数值模拟加力燃烧室热态流场

本文对带有隔热屏、外冷却通道和稳定器的加力燃烧室的热态流场了数值模拟。加力燃烧室中的网格划分采用了非均匀交错网络系统，应用ＳＩＭＰＬＥ算法来求解各守恒方程。采用了双方程ｋ－ε紊流模型来预估紊流特性；采用简单的单步化学反应假设的ｋ－ε－ｇ紊流燃烧模型描述紊流燃烧；采用热通量法辐射模型来估算辐射通量和壁面温度。另外还研究了在加力燃烧室外冷却气流对加气燃烧室筒体壁面进行冷却后壁温分布情况，以及Ｖ型稳定器     

数值模拟涡轴发动机燃烧室流场

本文运用贴体坐标系统对涡轴发动机燃烧室流场进行了数值模拟。采用ＴＴＭ的非正交贴体坐标网格来处理燃烧室的曲线壁面边界。并把ＳＴＭＬＥ算法应用用到曲线坐标下求解各守恒方程，紊流粘度是用双方程ｋ－ε模型来估算，紊流燃烧模型采用按简单的化学反应系统假设的Ａｒｒｈｅｎｉｕｓ－ＥＢＵ模型，采用热流法辐射模型来估算辐射通量和燃烧室壁温及出口温度分布，计算结果令人满意。本文提供计算方法可供新型燃烧室设计方案选择用     

三维贴体坐标系下燃烧室中两相反应流的数值模拟

本文提供了现代航空发动机主燃烧室中三维两相燃烧流场的数值计算方法。气相场在欧拉坐标中用ＳＬＭＰＬＥ算法求解；液相场在拉格朗勒坐标系中用ＰＳＩＣ算法求解。本数值计算程序采用ｋ－ε双方程湍流模型，旋涡破裂湍流燃烧模型，六通量热辐射模型，采用了三维非正交曲线坐标系，压力交错网格。     

加力燃烧室污染特性计算

通过数值模拟方法，预估某型涡扇发动机加力燃烧室污染性能。采用κ－ε双方程模型描述紊流特性；采用修正的κ－ε－ｇ紊流燃烧模型和两步反应系统，来估算燃烧流场。其中ＣＯ和ＮＯ浓度都通过求解其紊流输运方程得到，而碳粒浓度采用多维经验分析法获取。对最大状态和加力状态等１８种飞行工况下加力室流场和污染性能进行了数值计算。     

设计,非设计工况下跨音平面叶栅气动性能数值模拟

在Ｃ－Ｈ网格中求解薄层Ｎ－Ｓ方程．对平面叶栅气动性能进行了数值模拟．采用双方程紊流模型．应用多重网格技术以加速收敛．对Ｍ１＝１．０～１．１．Ω＝１．０２～１．２３的ＤＶＦＬＲ跨音叶棚的气动性能进行了数值模拟，并与对应的实验结果作了详细的比较．     

锅炉一次风煤粉气流流过弯管时的数值模拟研究

对气固多相流动的数值模拟的方法和描述气固多相流动特性的数学模型进行了分析。通过分析和对煤粉气流流过弯管时的流动情况进行数值计算发现：采用Ｋ－ε双方程模型描述气相湍流模型,应用ＳＩＭ－ＰＬＥ算法计算气相速度场,然后采用ＦＳＲＴＳａｇｒａｎｇｅ法计算颗粒场特性,这是比较行之有铲的数值模拟管内气固多相流动的方法。     

考虑缝隙流模型的贯流式水轮机转轮内部三维流动

采用贯流式水轮机转轮内CFD分析软件，对设计工况下转轮内部的三维紊流场进行了数值模拟，并增加了缝隙流的流动模型：基于N－S方程和K－ε紊流模型，应用贴体座标和交错网格系统，用SIMPLEC算法对贯流式水轮机转轮内部的紊流进行数值模拟，得出其内部流场，压力场的分布情况及其水力效率和考虑缝隙的容积效率，最后将计算结果用Tecplot7进行处理，分别用矢量图和等值线表示其内部的流动状态和压力分布，并将普通模型和缝隙流模型分析，比较得出结论。     

锅炉一次风通过节流孔板时的数值模拟

本文对锅炉燃烧系统水平一次风管道内装了可调节流孔板后的空气－煤粉多相流动情况进行了数值模拟，通过数值模拟发现：采用ｋ－Σ双方程模型描述气相湍流模型，应用ＳＩＭＰＬＥ算法计算气相速度场，然后采用ＦＳＲＴ模型，Ｌａｇｒａｎｇｅ法计算颗粒场特性，这是一种计算管内气固多相流动的行之有效的数值模拟的方法。     

600MW锅炉炉内流动与燃烧过程的数值模拟

应用Euleriam/Lagrangian方法对四角切向燃烧炉内的流动、传热和燃烧过程者了数值模拟研究。为了获得较好的精确度，以实验数据为参照，进行了ＲＮＧ k－ε模型和 k－ε模型的比较，并采用新的方法对粒子紊流扩散进行了处理。最后，还对温度偏差进行了研究。     

