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A numerical simulation strategy for a compressor’s underlying axisymmetric characteristic and its application in body force model

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Chinese Journal of Aeronautics 2024年第8期37卷 79-90页

作者： Shijie LIU Tianyu pan qiushi LI ` School of Energy and Power Engineering Beihang UniversityBeijing 100191China Research Institute of Aero-Engine Beihang UniversityBeijing 100191China Key Laboratory of Fluid and Power Machinery Ministry of EducationXihua UniversityChengdu 610039China

Accurate prediction of the aerodynamic response of a compressor under inlet distortion is crucial for next-generation civil aircraft,such as Boundary Layer Ingestion(BLI)silent ***,research on the Body Force(BF)model plays a significant role in achieving this ***,distorted inlet airflow can lead to varying operating conditions across different spatial locations of the compressor,which may cause some regions to operate outside the stability ***,the accuracy of BF model simulations might be *** address this issue,this paper proposes a numerical simulation strategy for acquiring the steady axisymmetric three-dimensional flow field of a compressor operating at low mass flow rates,which is known as the Underlying Axisymmetric Pressure Rise Characteristic(UAPRC).The proposed simulation accounts for two different rotor speeds of a transonic compressor and identifies initial positions in the flow field where deterioration occurs based on prior experimental ***,simulation results are incorporated into the BF model to replicate hub instability observed in *** results demonstrate that this strategy provides valid predictions of the UAPRC of the compressor,thereby addressing the limitations associated with the BF model.

关键词： Compressor partial instability Performance at low mass flow rates Underlying axisymmetric pressure rise characteristic Novel simulation strategy Body force model

南水北调中线冬季冰情变化特征及输水能力提升策略研究

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水利学报 2024年第4期55卷 389-402页

作者：郭新蕾潘佳佳苑希民王军罗秋实苏霞流域水循环模拟与调控国家重点实验室中国水利水电科学研究院北京100038 天津大学天津300072 合肥工业大学安徽合肥230009 黄河勘测规划设计研究院有限公司河南郑州450003 中国南水北调集团中线有限公司北京100038

南水北调中线工程冰期输水能力受限已成为制约工程安全运行和社会效益发挥的巨大障碍。认识和辨析通水以来中线干渠冬季水温冰情演变规律及影响机理,是中线干渠冬季输水能力提升亟需解决的关键问题。本文基于2011—2023年中线干渠连续1... 详细信息

南水北调中线工程冰期输水能力受限已成为制约工程安全运行和社会效益发挥的巨大障碍。认识和辨析通水以来中线干渠冬季水温冰情演变规律及影响机理,是中线干渠冬季输水能力提升亟需解决的关键问题。本文基于2011—2023年中线干渠连续12个冬季的气象、水力、冰情等原型观测资料,分析了中线干渠水温冰情时空分布本底和特征规律,明晰了影响中线干渠冰凌生消的关键因素,针对性提出了冬季输水能力提升的相关应对策略。分析表明:通水以来冰情发生的范围和时间相比理论预想偏小、偏短,冰凌影响区为七里河倒虹吸至北拒马河暗渠段,冰塞风险区为滹沱河倒虹吸至北拒马河暗渠段,多年平均冰厚15 cm,历史极端冰塞厚2.9 m,冰凌壅水最高值0.73 m;干渠冬季水温由南向北递减,依次出现岸冰、流冰和冰盖,日均气温转负后相应的断面平均测量水温在2.5、1.0和0.25℃左右,且沿程水温下降速率与流量和气温呈负相关,即增大输水流量可减缓水温下降速度;影响冰凌生消的关键因素是气温、流量、太阳辐射和风速,典型年如2016年的严重冰情与1月低累计负积温、大输水流量和短时寒潮叠加有关,漕河等渡槽失温快产冰量大与风速密切相关。基于上述分析,未来可考虑结合气象、水情、冰情实时监测和智能预警预报,建立水温-水量-水力协同调控和动态调度技术体系,重点从缩短冰期输水时长、降低冰情影响范围、优化关键控制指标和挖潜渠道防冰塞性能等多方面全面提升南水北调中线工程冬季输水能力。

