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Interaction mechanisms of shock waves with the boundary layer and wakes in a highly-loaded NGV using hybrid rans/les

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Chinese Journal of Aeronautics 2020年第1期33卷 149-160页

作者： Xiutao BIAN Qingsong WANG Xinrong SU Xin YUAN Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Tsinghua UniversityBeijing 100084China

Accurate predictions of Shock Waves and Boundary Layer Interaction(SWBLI)and strong Shock Waves and Wake Vortices Interaction(SWWVI)in a highly-loaded turbine propose challenges to the currently widely used Reynolds-Averaged Navier-Stokes(rans)*** this work,the SWBLI and the SWWVI in a highly-loaded Nozzle Guide Vane(NGV)are studied using a hybrid rans/les *** Turbulence Kinetic Energy(TKE)budget and the Proper Orthogonal Decomposition(POD)method are used to analyze flow *** show that this hybrid rans/les method can obtain detailed flow structures for flow mechanisms *** shock waves induce boundary layer separation,while the presence of a separation bubble can in turn lead to a Mach reflection *** shock waves cause trailing-edge vortices to break clearly,and the wakes,in turn,can change the shocks intensity and ***,the Entropy Generation Rate(EGR)is used to analyze the irreversible *** turns out that the SWWVI can reduce the flow field *** are several weak shock waves in the NGV flow field,which can increase the irreversible *** work offers flow mechanisms analysis and presents the EGR distribution in SWBLI and SWWVI areas in a transonic turbine blade.

关键词： Boundary layer Hybrid rans/les NGV Shock waves Wakes

Application of the hybrid rans/les method on the hydraulic dynamic performance of centrifugal pumps

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Journal of Hydrodynamics 2019年第3期31卷 637-640页

作者： Zheng-chuan Zhang Hong-xun Chen Zheng Ma Qun Wei Jian-wu He Hui Liu Chao Liu Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China Chinese Ship Scientific Research Center Wuxi 214082 China College of Civil Engineering and Architecture Nanchang University Nanchang 330031 China Shanghai Marine Equipment Research Institute Shanghai 200031 China

The nonlinear hybrid rans/les method has been developed considering the simulation efficiency and accuracy to simulate the hydraulic dynamic characteristics of the centrifugal pump. It has been proved that the nonlinear hybrid rans/les method could effectively capture the unsteady flow structure and pressure pulsation in 2?D centrifugal pumps. To further investigate the hydraulic dynamic performance of a redesigned 3-D-gap drainage centrifugal pump, the nonlinear hybrid rans/les method is employed. Both numerical simulation and experimental results show that the hydraulic performance and pressure pulsation characteristics of the 3-D-gap drainage impeller centrifugal pump are significantly enhanced.

关键词： 3-D gap drainage blades nonlinear hybrid rans/les method pressure pulsation

Numerical study on turbulent mixed convection in a vertical plane channel using hybrid rans/les and les models

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Chinese Journal of Chemical Engineering 2020年第1期28卷 1-8页

作者： Puxian Ding Shuangfeng Wang Kai Chen Key Laboratory of Enhanced Heat Transfer and Energy Conservation of the Ministry of Education School of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou 510640China

Two Delayed-Detached Eddy Simulation(DDES) models, and a Large-Eddy Simulation(les) model are used to investigate the turbulent flows and mixed convection between a hot plate and a cold plate via the software FLUENT. The two DDES models include Production-limited DDES(PL-DDES) and Improved DDES(IDDES) *** Wall-Adapting Local Eddy-Viscosity(WALE) model is the used les model. The numerical computations are performed at Reynolds number Reb= 4494 and different Richardson numbers Ri = 0.025, 0.048, 0.1. The comparing data is from the Direct Numerical Simulation(DNS) at Reb= 4494 and Ri = 0.048. The comparison reveals that the two DDES models have better performance in predicting time-averaged parameters than the WALE model in the aiding flow. The best predicted time-averaged results are obtained by the PL-DDES model in the opposing flow. Furthermore, the results of different Ri obtained by the PL-DDES model agree well with the DNS data.

