Performance prediction for centrifugal pumps is now mainly based on numerical calculation and most of the studies merely focus on one model. Therefore, the research results are not representative. To make an improveme...Performance prediction for centrifugal pumps is now mainly based on numerical calculation and most of the studies merely focus on one model. Therefore, the research results are not representative. To make an improvement of numerical calculation method and performance prediction for centrifugal pumps, performance of six centrifugal pump models at design flow rate and off design flow rates, whose specific speed are different, were simulated by using commercial code FLUENT. The standard k-t turbulence model and SIMPLEC algorithm were chosen in FLUENT. The simulation was steady and moving reference frame was used to consider the impeller-volute interaction. Also, how to dispose the gap between impeller and volute was presented and the effect of grid number was considered. The characteristic prediction model for centrifugal pumps is established according to the simulation results. The head and efficiency of the six models at different flow rates are predicted and the prediction results are compared with the experiment results in detail. The comparison indicates that the precision of head and efficiency prediction are all less than 5%. The flow analysis indicates that flow change has an important effect on the location and area of low pressure region behind the blade inlet and the direction of velocity at impeller inlet. The study shows that using FLUENT simulation results to predict performance of centrifugal pumps is feasible and accurate. The method can be applied in engineering practice.展开更多
Retrogressive landslides are common geological phenomena in mountainous areas and on onshore and offshore slopes. The impact of retrogressive landslides is different from that of other landslide types due to the pheno...Retrogressive landslides are common geological phenomena in mountainous areas and on onshore and offshore slopes. The impact of retrogressive landslides is different from that of other landslide types due to the phenomenon of retrogression. The hazards caused by retrogressive landslides may be increased because retrogressive landslides usually affect housing, facilities, and infrastructure located far from the original slopes. Additionally, substantial geomorphic evidence shows that the abundant supply of loose sediment in the source area of a debris flow is usually provided by retrogressive landslides that are triggered by the undercutting of water. Moreover, according to historic case studies, some large landslides are the evolution result of retrogressive landslides. Hence the ability to understand and predict the evolution of retrogressive landslides is crucial for the purpose of hazard mitigation. This paper discusses the phenomenon of a retrogressive landslide by using a model experiment and suggests a reasonably simplified numerical approach for the prediction of rainfall-induced retrogressive landslides. The simplified numerical approach, which combines the finite element method for seepage analysis, the shear strength reduction finite element method, and the analysis criterion for the retrogression and accumulation effect, is presented and used to predict the characteristics of a retrogressive landslide. The results show that this numerical approach is capable of reasonably predicting the characteristics of retrogressive landslides under rainfall infiltration, particularly the magnitude of each landslide, the position of the slip surface, and the development processes of the retrogressive landslide. Therefore, this approach is expected to be a practical method for the mitigation of damage caused by rainfall-induced retrogressive landslides.展开更多
A three-dimensional turbulent flow through an entire centrifugal pump is simulated using k-ε turbulence model modified by rotation and curvature, SIMPLEC method and body-fitted coordinate. The velocity and pressure f...A three-dimensional turbulent flow through an entire centrifugal pump is simulated using k-ε turbulence model modified by rotation and curvature, SIMPLEC method and body-fitted coordinate. The velocity and pressure fields are obtained for the pump under various working conditions, which is used to predict the head and hydraulic efficiency of the pump, and the results correspond well with the measured values. The calculation results indicate that the pressure is higher on the pressure side than that on the suction side of the blade; The relative velocity on the suction side gradually decreases from the impeller inlet to the outlet, while increases on the pressure side, it finally results in the lower relative velocity on the suction side and the higher one on the pressure side at the impeller outlet; The impeller flow field is asymmetric, i.e. the velocity and pressure fields arc totally different among all channels in the impeller; In the volute, the static pressure gradually increases with the flow route, and a large pressure gratitude occurs in the tongue; Secondary flow exists in the rear part of the spiral.展开更多
