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Large eddy simulation of unsteady transitional flow on the low-pressure turbine blade

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Science China(Technological Sciences) 2014年第9期57卷 1761-1768页

作者： WANG YunFei chen Fu LIU HuaPing chen huanlong School of Energy Science and Engineering Harbin Institute of Technology

The aim of this paper is to predict the phenomenon of laminar separation, transition and reattachment in a low-pressure turbine （LPT）. Self-developed large eddy simulation program of compressible N-S equations was used to describe the flow structures of T 106A LPT blade profile at Reynolds number of 1.1×10^5 based on the exit isentropic velocity and chord length. The com- putational results show the distributions of time-averaged wall-static pressure coefficient and mean skin-friction coefficient on the blade surface. The locations of laminar separation and reattachment points occur around 87% and 98% axial chord, which agree well with experiment data. The two-dimensional shear layer is gradually unstable along the downstream half of the suc- tion side as a result of the spanwise fluctuation and the roll up of shear layer via Kelvin-Helmholtz （KH） instability. Three-dimensional motions appear near 84% axial chord which later triggers spanwise vortexes and streamwise vortexes, leading to transition to turbulence in the separation bubble. Through introducing the concept of dissipation function, the high loss mainly comes from the places where strong shear layer and intense fluctuation exist. Furthermore, the separation region is only an accumulation center of the low-energy fluid rather than an area of loss source.

关键词： large eddy simulation low-pressure turbine flow separation transition

Design and Numerical Simulation on Coupled Flow Field of Radial Turbine with Air-Inlet Volute

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Transactions of Tianjin University 2015年第2期21卷 153-160页

作者：王云飞陈焕龙陈浮 School of Energy Science and Engineering Harbin Institute of Technology

As one of the core components of turbocharger or micro-turbine, radial turbine has the features of small size and high rotation speed. In order to explore the design method and flow mechanism of the turbine with a volute, a centimeter-scale radial turbine with a vaneless air-inlet volute was designed and simulated numerically to investigate the characteristics of the coupled flow field. The results show that the wheel efficiency of single passage computation without the volute is 80.1%. After accounting for the factors of the loss caused by the volute and the interaction between each passage, the performance is more accurate according to the whole flow passage computation with the volute. High load region gathers at the mid-span and the efficiency declines to 76.6%. The performance of the volute whose structure angle of the trapezoid section is equal to 70 degree is better. Unlike uniform inlet condition in single passage, more appropriate inlet flow for the impeller is provided by the rectification effect of the volute in full passage calculation. Flow parameters are distributed more evenly along the blade span and are generally consistent between each passage at the outlet of the turbine.

关键词： radial turbine aerodynamic design whole flow passage air-inlet volute

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吐哈油田天然气利用途径

天然气工业 2000年第2期20卷 90-92页

作者：李国诚陈焕龙吐哈油田开发第一事业部

新疆占全国总面积六分之一 ,其三大盆地蕴藏着丰富的天然气资源 ,且天然气市场潜力很大 ,预测2 0 0 0年天然气需求量为 40× 1 0 8m3,其中 95%用于工业。吐哈油田 1 997年公布储量为 669 2 7× 1 0 8m3,1 997年开始向乌鲁木齐市供气 4×... 详细信息

新疆占全国总面积六分之一 ,其三大盆地蕴藏着丰富的天然气资源 ,且天然气市场潜力很大 ,预测2 0 0 0年天然气需求量为 40× 1 0 8m3,其中 95%用于工业。吐哈油田 1 997年公布储量为 669 2 7× 1 0 8m3,1 997年开始向乌鲁木齐市供气 4× 1 0 8m3/a ,主要用于尿素生产。由于吐哈油田天然气资源综合利用起步较晚 ,当前还存在天然气利用不充分 ,每年还有不少气在放空 ;所生产的LPG面临需求量下降 ,稳定轻烃不好利用等问题。为此 ,结合新疆地区地广人稀 ,交通不便 ,资源分散等特点 ,提出了吐哈油田的天然气宜在新疆内消化 ,加工成产品或中间产品面向全国的思路 ,寻求依靠科技发展天然气综合利用的有效途径。