关键词： Turbulent mixed convection Hybrid rans/les model PL-DDES model WALE model Vertical plane channel

耦合rans/les模型与LEE方程的气动噪声混合预测方法

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西北工业大学学报 2017年第6期35卷 990-997页

作者：余培汛白俊强杨海潘凯西北工业大学航空学院陕西西安710072 中国飞机强度研究所航空声学与动强度航空科技重点实验室陕西西安710065

耦合湍流速度生成模型与线化欧拉方程,建立了气动噪声混合预测方法。该混合方法的湍流速度生成采用了非定常求解NS方程方式,为声传播方程提供了可靠的源项。声源的传播计算选用线化欧拉方程,其时空离散采用低色散低耗散高阶格式,远场边... 详细信息

耦合湍流速度生成模型与线化欧拉方程,建立了气动噪声混合预测方法。该混合方法的湍流速度生成采用了非定常求解NS方程方式,为声传播方程提供了可靠的源项。声源的传播计算选用线化欧拉方程,其时空离散采用低色散低耗散高阶格式,远场边界选用了无分裂形式的理想匹配层边界条件。流场网格与声场网格的湍流速度信息交换采用了高阶插值算法。针对空腔标模M219的气动噪声预测,分别采用了统计声源与声传播(SNGR)方法、rans/les+LEE方法进行了计算分析。通过对比声源的分布、量级,以及监测点的声压曲线及声压级频谱曲线,分析可得出:rans/les+LEE方法能准确捕捉空腔各阶模态的声压级峰值。经数值模拟结果与实验结果的对比,表明rans/les+LEE方法相比于SNGR方法更适合模拟空腔这类流激振荡现象引起的声传播问题。

关键词：湍流速度生成模型线化欧拉方程气动噪声统计声源与声传播 rans/les 空腔

超声速湍流流场的rans/les混合计算方法研究

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空气动力学学报 2009年第6期27卷 723-728页

作者：袁先旭邓小兵谢昱飞张志成中南大学轨道交通安全教育部重点实验室湖南长沙410075 中国空气动力研究与发展中心四川绵阳621000

采用对接/拼接网格技术,建立了基于分区混合和基于湍流尺度混合的双重rans/les混合计算模型,并对环翼低速绕流、翼型跨声速绕流和球锥带凹窗外形二维超声速绕流进行了初步的数值模拟。环翼和翼型绕流计算表明,该混合模型可给出较合理的... 详细信息

采用对接/拼接网格技术,建立了基于分区混合和基于湍流尺度混合的双重rans/les混合计算模型,并对环翼低速绕流、翼型跨声速绕流和球锥带凹窗外形二维超声速绕流进行了初步的数值模拟。环翼和翼型绕流计算表明,该混合模型可给出较合理的湍流宏观平均量;球锥带凹窗外形二维超声速绕流计算表明,该混合模型可得到超声速瞬态湍流脉动流场,凹窗处存在复杂的旋涡结构和波系结构,呈现较大尺度的脉动。但该模型还需要进一步的考核验证。

关键词：气动光学效应 rans les rans/les

Joint rans/les Modeling of Flameless Combustion

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Energy and Power Engineering 2011年第5期3卷 616-624页

作者： Vladimir L. Zimont Valerio Battaglia 不详

We present our timesaving joint rans/les approach (we originally developed it for numerical simulations of turbulent premixed combustion) to simulate flameless combustion with separate injection of gas fuel and strong exhaust gas recirculation. It is based on successive rans/les numerical modeling where part of the information (stationary average fields) is achieved by rans simulations and part (instantaneous nonstationary image of the process) by les. The latter is performed using the rans field of mean dissipation rate to model the sub-grid turbulent viscosity in the context of the Kolmogorov theory of small-scale turbulence. We analyze flameless combustion in the FLOX? combustor where we also simulate non-premixed flame combustion used for preliminary heating of the combustor. Different regimes take place using different systems of air injection. We applied for both regimes the simple assumption of “mixed is burnt”. The main results are the following: 1) rans simulations demonstrate for used two injection systems respectively more compact flame and distributed flameless combustion. 2)There is agreement between rans and corresponding les results: rans and averaged les profiles of the velocity and temperature are in reasonable agreement. 3) les modeling with Kolmogorov independent on time sub-grid viscosity reproduce instantaneous image of the process including the vortex structures. Probably due to using an annular injector system for air the instantaneous field of the temperature demonstrate significant irregularity in the beginning of the burner, which in an animation looks like moving coherent structures. 4) In the joint rans/les approach the computer time of the les sub-problems is much shorter than classic les modeling due to using time independent subgrid transport coefficients and avoiding long-continued simulations, which are necessary for averaging of instantaneous les fields. Practically in our simulations time consuming of the les sub-problem was only s