关键词：水温冰情时空分布南水北调中线冬季防凌输水能力

Effects of the radial blade loading distribution and B parameter on the type of flow instability in a low-speed axial compressor

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Chinese Journal of Aeronautics 2018年第7期31卷 1470-1479页

作者： qiushi LI Simin LI Tianyu pan National Key Laboratory of Science and Technology on Aero-Engine Aerothermodynamics Collaborative Innovation Center for Advanced Aero-Engine School of Energy and Power Engineering Beihang University Department of Mechanical Engineering and Materials Science Duke University

Previous studies showed that an axisymmetric hub-initiated disturbance defined as partial surge may initiate the stall of a transonic compressor; to reveal the instability evolution under full-span incompressible flow for different levels of hub loading and B parameter, an experimental investigation is conducted on a single-stage low-speed compressor. Experimental results show that under a uniform inflow condition without inlet flow distortion, a modal-type stall inception dominates in this low-speed compressor. When an inlet screen introducing hub distortion is used to increase the hub loading, a compressor stall is initiated by a modal wave, but large disturbances are present in the hub region before the compressor stall, which become stronger as the hub loading increases. Under high hub loading and large B parameter（implemented by adding hub distortion through an inlet screen and enlarging the outlet plenum volume, respectively）, a compressor stall is triggered by an axisymmetric hub-initiated disturbance, which is much different from the modal-like disturbances. The beginning of this axisymmetric disturbance may be captured over 800 rotor revolutions prior to the onset of stall, and the amplitude grows with time. The disturbance is hub-initiated because the disturbance signal at the hub is detected much earlier than that at the tip; meanwhile, the frequency of this axisymmetric disturbance changes with the length of the inlet duct. The characteristics of instability evolution in the low-speed compressor are also compared with those in a transonic compressor.

关键词： Axisymmetric disturbance B parameter Flow instability Low-speed axial compressor Radial blade loading distribution

Instability Inception of a Single Rotor Embedded in a Transonic Stage with Partial Surge Inception

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Journal of Thermal Science 2022年第1期31卷 130-140页

作者： pan Tianyu WU Wenqian ZHENG Mengzong LI qiushi Reserach Institute of Aero-Engine Beihang UniversityBeijing 102206China School of Energy and Power Engineering Beihang UniversityBeijing 102206China Key Laboratory of Fluid and Power Machinery Ministry of EducationXihua UniversityChengdu 610039China

Partial surge is a type of instability inception discovered in our previous *** has been confirmed that partial surge is localized in the blade hub region,and the flow oscillation it caused will lead to the stall cells in the rotor *** since all information about partial surge is obtained from the compressor stage experiments,what will happen to the stall process after the stators are removed is also an issue that worth ***,in this paper,a series of experiments are carried out on the single rotor embedded in the transonic compressor stage with partial surge ***,the experimental results under uniform inlet conditions show that,although partial surge appears at high rotor speed in the stage case,it does not occur at any speed in the single rotor ***,it is found by numerical simulation that the absence of partial surge may be due to the insufficient rotor hub loading,so an experiment with increased hub loading is carried out,but still fails to trigger partial ***,the reason why partial surge doesn’t occur in the single rotor is *** these results,it can be concluded that partial surge cannot occur in the single rotor case,and the large-scale comer separation in the stator hub is considered to play an important role in the formation of partial surge.

