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Prediction of separation flows around a 6:1 prolate spheroid using RANS/LES hybrid approaches

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Acta Mechanica Sinica 2007年第4期23卷 369-382页

作者： Zhixiang Xiao Yufei Zhang Jingbo huang haixin {2. song fu school of aerospace Engineering,tsinghua university,beijing 100084,China school of aerospace Engineering Tsinghua University

This paper presents hybrid Reynolds-averaged Navier-Stokes （RANS） and large-eddy-simulation （LES） methods for the separated flows at high angles of attack around a 6：1 prolate spheroid. The RANS/LES hybrid meth- ods studied in this work include the detached eddy simulation （DES） based on Spalart-Allmaras （S-A）, Menter＇s k-ω shear-stress-transport （SST） and k-o9 with weakly nonlinear eddy viscosity formulation （Wilcox-Durbin＋, WD＋） models and the zonalANS/LES methods based on the SST and WD＋ models. The switch from RANS near the wall to LES in the core flow region is smooth through the implementation of a flow-dependent blending function for the zonal hybrid method. All the hybrid methods are designed to have a RANS mode for the attached flows and have a LES behavior for the separated flows. The main objective of this paper is to apply the hybrid methods for the high Reynolds number separated flows around prolate spheroid at high-incidences. A fourth-order central scheme with fourth-order artificial viscosity is applied for spatial differencing. The fully implicit lower-upper symmetric-Gauss-Seidel with pseudo time sub-iteration is taken as the temporal differentiation. Comparisons with available measurements are carried out for pressure distribution, skin friction, and profiles of velocity, etc. Reasonable agreement with the experiments, accounting for the effect on grids and fundamental turbulence models, is obtained for the separation flows.

关键词： RANS/LES hybrid methods DES Zonal-RANS/LES Weakly nonlinear correction

Study of control effects of vortex generators on a supercritical wing

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Science China(Technological Sciences) 2010年第8期53卷 2038-2048页

作者： huang JingBo 1 ,XIAO ZhiXiang 1 ,fu {2. 1 &ZHANG Miao 2.1 {2. of aerospace Engineering,tsinghua university,beijing 100084,China 2.Shanghai Aircraft Design and Research Institute of COMAC,Shanghai 2.02.2.China school of aerospace Engineering Tsinghua University Shanghai Aircraft Design and Research Institute of COMAC

Flows around vortex generators(VGs),which serve as one of the important flow control methods,are investigated by solving Reynolds-averaged Navier-Stokes(RANS)*** influences on the main flow of VGs are intended to ***, the flow around a single VG on a flat plane is computed to validate the schemes and to acquire basic knowledge of this kind of ***,transonic flow past a standard model,named by ONERA-M6 wing,is predicted to investigate the flow features of shockwave/boundary-layer interactions(SWBLI).Thirdly,the effects of a row of VGs mounted about 2.%local chord on a supercritical wing are analyzed in transonic condition with strong ***,VGs are mounted more upwind(about 3.5%local chord)to explore the effects at low speed and high incidence *** numerical results show that seven VGs can effectively suppress the separations behind the strong SWBLI and decrease spanwise flow and wing-tip vortex in transonic *** also can decrease the large scope of separation over the wing at low speed with high angle of attack.

关键词： supercritical wing vortex generator(VG) shockwave/boundary-layer interactions(SWBLI)

Identification of vortices in a transonic compressor flow and the stall process

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航空动力学报 2007年第9期22卷 1455-1460页

作者： huang Xu-dong,chen Hai-xin,{2. {2.,David Wisler,Aspi Wadia,G.Scott McNulty(school of aerospace,tsinghua university,beijing 100084 GE Aircraft Engines,Mail Drop A411,One Neumann Way,Cincinnati,OH 452.5,USA) school of aerospace Tsinghua University Beijing 100084 school of aerospace Tsinghua University Beijing GE Aircraft Engines Mail Drop A411 One Neumann Way Cincinnati USA