关键词：吐哈油田天然气资源天然气利用

Flow Diagnosis and Optimization Based on Vorticity Dynamics for Transonic Compressor/Fan Rotor

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Open Journal of Fluid Dynamics 2017年第1期7卷 40-71页

作者： huanlong chen Mark G. Turner Kiran Siddappaji Syed Moez Hussain Mahmood Institute of Propulsion Theory and Technique Harbin Institute of Technology Harbin China Aerospace Engineering Department University of Cincinnati Cincinnati OH USA

This paper presents two optimized rotors. The first rotor is as part of a 3-blade row optimization (IGV-rotor-stator) of a high-pressure compressor. It is based on modifying blade angles and advanced control of curvature of the airfoil camber line. The effects of these advanced blade techniques on the performance of the transonic 1.5-stage compressor were calculated using a 3D Navier-Stokes solver combined with a vortex/vorticity dynamics diagnosis method. The first optimized rotor produces a 3-blade row efficiency improvement over the baseline of 1.45% while also improving stall margin. The throttling range of the compressor is expanded largely because the shock in the rotor tip area is further downstream than that in the baseline case at the operating point. Additionally, optimizing the 3-blade row block while only adjusting the rotor geometry ensures good matching of flow angles allowing the compressor to have more range. The flow diagnostics of the rotor blade based on vortex/vorticity dynamics indicate that the boundary-layer separation behind the shock is verified by on-wall signatures of vorticity and skin-friction vector lines. In addition, azimuthal vorticity and boundary vorticity flux (BVF) are shown to be two vital flow parameters of compressor aerodynamic performance that directly relate to the improved performance of the optimized transonic compressor blade. A second rotor-only optimization is also presented for a 2.9 pressure ratio transonic fan. The objective function is the axial moment based on the BVF. An 88.5% efficiency rotor is produced.

关键词： Transonic Compressor Control Curvature Optimization Vorticity Dynamics BVF Azimuthal Vorticity

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航天器轨道计算精度数值分析

西北工业大学学报 2009年第5期27卷 635-640页

作者：陈欢龙周军刘莹莹西北工业大学精确制导与控制研究所陕西西安710072

文章介绍了航天器轨道计算的基本流程,从数值上分析了时间和坐标转换、各种轨道摄动力及它们在不同的计算条件下,对轨道数值计算精度的影响,为各种应用提供简明信息。部分摄动如光压摄动、日月引力摄动对轨道计算精度的影响随着高度的... 详细信息

文章介绍了航天器轨道计算的基本流程,从数值上分析了时间和坐标转换、各种轨道摄动力及它们在不同的计算条件下,对轨道数值计算精度的影响,为各种应用提供简明信息。部分摄动如光压摄动、日月引力摄动对轨道计算精度的影响随着高度的增加而增大,而另一些如大气阻力及地球引力场模型的影响随着高度的增大而减小;对于低轨道航天器,由于飞行速度较快,总体加速度较大,因此误差的累积速度也较快,各种摄动的影响均较为明显。

关键词：航天器轨道摄动计算精度数值分析

Effects of Vortex Generator Jet on Corner Separation/Stall in High-Turning Compressor Cascade

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Transactions of Tianjin University 2016年第6期22卷 555-562页

作者：刘华坪李得英陈焕龙张东飞 School of Energy Science and Engineering Harbin Institute of Technology Harbin 150001 China Beijing Electro-Mechanical Engineering Institute CASIC Beijing 100074 China

The effects of the vortex generator jet(VGJ)attached at the endwall on the corner separation/stall control are investigated by numerical simulation in a high-turning linear compressor cascade. The results show that the corner separation could be reduced significantly, which results in a wider operation range as well as a more uniform exit flow angle and total pressure profile. At the near-stall operation point, the maximum relative reduction of the total pressure loss is up to 32.5%,, whereas the jet mass ratio is less than 0.4%,. Based on the analysis of the detailed flow structure, three principal effects of the VGJ on the endwall cross flow and corner separation are identified. One is to increase the tangential velocity component opposite to cross flow, thus inhibiting the endwall secondary flow near the jet exit. The second is to suppress the pitchwise extension of the passage vortex as an air fence. The third is to sweep the low energy fluids towards the mainstream on the up-washed side and to transport the mainstream fluids to the endwall to reenergize the boundary layer on the down-washed side.