Ensemble prediction experiments of the tracks of eight tropical cyclones occurring between 2004-2006 over the western Pacific have been performed by using MM5 with five cumulus parameterization schemes. The results sh...Ensemble prediction experiments of the tracks of eight tropical cyclones occurring between 2004-2006 over the western Pacific have been performed by using MM5 with five cumulus parameterization schemes. The results show that the predictions of the tracks of the tropical cyclones are sensitive to the selection of cumulus parameterization schemes. Each scheme has its own advantage and disadvantage, and the predications without cumulus parameterization schemes are not the worst, sometimes even better than the others. And all of the three ensemble methods improve the predictions of the tracks significantly, among which the ensemble method without parameterization schemes, the Grell, Betts-Miller and Kain-Fritsch schemes are the best.展开更多
As an important branch of information technology, high-performance computing has expanded its application field and its influence has been expanding. High-performance computing is always a key area of application in m...As an important branch of information technology, high-performance computing has expanded its application field and its influence has been expanding. High-performance computing is always a key area of application in meteorology. We used field research and literature review methods to study the application of high performance computing in China’s meteorological department, and obtained the following results: 1) China Meteorological Department gradually established the first high-performance computer system since 1978. High-performance computing services can support operational numerical weather prediction models. 2) The Chinese meteorological department has always used the relatively advanced high-performance computing technology, and the business system capability has been continuously improved. The computing power has become an important symbol of the level of meteorological modernization. 3) High-performance computing technology and meteorological numerical forecasting applications are increasingly integrated, and continue to innovate and develop. 4) In the future, high-performance computing resource management will gradually transit from the current local pre-allocation mode to the local remote unified scheduling and shared use. In summary, we have come to the conclusion that the performance calculation business of the meteorological department will usher in a better tomorrow.展开更多
根据超临界二氧化碳(supercritical carbon dioxide,SCO_(2))的物性特点,调用美国国家标准技术研究所(national institute of standards and technology,NIST)发布的二氧化碳物性参数,开发了SCO_(2)离心压缩机一维设计及性能预测的程序...根据超临界二氧化碳(supercritical carbon dioxide,SCO_(2))的物性特点,调用美国国家标准技术研究所(national institute of standards and technology,NIST)发布的二氧化碳物性参数,开发了SCO_(2)离心压缩机一维设计及性能预测的程序。利用该程序完成了-10 MW SCO_(2)布雷顿循环发电系统中的分流压缩机气动设计以及不同转速下的性能预测,并结合数值计算与流场分析,结果表明:在设计转速下,一维预测结果与三维数值模拟所得的压气机性能结果在小流量区域变化趋势与数值大小吻合较好,但是在堵塞工况点附近两者存在一定的偏差。在其他转速下,一维预测结果与三维数值模拟所得的压气机性能结果吻合较好,表明该一维性能预测能较好预测SCO_(2)离心压缩机的变工况运行特性。展开更多
水面起飞性能是水面飞行器的基本性能,也是总体技术的核心,涉及多个学科领域。水陆两栖飞机水面高速滑行水动力性能与排水型船不同,具有速度高、运动复杂等特点,高速滑行时一方面受到较大的水动升力,另一方面受到机翼的升力。结合水陆...水面起飞性能是水面飞行器的基本性能,也是总体技术的核心,涉及多个学科领域。水陆两栖飞机水面高速滑行水动力性能与排水型船不同,具有速度高、运动复杂等特点,高速滑行时一方面受到较大的水动升力,另一方面受到机翼的升力。结合水陆两栖飞机水面高速滑行特点,利用雷诺平均法(Reynolds average navier-stokes, RANS)数值方法和重叠网格技术对水陆两栖飞机全机模型开展数值仿真模拟,分析了自由液面水气分布、机身底部压力分布特征,并将阻力、姿态和升沉与水池模型试验结果进行对比,验证了数值方法的准确性,为水陆两栖飞机静水滑行水动性能数值预报提供技术基础。展开更多
This paper discusses the performance difference between full-spectrum and channel-selection assimilation scheme of hyperspectral infrared observation, e.g. CrIS</span><span style="font-family:""...This paper discusses the performance difference between full-spectrum and channel-selection assimilation scheme of hyperspectral infrared observation, e.g. CrIS</span><span style="font-family:""> </span><span style="font-family:Verdana;">and IASI, on improving the accuracy of initial condition</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">in numerical weather prediction. To accomplish this, we develop a 3D-Variational data assimilation system whose observation operator is a principal-component based fast radiative transfer model, which equips the direct assimilation of full-channel radiance from hyperspectral infrared sounders with high computational efficiency. This project’s primary goal is to demonstrate that assimilation of infrared observation in a full-channel mode could improve the accuracy of initial condition compared to selected-channel assimilation. Resu</span><span style="font-family:Verdana;">lts show that full-channel assimilation performs better than se</span><span style="font-family:Verdana;">lected-channel assimilation in modifying low and middle troposphere (1000 - 700 hPa, 700 - 400 hPa) temperature and water vapor field, while marginal improvements from temperature and water vapor field could be found over upper troposphere (400 - 100 hPa). This research also proves the feasibility of an alternative path to data assimilation for the full usage of hyperspectral infrared sounding observation in numerical weather prediction.展开更多