A novel vortex identification method for the visualization of the flow field is used for the study of the stall process of a transonic *** parameter η4,which is one of the five invariants formed by the stain rate and vorticity tensors from the theory of modern rational mechanics,is found to have good ability to identify vortex stretching and vortex relaxation/breakdown processes,is introduced here to identify the tip leakage *** with former generally used DPH(dynamic pressure head) contour,the new method reveals much more flow details which may advance our understanding of the compressor *** Vortices details are revealed in both peak efficiency and near stall condition.A possible stall process is also suggested based on the vortices *** tip leakage flow from mid-chord,besides leading edge leakage flow,is also considered to play an important role in the stall process.

关键词：旋涡鉴别跨音速压气机涡动性张量现代理性力学

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相场模拟研究AZ31B镁合金的动态再结晶

高压物理学报 2024年第3期38卷 49-58页

作者：许可盛杰刘瑜黄厚兵施小明宋海峰北京理工大学材料学院北京100081 北京理工大学前沿交叉科学研究院北京100081 北京应用物理与计算数学研究所计算物理全国重点实验室北京100094 北京科技大学数理学院北京100083

镁合金被广泛应用于材料科学、航空航天及军事装备等领域。实验发现,镁合金材料在动态加载下的力学响应与介观尺度不连续动态再结晶紧密相关。为此,构建了镁合金动态再结晶的相场模型,以AZ31B镁合金为研究对象,模拟了不同温度(2.0~400℃... 详细信息

镁合金被广泛应用于材料科学、航空航天及军事装备等领域。实验发现,镁合金材料在动态加载下的力学响应与介观尺度不连续动态再结晶紧密相关。为此,构建了镁合金动态再结晶的相场模型,以AZ31B镁合金为研究对象,模拟了不同温度(2.0~400℃)、低应变率(0.01~1.00 s^(-1))加载下的不连续动态再结晶演化过程。再结晶相场模型耦合了塑性应变,实现了应力-应变曲线与再结晶组织演化的迭代求解。模拟发现,再结晶晶粒的体积分数和平均晶粒尺寸随温度的升高而明显增大,随应变率的增大而减小。

关键词：相场模拟镁合金动态再结晶力学响应

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Simulation of shock wave buffet and its suppression on an OAT15A supercritical airfoil by IDDES

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Science China(Physics,Mechanics & Astronomy) 2012年第2期55卷 260-271页

作者： huang JingBo XIAO ZhiXiang LIU Jian fu {2. school of aerospace Engineering Tsinghua UniversityBeijing 100084China China Aerodynamics Research&Development Center Mianyang 621000China

In the present paper,extremely unsteady shock wave buffet induced by strong shock wave/boundary-layer interactions (SWBLI) on the upper surface of an OAT15A supercritical airfoil at Mach number of 0.73 and angle of attack of 3.5 degrees is first numerically simulated by IDDES,one of the most advanced RANS/LES hybrid *** results imply that conventional URANS methods are unable to effectively predict the buffet phenomenon on the wing surface;IDDES,which involves more flow physics,predicted buffet *** complex flow phenomena are predicted and demonstrated,such as periodical oscillations of shock wave in the streamwise direction,strong shear layer detached from the shock wave due to SWBLI and plenty of small scale structures broken down by the shear layer instability and in the *** root mean square (RMS) of fluctuating pressure coefficients and streamwise range of shock wave oscillation reasonably agree with experimental ***,two vortex generators (VG) both with an inclination angle of 30 degrees to the main flow directions are mounted in front of the shock wave region on the upper surface to suppress shock wave *** results show that shock wave buffet can be significantly suppressed by VGs,the RMS level of pressure in the buffet region is effectively reduced,and averaged shock wave position is obviously pushed downstream,resulting in increased total lift.