隔热屏的流场计算及其屈曲分析

采用数值分析方法模拟了带有隔热屏、炎焰稳定器和尾喷口的加力燃烧室热态流场,并对隔热屏进行屈曲分析,计算中采用ｋ－ε双方程模型描述紊流特性,采用ＥＢＵ－Ａｒｒｈｅｎｉｕｓ燃烧模型计算化学反应速率。为了考虑火焰热辐射对气体温度分布的影响,用热通量法的辐射模型来估算辐射能量。在热态流场计算基础上,数值研究了发动机不同工况和隔热屏不同冷却结构及流量分配对加力室流场和隔热屏以及筒体壁温的影响。此外,还利用流场计算提供的气动和热负荷对隔热屏进行屈曲分析,根据实际情况,对隔热屏受力情况作了简化,把带波纹的隔热屏简化为圆柱壳,采用有限元方法对其屈曲模态和临界载荷进行了计算,取得了较为满意的结果。     

Numerical study of an annular gas turbine combustor with dump diffuser

INTRODUCTIONThemainfunctionofagasturbinediffusersystemistoreduceinletvelocityoftheflametubeandtoachieveminimaltotalpressurelossforimprovedcombustionprocesses.Inmoderngasturbinecombustors,thedumpdiffuserhasbeenwidelyused,becausethesuddenexpansionatpre...     

APPLICATION OF SCALAR MONTE CARLO PROBABILITY DENSITY FUNCTION METHOD FOR TURBULENT SPRAY FLAMES

Abstract

The objective of the present work is twofold: (1) extend the coupled Monte Carlo probability density function (PDF)/computational fluid dynamics (CFD) computations to the modeling of turbulent spray flames, and (2) extend the PDF/SPRAY/CFD module to parallel computing in order to facilitate large-scale combustor computations. In this approach, the mean gas phase velocity and turbulence fields are determined from a standard turbulence model, the joint composition of species and enthalpy from the solution of a modeled PDF transport equation, and a Lagrangian-based dilute spray model is used for the liquid-phase representation. The PDF transport equation is solved by a Monte Carlo method, and the mean gas phase velocity and turbulence fields together with the liquid phase equations are solved by existing state-of-the-art numerical representations. The application of the method to both open as well as confined axisymmetric swirl-stabilized spray flames shows good agreement with the measured data. Preliminary estimates indicate that it is well within reach of today's modern parallel computer to do a realistic gas turbine combustor simulation within a reasonable turnaround time. The article provides complete details of the overall algorithm, parallelization, and other numerical issues related to coupling between the three solvers.     

Optimization of Gas Turbine Combustor Mixing for Improved Exit Temperature Profile

In this article, a design optimization technique for mixing in a gas turbine combustor is presented. The technique entails the use of computational fluid dynamics and mathematical optimization to optimize the combustor exit temperature profile. Combustor geometric parameters were used as optimization design variables. This work does not intend to suggest that combustor exit temperature profile is the only performance parameter important for the design of gas turbine combustors. However, it is a key parameter of an optimized combustor that is related to the power output and durability of the turbine. The combustor in this study is an experimental liquid-fuelled atmospheric combustor with a turbulent diffusion flame. The computational fluid dynamics simulations use a standard k-? model. The optimization is carried out with the Dynamic-Q algorithm, which is specifically designed to handle constrained problems where the objective and constraint functions are expensive to evaluate. The optimization leads to a more uniform combustor exit temperature profile than with the original one.     

LDA在燃气轮机燃烧室流场测量中的应用

介绍了激光多普勒测速技术在燃气轮机燃烧室内部流场测试的应用，阐述了LDA的基本原理和模型燃烧室内光学路径的实现方法，同时作者利用双相位多普勒分析仪DualPDA (Cual Phase Doppler Anemometer)对模型燃烧室内部流场进行了二维冷态测试，获得了大量的原始数据，为深入研究燃烧室内部气流特性提供了实验基础。     

燃气轮机环形燃烧室内燃烧流动的数值模拟

对一个复杂的GE—F101型工业燃气轮机环形燃烧室，采用Reynolds应力湍流模型(RSM)、EBU—Arrhenius湍流燃烧模型和六通量热辐射模型描述其燃烧流动，应用FLUENT软件进行了三维化学反应流场的数值模拟研究。研究结果表明：旋流和燃料进口射流对燃烧室流内温度和流场分布有着重要的影响；利用数值手段得到燃烧室出口的温度分布以判断其能否满足透平叶片进口温度的要求是可行的；燃烧室工作压强对出口的NO分布有着重要影响。在燃用气体燃料时，燃气轮机的NO排放主要来自于热NO，瞬时NO只占很小一部分。图11参6     

