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Variability of the deep South China Sea circulation derived from HYCOM reanalysis data

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Acta Oceanologica Sinica 2022年第7期41卷 54-64页

作者： Yaohua Zhu Guojiao Cao Yonggang wang Shujiang Li Tengfei Xu dingqi wang Fei Teng Zexun Wei First Institute of Oceanography and Key Laboratory of Marine Science and Numerical ModelingMinistry of Natural ResourcesQingdao266061China Laboratory for Regional Oceanography and Numerical Modeling Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao266237China Shandong Key Laboratory of Marine Science and Numerical Modeling Qingdao266061China Navigation College Jiangsu Maritime InstituteNanjing211100China College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdao266100China

This study aims to investigate variability of the deep South China Sea(SCS)circulation using the Hybrid Coordinate Ocean Model(HYCOM)global reanalysis product.The results reveal that annual cycle is a dominant component in the deep SCS circulation.Meanwhile,the boundary circulation strength is the weakest in January and peaks between June and September.The eastern and southern boundary currents strengthen/weaken one to three months earlier than that in the western and northern boundaries.Vector Empirical Orthogonal Functions(VEOF)analysis results reveal that semiannual and intraseasonal fluctuations are significant components,of which the spatial patterns are mainly confined in the northern and western boundary areas as well as the southwestern sub-basin.Wavelet analysis results show the strength of significant fluctuation varies year to year.Trend analysis results indicate a decadal weakening in the deep SCS circulation.An anomalous anticyclonic circulation,50–70 km apart from the slope break,tends to weaken the cyclonic boundary circulation in the western and northern boundaries as well as the southwestern sub-basin.This trend is similar to the observed decadal weakening in the North Atlantic deep circulation.Thus,the findings of this study reveal that the variation of the deep SCS circulation has a remarkable response to the climate change.The mechanisms responsible for the variation are worth pursuing if more observations are available.

关键词： South China Sea variability of deep circulation HYCOM data VEOF analysis wavelet analysis

Method of Determining Windmill Characteristics of Propeller Engine

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国际设备工程与管理:英文版 2023年第3期28卷 145-165页

作者： wang dingqi LI Mi Power-Plant Flight Test Technology Institute Chinese Flight Test EstablishmentXi′an 710089China

Taking the model for propeller transport aircraft as the research object,according to the transient windmill characteristics in the process of stop feathering and starting in the air,the simulation calculation of different flight heights,blade angles and rotation speeds was carried out,and the transient windmill resistance of the propeller was quantitatively given.The engine torque was calculated by using the simulation model are compared and verified using the flight test data,and the maximum error was 7􀆰4%.In the windmill state,the airflow works on the propeller,and the airflow velocity behind the propeller disk decreases,wrapping the entire nacelle surface.In the process of parking feathering,the blade angle decreases slightly at first,and then increases rapidly under the action of the large⁃pitch oil pressure,and the speed of rotation increases gradually.When the blade angle at 30°,the windmill resistance at-108 kgf.In the process of starting,the propeller speed increases and the propeller resistance increases first and decreases.When the propeller returns to 14°,the transient windmill resistance at-1720 kgf.

关键词： windmill resistance numerical simulation slipstream of propeller air start

Aerodynamic Coupling Analysis of Counter⁃rotating Propfan and Inlet Flow Field

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International Journal of Plant Engineering and Management 2023年第2期28卷 65-85页

作者： wang dingqi GAO Yang The Engine Department Chinese Flight Test EstablishmentXi'an 710089China

Taking a propfan engine as the research object,the CFD method was used for 3D modeling and unsteady slip flow for numerical calculation.The propfan rotation domain and the nacelle outside flow domain were meshed by using the partition splicing grid technology.Used the Reynolds⁃averaged of N⁃S equation,the Reynolds stress term uses the RNG turbulence model;and based on the slip grid method,numerical calculation of the flow field with different Mach numbers,front and rear blade angles and engine state were carried out;and the change law of propeller fan characteristics and the influence of slip flow on the inlet flow field were analyzed.The blade angle was the key parameter of the propeller fan characteristic conditions.When the blade angle increases from 41°to 50°,the thrust coefficient increases by 31.2%,and the power coefficient increases by 33.4%;in the climbing state of the propeller fan,the maximum total pressure distortion at the inlet port of 6.8%;the cross section is less affected by the slip flow of the propfan;and the pressure distribution is relatively uniform,but the area of the flow channel is small.The research results can provide a solution for the matching of the counter⁃rotating propeller fan and the engine and the arrangement of the air inlet measuring rake.