关键词： Flameless Combustion Joint rans/les Modeling FLOX Burner

基于rans/les混合方法的风力机数值模拟分析

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基于RANS/LES混合方法的风力机数值模拟分析

rans and les Modeling of the GE10 Burner

第九届全国流体力学学术会议

作者：杨小川王运涛洪俊武孟德虹孙岩李伟中国空气动力研究与发展中心计算空气动力研究所

基于自主研发的大型"亚跨超CFD软件平台"(TRIP3.0),初步开展了基于rans/les混合方法的NREL PhaseⅥ风力机标模非定常数值模拟分析,控制方程为雷诺平均N-S方程,采用有限体积法离散控制方程,离散方程的求解方法为时间方向采用"双时间步"... 详细信息

基于自主研发的大型"亚跨超CFD软件平台"(TRIP3.0),初步开展了基于rans/les混合方法的NREL PhaseⅥ风力机标模非定常数值模拟分析,控制方程为雷诺平均N-S方程,采用有限体积法离散控制方程,离散方程的求解方法为时间方向采用"双时间步"方法求解,空间方向无粘项离散采用MUSCL-Roe格式,并引入多重网格和并行计算技术加速求解。通过计算对比SA、SST湍流模型结果得到:在低风速工况下,基于rans/les混合方法得到的压力分布与SA和SST基本吻合,且与试验值吻合较好;而在高风速工况下,rans/les混合方法得到的叶尖压力分布较SA和SST更接近试验值;在捕捉空间涡流能力上,基于rans/les混合方法较SA和SST更强,得到的空间涡结构更明显。

关键词：风力机非定常计算 TRIP3.0 rans/les 动态拼接网格

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Energy and Power Engineering 2011年第5期3卷 607-615页

作者： Valerio Battaglia Roberto Modi Vincent Moreu Vladimir Zimont 不详

The paper presents 1) the numerical results of rans (Reynolds Averaging Navier-Stokes) simulations for two versions of the premixed combustion GE10 burners: the old one with non-premixed and modified one with swirled premixed pilot flames;and 2) the numerical results of joint rans/les (Large Eddy Simulation) modelling of the ONERA model burner and a simplified GE10 combustor. The original joint rans/les approach is based on using the Kolmogorov theory for modelling sub-grid turbulence and combustion intensity and using rans numerical results for closure the les model equations. The main conclusion is that developed joint rans/les approch is the efficient timesaving tool for simulations both the average and instantaneous fields of parameters in gas turbine and boiler burners with premixed combustion.

关键词： Turbulent Premixed Combustion Gas Turbine Burner Joint rans/les Simulation

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战斗机垂尾脉动压力数值模拟

航空学报 2016年第8期37卷 2472-2480页

作者：孟德虹孙岩王运涛李伟中国空气动力研究与发展中心计算空气动力研究所绵阳621000 中国空气动力研究与发展中心空气动力学国家重点实验室绵阳621000

在亚跨超计算流体力学(CFD)软件平台(TRIP)上开发了基于rans/les混合思路的IDDES流动模拟技术,并通过NACA0021翼型60°大迎角分离流动与串列圆柱绕流模拟对rans/les混合方法的精确度进行了验证,针对某战斗机外形的垂尾脉动压力开展了数... 详细信息

在亚跨超计算流体力学(CFD)软件平台(TRIP)上开发了基于rans/les混合思路的IDDES流动模拟技术,并通过NACA0021翼型60°大迎角分离流动与串列圆柱绕流模拟对rans/les混合方法的精确度进行了验证,针对某战斗机外形的垂尾脉动压力开展了数值模拟研究。战斗机来流马赫数为0.1,基于全机长度的雷诺数为2×106,模型迎角为20°、30°和40°。分别通过脉动压力系数、脉动压力功率谱密度、空间流动结构以及侧向力响应曲线等对战斗机的垂尾脉动压力进行了分析。脉动压力模拟结果表明:当垂尾完全沉浸在边条翼脱体涡破碎后的宽频湍流脉动气流中时,垂尾翼梢位置的脉动压力会发生明显的增大。

关键词：战斗机垂尾脉动压力 rans/les 计算流体力学(CFD)