关键词： transonic rotor instability inception partial surge blade loading corner separation

国外大都市圈轨道交通票制票价对京津冀都市圈启示

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西安电子科技大学学报（社会科学版） 2016年第6期26卷 79-84页

作者：潘秋实唐永忠吴嘉琪芮光伟北京交通大学经济管理学院北京100044

发展城际铁路是满足大都市圈交通需求、人员调控、使经济协同发展的有效手段,也是大都市圈实现交通可持续发展的战略举措。然而,城际铁路特殊性决定了合理制定票制票价必须要考虑多种因素。目前京津冀城际铁路处于布局及初步建设阶段,... 详细信息

发展城际铁路是满足大都市圈交通需求、人员调控、使经济协同发展的有效手段,也是大都市圈实现交通可持续发展的战略举措。然而,城际铁路特殊性决定了合理制定票制票价必须要考虑多种因素。目前京津冀城际铁路处于布局及初步建设阶段,研究境内外其他大都市圈城际轨道交通票制票价做法,对于京津冀城际铁路票制票价合理确定有着指导性作用。本文基于对京津冀都市圈特征分析,选择了与京津冀都市圈具有高度相似性的3大首都型世界都市圈:东京大都市圈、伦敦大都市圈和巴黎大都市圈,总结并分析了这些都市圈城际铁路票制票价做法,与京津冀城际铁路票制票价情况进行全面对比,对现行票制票价做出了全面评价,并在境外首都型都市圈城际铁路合理做法的基础上,探索了京津冀城际铁路票制票价的改革思路,提出符合京津冀特征的票制票价改革建议。

关键词：城际铁路大都市圈票制票价启示

Streamwise-body-force-model for rapid simulation combining internal and external flow fields

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Chinese Journal of Aeronautics 2016年第5期29卷 1205-1212页

作者： Cui Rong Li qiushi pan Tianyu Zhang Jian National Key Laboratory on Aero-Engines Beihang University Collaborative Innovation Center of Advanced Aero-Engine Beihang University Department of Engine Project Aviation Industry Corporation of China

A streamwise-body-force-model （SBFM） is developed and applied in the overall flow simulation for the distributed propulsion system, combining internal and external flow fields. In view of axial stage effects, fan or compressor effects could be simplified as body forces along the streamline. These body forces which are functions of local parameters could be added as source terms in Navier-Stokes equations to replace solid boundary conditions of blades and hubs. The val- idation of SBFM with uniform inlet and distortion inlet of compressors shows that pressure performance characteristics agree well with experimental data. A three-dimensional simulation of the integration configuration, via a blended wing body aircraft with a distributed propulsion system using the SBFM, has been completed. Lift coefficient and drag coefficient agree well with wind tunnel test results. Results show that to reach the goal of rapid integrated simulation combining internal and external flow fields, the computational fluid dynamics method based on SBFM is reasonable.

关键词： Aircraft Blended wing body Boundary layer ingestion Distributed propulsion sys-tem Integrated simulations Streamwise-body-force-model

Study on effects of thickness on airfoil-stall at low Reynolds numbers by cusp-catastrophic model based on GA(W)-1 airfoil

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Chinese Journal of Aeronautics 2020年第5期33卷 1444-1453页

作者： Zhiping LI Peng ZHANG Tianyu pan qiushi LI Jian ZHANG National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics Beihang UniversityBeijing 100083China Collaborative Innovation Center for Advanced Aero-Engine Beihang UniversityBeijing 100083China School of Energy and Power Engineering Beihang UniversityBeijing 100083China Key Laboratory of Fluid and Power Machinery Ministry of EducationXihua UniversityChengdu 610039China

The phenomena of an airfoil stall present the behaviors of catastrophe and hysteresis at low Reynolds *** simulation results of two-dimensional airfoil GA(W)-1 show that the width of the hysteresis loop of airfoil stall will gradually decrease and even disappear with the decrease of thickness *** nonlinear characteristics are in accordance with the topological features of the cusp catastrophic *** to the topological invariant principle,a novel topological mapping method is developed to establish the mapping relationship between cusp catastrophic model and stall characteristics of the airfoil,then the effect of thickness ratio on airfoil stall is successfully described quantitatively by cusp catastrophic ***,based on the established topological mapping relationship,combined with the mean flow field of the airfoil stall,potential function approach of cusp catastrophic model is first introduced to interpret the catastrophe and hysteresis of the airfoil stall,and it is found that as the thickness ratio decreases,the system’s maximal potential energy gradually disappears,and the short separation bubble at the leading edge of the airfoil changes to long separation bubble,so the airfoil stall changes from a bistable system to a monostable system.