关键词： supercritical airfoil vortex generator shock wave buffet

Incidence and prognosis of olfactory and gustatory dysfunctions related to SARS-CoV-2.Omicron strain infection in China:A national multicenter survey of 35,566 individuals

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World Journal of Otorhinolaryngology-Head and Neck Surgery 2024年第2期10卷 113-120页

作者： Meng-Fan Liu Rui-Xia Ma Xian-Bao Cao Hua Zhang Shui-Hong Zhou Wei-Hong Jiang Yan Jiang Jing-Wu Sun Qin-Tai Yang Xue-Zhong Li Ya-Nan Sun Li shi Min Wang Xi-cheng {2. fu-Quan chen Xiao-Shu Zhang Hong-Quan Wei Shao-Qing Yu Dong-Dong Zhu Luo Ba Zhi-Wei Cao Xu-Ping Xiao Xin Wei Zhi-Hong Lin Feng-Hong chen Chun-Guang Shan Guang-ke Wang Jing Ye Shen-Hong Qu Chang-Qing Zhao Zhen-Lin Wang Hua-Bin Li Feng Liu Xiao-Bo Cui Sheng-Nan Ye Zheng Liu Yu Xu Xiao Cai Wei huang Ru-Xin Zhang Yu-Lin Zhao Guo-Dong Yu Guang-Gang shi Mei-Ping Lu Yang Shen Yu-Tong Zhao Jia-Hong Pei Shao-Bing Xie Long-Gang Yu Ye-Hai Liu Shao-Wei Gu Yu-cheng Yang Lei cheng Jian-Feng liu Graduate school of beijing {2. of Chinese Medicine BeijingChina Department of Otorhinolaryngology Head and Neck Surgery China-Japan Friendship HospitalBeijingChina Department of Otorhinolaryngology Head and Neck Surgery The First People's Hospital of YinchuanYinchuanChina Department of Otorhinolaryngology The First People's Hospital of Yunnan ProvinceKunmingChina Department of Otorhinolaryngology The First Affiliated Hospital of Xinjiang Medical UniversityUrumqiChina Department of Otorhinolaryngology Head and Neck Surgery The First Affiliated Hospital of Zhejiang University School of MedicineHangzhouChina Department of Otorhinolaryngology Head and Neck Surgery Xiangya Hospital Central South UniversityChangshaChina Department of Otorhinolaryngology Head and Neck Surgery The Affiliated Hospital of Qingdao UniversityQingdaoChina Department of Otorhinolaryngology Head and Neck Surgery The First Affiliated Hospital of USTCHefeiChina Department of Otorhinolaryngology Head and Neck Surgery The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhouChina Department of Otorhinolaryngology Head and Neck Surgery Qilu Hospital of Shandong UniversityJinanChina Department of Otorhinolaryngology Head and Neck Surgery The Second Affiliated Hospital of Harbin Medical UniversityHarbinChina Department of Otolaryngology The Second Hospital of Shandong UniversityShandong UniversityJinanChina Department of Otorhinolaryngology Head and Neck Surgery Peking University People's HospitalBeijingChina Department of Otorhinolaryngology Head and Neck Surgery Yantai Yuhuangding HospitalQingdao UniversityYantaiChina Department of Otorhinolaryngology Head and Neck Surgery Xijing HospitalThe Fourth Military Medical UniversityXi'anChina Gansu Provincial Center for Disease Control and Prevention LanzhouChina Department of Otorhinolaryngology Head and Neck Surgery The First Affiliated Hospital of China Medical UniversityShenyangChina Department of Otorhinolaryngology Head and Neck Surgery Tongji Hospit