关键词： vortex generator jet corner separation high turning compressor loss reduction

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三轴气浮台多体动力学建模与仿真

西北工业大学学报 2010年第3期28卷 332-337页

作者：陈欢龙周军刘莹莹牟小刚西北工业大学精确制导与控制研究所陕西西安710072 北京控制工程研究所北京100080

为了研究多体卫星的地面物理仿真试验方法,根据动量矩定理,文章建立了转动附件与三轴气浮台中心刚体直联以及级联情况下的动力学模型。针对带一个附件的三轴气浮台,利用Simulink进行了开环动力学仿真,结果显示,附件的转动对台体的姿态... 详细信息

为了研究多体卫星的地面物理仿真试验方法,根据动量矩定理,文章建立了转动附件与三轴气浮台中心刚体直联以及级联情况下的动力学模型。针对带一个附件的三轴气浮台,利用Simulink进行了开环动力学仿真,结果显示,附件的转动对台体的姿态耦合特性明显,如果不对由于附件转动引起的气浮台系统总质心的变化进行补偿,重力静不平衡力矩将严重影响物理仿真过程的进行。转动附件的质心偏离转动轴或转动中心的程度也决定了附件转动对本体的影响。根据该动力学方程,通过对转动部件质量特性的精确建模,可以分析及计算部件转动对气浮台本体运动特性的影响。

关键词：气浮台多体动力学转动附件数值仿真

某大折转角压气机静叶分叉改型设计及其尾迹流场

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航空动力学报 2018年第6期33卷 1381-1392页

作者：陈焕龙李林熹刘华坪余孟晗哈尔滨工业大学能源科学与工程学院哈尔滨150001

针对高负荷风扇/压气机叶栅流道中由于强逆压力梯度而易于诱发大尺度流动分离的问题,基于增加叶栅稠度以减小叶片通道中压力梯度的思想,结合三维叶片造型技术设计了一种分叉叶片结构,应用数值方法对分叉叶片通道气动性能及叶栅尾迹流场... 详细信息

针对高负荷风扇/压气机叶栅流道中由于强逆压力梯度而易于诱发大尺度流动分离的问题,基于增加叶栅稠度以减小叶片通道中压力梯度的思想,结合三维叶片造型技术设计了一种分叉叶片结构,应用数值方法对分叉叶片通道气动性能及叶栅尾迹流场特性进行了预测与分析。研究结果表明:与原型叶片通道相比,在设计冲角(0°)及正冲角条件下,分叉叶片通道出口能量损失降低,气流折转能力增加,栅后尾迹亏损大幅度减少。

关键词：扩压叶栅压力梯度分叉叶片尾迹二次流

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降低涡轮动叶气动激振力的优化设计方法

航空动力学报 2024年第11期39卷 143-151页

作者：陈焕龙秦勇蔡文哲王兵颜廷松哈尔滨工业大学能源科学与工程学院哈尔滨150001 北京动力机械研究所北京100074

针对涡轮级叶列之间流场干扰诱发下游动叶非定常气动激振力的物理问题,提出了一种涡轮导叶与动叶联合匹配优化以降低动叶气动激振力的气动设计方法。研究表明:采用该方法不仅使得所研究涡轮动叶气动激振力的时均值下降8%,而且其他相位... 详细信息

针对涡轮级叶列之间流场干扰诱发下游动叶非定常气动激振力的物理问题,提出了一种涡轮导叶与动叶联合匹配优化以降低动叶气动激振力的气动设计方法。研究表明:采用该方法不仅使得所研究涡轮动叶气动激振力的时均值下降8%,而且其他相位的动叶气流激振特性也获得改善,说明了该气动优化设计方法的可行性。此外,优化后的涡轮导叶具有明显的弯掠特征,弯掠导叶有助于降低下游动叶的非定常气动激振力,这是涡轮非定常气动设计技术对于“弯曲叶片”流动机理的新认识,非常值得开展更加深入的研究工作。

关键词：非定常气动激振力流动匹配气动优化尾迹干扰激波