关键词： Airfoil Catastrophe theory Low Reynolds number Potential function Thickness ratio

Hysteresis behaviors of compressor rotating stall with cusp catastrophic model

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Chinese Journal of Aeronautics 2018年第5期31卷 1075-1084页

作者： Zhiping LI Peng ZHANG Tianyu pan qiushi LI Jian ZHANG National Key Laboratory of Science and Technology on Aero-Engine Aerothermodynamics Beihang University Collaborative Innovation Center of Advanced Aero-Engine Beihang University School of Energy and Power Engineering Beihang University Department of Mechanical Engineering and Materials Science Duke University

Rotating stall is a complex nonlinear dynamic phenomenon which is always characterized by catastrophe and hysteresis in high aerodynamic-loading compressor. Exploring the key contributing factors and characteristic rules of hysteresis is very important for compressor design and flow instability control. In this paper, a novel model method is proposed to analyze the hysteresis behaviors to extend the understanding of compressor rotating stall. The equilibrium states of compressor system under different conditions are first described based on Moore-Greitzer model. Then,through assessing the stability of the equilibrium points by Liapunov＇s theorem, the ratio of shutoff head to compressor characteristic semi-height is found to affect the stall hysteresis： the size of hysteresis loop will gradually decrease, even disappear with the increase of the ratio. Combing the effects of both the ratio and throttle coefficient, the hysteresis behaviors of compressor stall under multi-parameters can be found to be consistent with the topological properties of cusp catastrophic model by Thom＇s catastrophe theory. Finally, according to topological invariant rules, from the perspective of potential function, the equilibrium surface equation of compressor system is developed by standard cusp catastrophic model to describe the various hysteresis behaviors of compressor rotating stall along different control routes.

关键词： Catastrophe theory Compressor Hysteresis Rotating stall Topological analysis

Effect of system response on partial surge initiated instability in a transonic axial flow compressor

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Chinese Journal of Aeronautics 2022年第2期35卷 117-127页

作者： Tianyu pan Zhaoqi YAN Dakun SUN Simin LI Mengzong ZHENG qiushi LI Reserach Institute of Aero-Engine Beihang UniversityBeijing 100083China School of Energy and Power Engineering Beihang UniversityBeijing 100083China Key Laboratory of Fluid and Power Machinery Ministry of EducationXihua UniversityChengdu 610039China

Partial surge is a type of instability inception in transonic compressors and occurs in the form of axisymmetric low-frequency disturbances localized in the hub *** studies illustrate that the frequency of partial surge is set by the Helmholtz frequency of the entire system,which motivates to propose a hypothesis that the system response performs an important role in the formation of partial *** further verification,a series of experiments are conducted to explore the link between the propagating of the partial surge and the system feedback in this *** the first case,an additional test point is set on the wall of the plenum to detect the system *** the flow behaviors inside the plenum with the disturbances in the rotor tip and stator hub/tip regions,the effects of the system feedback on the occurrence of the continuous disturbances and the rotating stall cells are *** the second case,a screen is mounted at the compressor outlet to prevent positive feedback from the *** experimental results demonstrate that in the absence of system feedback,it is the occurrence of spike-type stall inception that leads to the flow instability instead of that of partial *** addition,three flow phenomena in the second case are discussed,including the occurrence of the single pulse,the unstable process during the stall evolution and the switch of instability inception.

关键词： Partial surge Plenum amplification Rotating stall System response Stall inception Transonic compressor