关键词： counter rotor propfan numerical simulation patched⁃grid dynamic characteristic unsteady flow distortion of total pressure

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螺旋桨运输机进气道阻力特性分析

空军工程大学学报 2023年第1期24卷 68-75页

作者：王定奇中国飞行试验研究院动力装置飞行试验技术研究所西安710089

以某型螺旋桨运输机带动力装置飞行试验台为研究对象,建立了三维流场模型,采用CFD进行了网格划分及数值计算。以前期飞行试验数据和发动机热力循环模型计算结果为边界条件,开展了不同飞行马赫数、高度及桨叶角的数值计算。选用桨叶角表... 详细信息

以某型螺旋桨运输机带动力装置飞行试验台为研究对象,建立了三维流场模型,采用CFD进行了网格划分及数值计算。以前期飞行试验数据和发动机热力循环模型计算结果为边界条件,开展了不同飞行马赫数、高度及桨叶角的数值计算。选用桨叶角表征发动机状态,分析了不同飞行高度、马赫数、螺旋滑流对进气道前罩作用力和附加前体力影响的变化规律。计算结果表明:不同高度、桨叶角及马赫数均会改变进气道阻力,在马赫数0.5,高度4 km状态下,桨叶角由40°增大至50°,前罩作用力减小1700 N,附加前体力减小3600 N,而附加前体力系数及前罩作用力系数随飞行高度基本不变。进气道阻力特性研究为后续试飞中确定涡桨发动机外部阻力特性分析提供了数据支持。

关键词：飞行试验台数值计算螺旋桨滑流前罩作用力附加前体力捕获面积比

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螺旋桨瞬态风车阻力确定技术研究

飞行力学 2022年第5期40卷 74-79,94页

作者：王定奇屈霁云中国飞行试验研究院陕西西安710089

针对某螺旋桨停车顺桨和空中起动过程中瞬态风车特性开展仿真计算,定量给出了螺旋桨瞬态风车阻力,并利用风洞试验对仿真结果进行验证。通过对标准螺旋桨效用因子和零升迎角的修正,获取修正后螺旋桨风车特性,利用最小二乘法给出螺旋桨风... 详细信息

针对某螺旋桨停车顺桨和空中起动过程中瞬态风车特性开展仿真计算,定量给出了螺旋桨瞬态风车阻力,并利用风洞试验对仿真结果进行验证。通过对标准螺旋桨效用因子和零升迎角的修正,获取修正后螺旋桨风车特性,利用最小二乘法给出螺旋桨风车特性最优解。研究表明:停车顺桨中桨叶角先略有减小,后迅速增大,转速下降速率逐渐增大;起动回桨过程中螺旋桨转速增大,桨叶角减小,风车阻力先增大后减小,回桨至14°时,瞬态风车阻力达到最大值。所得结果可为涡桨发动机试飞中的风车阻力确定及试验点规划提供技术支撑。

关键词：风车阻力效用因子零升迎角螺旋桨瞬态风车

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分开排气系统特性校准试验研究

实验流体力学 2023年第6期37卷 61-69页

作者：李秋锋李密高翔王定奇中国飞行试验研究院西安710089

飞行试验时,采用燃气发生器法间接获取航空发动机飞行推力。为提高飞行推力计算精度,需准确获取航空发动机排气系统特性。采用某大涵道比分开排气系统缩比模型开展了实验室校准箱吹风试验及数值模拟研究,结果表明:采用实验室校准箱吹风... 详细信息