Objective:This cross-sectional study aimed to determine the epidemiology of olfactory and gustatory dysfunctions related to COVID-19 in ***:This study was conducted by 45 tertiary Grade-A hospitals in *** and offline questionnaire data were obtained from patients infected with COVID-19 between December 2.,2.2.,and February 2.,*** collected information included basic demographics,medical history,smoking and drinking history,vaccination history,changes in olfactory and gustatory functions before and after infection,and other postinfection symptoms,as well as the duration and improvement status of olfactory and gustatory ***:Complete questionnaires were obtained from 35,566 *** overall incidence of olfactory and taste dysfunction was 67.75%.Being female or being a cigarette smoker increased the likelihood of developing olfactory and taste *** received four doses of the vaccine or having good oral health or being a alcohol drinker decreased the risk of such *** infection,the average olfactory and taste VAS scores were 8.41 and 8.51,respectively;after infection,they decreased to 3.69 and 4.2. and recovered to 5.83 and 6.55 by the time of the *** median duration of dysosmia and dysgeusia was 15 and 12.days,respectively,with 0.5%of patients having symptoms lasting for more than 2. *** overall self-reported improvement rate was 59.16%.Recovery was higher in males,never smokers,those who received two or three vaccine doses,and those that had never experienced dental health issues,or chronic accompanying ***:The incidence of dysosmia and dysgeusia following infection with the SARS-CoV-2.virus is high in *** and prognosis are influenced by several factors,including sex,SARS-CoV-2.vaccination,history of head-facial trauma,nasal and oral health status,smoking and drinking history,and the persistence of accompanying symptoms.

关键词： epidemiologic studies incidence olfactory disorders prognosis SARS-CoV-2 taste disorders

Occurrence, variations, and risk assessment of neonicotinoid insecticides in Harbin section of the songhua River, northeast China

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Environmental Science and Ecotechnology 2021年第4期8卷 85-93页

作者： Zhikun Liu song Cui Leiming Zhang Zulin Zhang Rupert Hough Qiang fu Yi-Fan Li Lihui An Mingzhi {2. Kunyang Li Yuxin ke fuxiang Zhang International Joint Research Center for Persistent Toxic Substances(IJRC-PTS) School of Water Conservancy and Civil EngineeringNortheast Agricultural UniversityHarbinHeilongjiang150030China Research Center for Eco-Environment Protection of songhua River Basin Northeast Agricultural UniversityHarbinHeilongjiang 150030China Air Quality Research Division Science and Technology BranchEnvironment and Climate Change CanadaTorontoOntarioM3H 5T4Canada The James Hutton Institute CraigiebucklerAberdeenAB158QHUK State Environmental Protection key Laboratory of Estuarine and Coastal Research Chinese Research Academy of Environmental SciencesBeijing100012China school of Environment South China Normal UniversityGuangzhou510006China

Neonicotinoid insecticides(NNIs)have been intensively used and exploited,resulting in their presence and accumulation in multiple environmental *** herein investigated the current levels of eight major NNIs in the Harbin section of the songhua River in northeast China,providing the first systematic report on NNIs in this *** least four NNIs in water and three in sediment were detected,with total concentrations ranging from 30.8 to 135 ng L^(-1) and from 0.61 to 14.7 ng g^(-1) dw,*** spatial variations in surface water NNIs concentrations were observed in tributary than mainstream(pke(SIMIeq EDI):31.9 ng kg^(-1) bw$d^(-1)).The concentration thresholds of NNIs for aquatic organisms in the Harbin section of the songhua River were determined using the species sensitivity distribution(SSD)approach,resulting in a value of 355 ng L^(-1) for acute hazardous concentration for 5%of species(HC5)and 165 ng L^(-1) for chronic *** organisms at low trophic levels were more vulnerable to potential harm from NNIs.

