust specialty and control energy limit considering the uncertainties in system. As the schedule parameters change over large flight envelope, the stability of closed-loop LPV system is proved using Lyapunov inequalities. The simulation results show that the relative tracking errors of temperature and pressure are less than 0.5% with LPV μ synthesis controller. Meanwhile, compared with non-LPV μ synthesis controller in large uncertainty range, the proposed approach in this research can ensure robust servo performance of FET over the whole operational envelope.

关键词： Altitude ground test facilities Flight environment testbed Linear parameter varying Robust control Two-degree-of-freedom μ Synthesis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

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：