Large-eddy simulation of two-phase spray combustion for gas turbine combustors

In three-dimensional arbitrary curvilinear coordinates, an Eulerian–Lagrangian formulation is applied to large-eddy simulation (LES) of instantaneous gas–liquid two-phase turbulent combustion flows in gas turbine combustors. Three dimensional block-structured grids are generated by zone method and solving a system of elliptic partial differential equations. The k-equation sub-grid scale model is used to simulate the sub-grid eddy viscosity and the EBU combustion sub-grid scale model is employed to predict the chemical reaction rate. The gas-phase governing equations are solved with SIMPLE algorithm and hybrid scheme in non-staggered grid system. A stochastic separated flow formulation is used to track the droplet trajectories velocities, size and temperature history by Lagrangian equations of motion and thermal balance. Multi-zone coupling method is employed to transport data between interfaces. The influences of two different primary hole positions and three different fuel–air ratios on turbulent two-phase reacting flows are calculated. Predictions are in reasonable agreement with the measured velocity using PIV system and temperature, species concentration measurements at the exit. It is shown that the present approach may be used to study spray combustion flow fields for guiding the design of advanced gas turbine combustors.     

多流体模型在燃气轮机燃烧室三维反应流中的应用

对一种模型燃气轮机燃烧室中的三维反应流进行了数值模拟，模型燃烧室的燃料是CH4，燃烧类型是预混燃烧，在数值模拟过程中，采用了Spalding于1995年提出来的多流体模型来对燃烧室中的湍流预混燃烧进行了数值模拟，在数值模拟过程中考虑了辐射问题，采用了六通量辐射模型。通过数值模拟给出了速度，压力，湍流脉动动能，湍流动能耗散率，焓值，湍流粘度，温度，密度，燃烧产物质量分数，氧的质量分数，燃料/空气混合比，燃料质量分数，空间三个方向的辐射热通量以及各种流体的质量分数等变量的分布情况，此外，还采用传统的旋涡破碎模型对此燃烧室进行了数值模拟，并对两种方法的结果进行了分析比较，由分析可以看出多流体模型的结果接近于实际情况，对模型燃烧室进行三维反应流数值模拟的工作为今后对实际燃烧室反应流的数值模拟打下了一定的基础。     

Modelling of combustion performances and emission characteristics of coal gases in a model gas turbine combustor

In recent years, gas mixtures are being used as alternative fuels in combustors. These gas mixtures are obtained by different methods. For instance, coal gasification and carbonization as coal have the largest reserves among fossil fuels. Gas mixtures obtained via coal gasification and carbonization are called water gas, generator gas, town gas and coke oven gas. These fuels contain various gases. As a result of this, heating values of fuels are also different. Therefore, combustion performances and emission characteristics of these fuels need to be investigated. In this study, combustion performances and emissions including CO, CO₂ and NO_X of water gas, generator gas, town gases, coke oven gas and methane were numerically investigated in a model gas turbine combustor. The numerical modelling of turbulent nonpremixed diffusion flames has been performed in this combustor. Mathematical models used in this study involved the k–ε model of turbulent flow, the PDF/mixture fraction model of nonpremixed combustion and P‐1 radiation model. A CFD code ANSYS Fluent was used for all numerical investigations. Temperature distributions of axial and radial directions were determined. A NO_X post‐processor was used for the prediction of NO_X emissions from the gas turbine combustor. Modelling was performed for 60 kW thermal power and different equivalance ratios (i.e. Ф = 0.91, Ф = 0.77 and Ф = 0.67). The studied type 1 model gas turbine combustor was modelled for Ф = 0.91 equivalance ratio. Then, Other equivalance ratios were analysed for type 2 model gas turbine combustor. The effect of dilution air on combustion performances and emission characteristics was also investigated. It is concluded that the coke oven gas, the town gas I, town gas II and the water gas are appropriate for usage as alternative fuel, whereas the generator gas is not suitable for gas turbine combustors. Copyright © 2013 John Wiley & Sons, Ltd.     

Numerical Study of Spray Dispersion in a Premixing Chamber for Low-NOx Engines

IntroductionThe present work is devoted to particle dispersionin confined two-phase turbulent jets, which has become amajor domain of research attracting increasingly interestand with challenging fundamental aspects. Describingthe motion of a dispersed phase is complex and is ofgreat interest in several practical systems. Theapplications that require the solution of this problem areas varied as the dispersion of passive pollutant particlesin the atmosphere to combustion systems with dispersing…     

燃气轮机燃烧室流场数值计算研究及分析

对燃气轮机逆流式环形燃烧室,热态三维流场的数值模拟问题进行了研究,建立了三维计算模型,生成了数值计算网格。数值模拟研究表明,改变燃烧室的几个结构参数,可以得到更加合理的流场。通过对关键截面的流动分析,可以判断燃烧室设计的合理性,为进一步优化燃烧室结构设计、改善流场奠定了基础。