飞行试验时,采用燃气发生器法间接获取航空发动机飞行推力。为提高飞行推力计算精度,需准确获取航空发动机排气系统特性。采用某大涵道比分开排气系统缩比模型开展了实验室校准箱吹风试验及数值模拟研究,结果表明:采用实验室校准箱吹风试验、数值模拟获取的单独内涵喷管特性趋势一致、数值接近,最大内涵喷管压比为1.44时,喷管流量和推力偏差分别为0.73%、0.18%;通过试验和数值模拟获取的内外涵分开排气系统特性趋势一致、数值接近,最大外涵喷管压比为1.46时,喷管流量和推力偏差分别为0.64%、0.18%;对大涵道比分开排气系统物理模型与几何模型进行合理简化后,试验和数值模拟获取的分开排气系统特性偏差满足工程精度要求。

关键词：排气系统喷管特性校准大涵道比

发动机进排气系统对飞机气动特性影响的数值研究

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航空动力学报 2020年第5期35卷 1000-1008页

作者：高翔李密王定奇中国航空工业集团有限公司中国飞行试验研究院发动机所西安710089

为了分析发动机与飞机系统耦合过程中产生的气动力特性,准确获取实际使用条件下的飞机升阻特性,以带动力的某半模飞机模型为研究对象,开展了三维流场数值仿真计算,利用风洞试验数据对计算方法进行了验证,总结了溢流阻力及排气干扰阻力... 详细信息

为了分析发动机与飞机系统耦合过程中产生的气动力特性,准确获取实际使用条件下的飞机升阻特性,以带动力的某半模飞机模型为研究对象,开展了三维流场数值仿真计算,利用风洞试验数据对计算方法进行了验证,总结了溢流阻力及排气干扰阻力的变化规律,结果表明:发动机状态变化对飞机升阻特性影响明显,在选定的发动机工作参考状态下,溢流阻力在飞机系统升力与阻力方向的分量随捕获面积比的增大分别增大、减小,排气系统实际工作状态偏离选定的参考状态越远,干扰阻力在飞机系统升力和阻力方向分量的绝对值越大。

关键词：升阻特性风洞试验溢流阻力排气干扰阻力捕获面积比

Assessment of tree-ring mercury radial translocation and age effect in Masson pine:Implications for historical atmospheric mercury reconstruction

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Journal of Environmental Sciences 2024年第4期138卷 266-276页

作者： Xu Liu Xun wang Dingyong wang College of Resources and Environment Southwest UniversityChongqing 400715China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China

The tree ring has been regarded as an emerging archive to reconstruct historical atmospheric mercury(Hg)trends,but with the large knowledge gaps in the reliability.In this study,we comprehensively evaluated the Hg source,radial translocation and age effect of Masson pine(Pinus massoniana)tree ring at Mt.Jinyun in Chongqing,to assess the suitability of such tree ring as the archive of atmospheric Hg.Results showed that distinct variabilities among Masson pine tree-ring Hg concentration profiles.The Hg concentration significantly increased along with stem height(P<0.05),indicating the Hg in tree rings mainly derived from foliage uptake atmospheric Hg.We found a distinct age effect that the tree ring of young trees had the higher Hg concentration.Besides,we used the advection-diffusion model to demonstrate how Hg concentration shifted by the advection or/and diffusion in tree rings.The modeling results showed that the advection induced radial translocation during the young growth period of tree was a plausible mechanism to result in the tree-ring Hg record largely different from the trend of anthropogenic Hg emissions in Chongqing.We finally suggest that in further Hg dendrochemistry,better discarding the tree-ring Hg profile of the young growth period to reduce impacts of the radial translocation and age effect.

关键词： Masson pine Tree-ring mercury Radial translocation Tree age effect

Pushing the boundaries: an interview with Dae-Hyun Kim on terahertz devices

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National Science Review 2024年第3期11卷 42-45页

作者： Defu wang the Center for Carbon-based Electronics School of Electronics Peking University

Ⅲ–Ⅴ compound semiconductors, such as InGaAs/InAlAs, exhibit exceptional carrier transport properties, establishing them as fundamental elements in terahertz(THz) applications crucial for the development of 6G netwo...

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