关键词： Neonicotinoid insecticides Sediment-water exchange Human exposure Species sensitivity distribution

Expert consensus of Chinese Association for the Study of Pain on the non-opioid analgesics for chronic musculoskeletal pain

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World Journal of Clinical Cases 2021年第9期9卷 2068-2076页

作者： Dong huang Yan-Qing Liu Ling-Jie Xia Xian-Guo Liu ke Ma Guang-Zhao Liu Li-Zu Xiao Tao {2. Xiao-Qiu Yang Zhi-Jian fu Min Yan Department of Algology Third Xiangya Hospital of Central South UniversityChangsha 410013Hunan ProvinceChina Department of Algology Beijing Tiantan HospitalCapital Medicine UniversityBeijing 100070China Department of Algology Henan Provincial People's HospitalZhengzhou 450008Henan ProvinceChina Department of Physiology and Pain Research Center Sun Yat-Sen UniversityGuangzhou 510089Guangdong ProvinceChina Department of Algology Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghai 200092China Department of Algology The Second Hospital of Hebei Medical UniversityShijiazhuang 050000Hebei ProvinceChina Department of Algology Huazhong University of Science and Technology Union Shenzhen HospitalShenzhen 518052Guangdong ProvinceChina Department of Algology First Affiliated Hospital of China Medical UniversityShenyang 110001Liaoning ProvinceChina Department of Algology First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China Department of Algology Shandong Provincial HospitalJinan 250021Shandong ProvinceChina Department of Algology The Second Affiliated Hospital of Zhejiang University School of MedicineHangzhou 310009Zhejiang ProvinceChina

Chronic musculoskeletal pain(CMP)is a common occurrence in clinical practice and there are a variety of options for the treatment of ***,the pharmacological therapy is still considered to be a primary *** recent years have witnessed the emergence of opioid crisis,yet there are no relevant guidelines on how to treat CMP with non-opioid analgesics *** Chinese Medical Association for the Study of Pain convened a panel meeting to develop clinical practice consensus for the treatment of CMP with non-opioid *** purpose of this consensus is to present the application of nonsteroidal antiinflammatory drugs,serotonin norepinephrine reuptake inhibitors,serotonin and norepinephrine reuptake inhibitors,muscle relaxants,ion channel drugs and topical drugs in CMP.

关键词： Chronic musculoskeletal pain Non-opioid analgesics Nonsteroidal antiinflammatory drugs Noradrenaline reuptake inhibitor Nociceptor Cyclooxygenase

On the tip sharpness of riblets for turbulent drag reduction

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Acta Mechanica Sinica 2022年第4期38卷 39-55,I0001页

作者： Yiqian Wang Yi huang song {2. school of Mathematical Sciences Soochow UniversitySuzhou 215006China school of aerospace Engineering Tsinghua UniversityBeijing 100084China

It is commonly known that riblets with sharper tip generally have better turbulent drag reduction capacity,which,however,poses great challenges for manufacturing and makes the riblets vulnerable to tip *** this study,we show that a scalloped riblet which is not as sharp in the tip as corresponding triangular riblet with same height-width ratio,nevertheless has a larger protrusion height,a quantity solely depending on the riblet shape and calculated through a boundary element algorithm in this study,and thus a higher projected drag reduction *** addition,it is found that,when subjected to tip rounding,this scalloped riblet performs better in terms of protrusion height than corresponding parabolic riblet,which indicates stronger resilience to riblet tip *** the class of scalloped riblets,designed by smoothly connecting two third-order polynomials and thus the tip sharpness and valley curvature can be well defined,it is revealed that two mechanisms,one for the valley curvature at the viscous limit and one for the tip sharpness at infinite deep limit,determine the protrusion height,and thus the projected drag reduction *** numerical simulations are then carried out to investigate controlled boundary layer transition with the scalloped riblet of width s+=2. and 5+=60.A 7.8%drag reduction in the turbulent region is found for the smaller riblet with a preferable transition delay,while for the larger riblet transition is promoted and drag is increased in the turbulent *** is also found that the area fraction of high drag region around the riblet tips is basically the same for the two ***,even higher drag is found around the tip region for the smaller drag-reducing *** the other hand,a much smaller drag coefficient is found in the valley of the smaller riblet,which results in the reduction of turbulent *** is thus inferred that the issue of sharp riblet tip,that hard to manufacture and deteriorate substantially

关键词： Riblet Turbulent drag reduction Tip sharpness Protrusion height Direct numerical simulation