往返平飘式探空观测是我国研发的一种新型高空观测技术,除了具备与传统探空观测一致的上升段大气垂直廓线观测能力,同时还增加了平飘段和下降段的大气探测,自动实现了探测廓线的时空加密。利用ERA5再分析资料作为“真值”,利用往返平飘...往返平飘式探空观测是我国研发的一种新型高空观测技术,除了具备与传统探空观测一致的上升段大气垂直廓线观测能力,同时还增加了平飘段和下降段的大气探测,自动实现了探测廓线的时空加密。利用ERA5再分析资料作为“真值”,利用往返平飘式探空模拟仿真系统构造了往返式探空模拟观测,基于CMA-MESO区域模式和3D-Var同化系统进行了观测系统模拟试验(Observing System Simulation Experiments,OSSEs)。数值试验结果表明:相比传统单次上升段探空观测,往返平飘式探空在全国组网的情况下,其增加的下降段模拟探空观测,能够有效提高CMA-MESO的降水预报技巧,不同降水量级的ETS评分提高约2%~5%,同时改进要素场(温、湿场和风场)的预报,改进率约为2%~5%。此外,典型天气个例分析结果表明,增加往返平飘式探空观测能够改善模式初值偏差,从而更准确地模拟降水分布。该文的研究结论为往返平飘式探空的未来科学布局和应用提供了理论支撑。展开更多
This article presents the design of a new implantable axial-flow blood pump. The special feature of the flow channel inside the blood pump is that the blood is driven by a big-small tandem impeller installed in the in...This article presents the design of a new implantable axial-flow blood pump. The special feature of the flow channel inside the blood pump is that the blood is driven by a big-small tandem impeller installed in the inner hole of the cylinder magnet of a brushless direct current motor. The inner hole makes the main flow channel possible, while the gap between the inner end of the stator and the outer end of the cylinder magnet gives the shape of the tributary flow channel. There is no motor magnet inside the main flow channel, therefore, more blood can pass through it. The gap of the tributary flow channel is very small, but the blood flow in it is not blocked. Thus, the efficiency is increased and the volume and weight of blood pump can be reduced greatly. The outer diameter, length and weight of the manufactured implantable axial-flow blood pump are 29.6 mm, 76 mm and 158 g, respectively. The impeller spins at the speed of 9000 rpm and can generate a pressure head of 100 mmHg and a flow rate of 8 L/rain. In an animal experiment, the blood pump has been successfully applied as a Ventricular Assist Device (VAD) in the chest of a small cow. Besides a mathematical model is established to simulate the flow inside an axial-flow blood pump of implantable VAD. The numerical studies on the performance of the implantable axial-flow blood pump are carried out by combining this mathematical model and the Fluent software. The numerical results agree well with those of experiments, with the maximum error less than 10%.展开更多
In an effort to assess the impact of the individual component of meteorological observations (ground-based CPS precipitable water vapor, automatic and conventional meteorological observations) on the torrential rain...In an effort to assess the impact of the individual component of meteorological observations (ground-based CPS precipitable water vapor, automatic and conventional meteorological observations) on the torrential rain event in 4-5 July 2000 in Beijing (with the 24-h accumulated precipitation reaching 240 mm), 24-h observation system experiments are conducted numerically by using the MM5/WRF 3DVAR system and the nonhydrostatic MM5 model. Results indicate that, because the non-conventional GPS observations are directly assimilated into the initial analyses by 3DVAR system, better initial fields and 24-h simulation for the severe precipitation event are achieved than those under the MM5/Litter_R objective analysis scheme. Further analysis also shows that the individual component of meteorological observation network plays their special positive role in the improvement of initial field analysis and forecasting skills. 3DVAR scheme with or without radiosonde and pilot observation has the most significant influence on numerical simulation, and automatic and conventional surface meteorological observations rank second. After acquiring the supplement information from the other meteorological observations, the ground-based GPS precipitable water vapor data can more obviously reflect initial field assimilation and precipitation forecast. By incorporating the groundbased CPS precipitable water vapor data into the 3DVAR analyses at the initial time, the threat scores (TS) with thresholds of 1, 5, 10, and 20 mm are increased by 1%-8% for 6- and 24-h accumulated precipitation observations, respectively. This work gives one helpful example that assesses the impact of individual component of the existing meteorological observation network on the high influence weather event using 3DVAR numerical system.展开更多
基金supported by National Outstanding Young Scientists Founds of China (Grant No. 50825902)National Natural Science Foundation of China (Grant No. 50509009)
文摘Performance prediction for centrifugal pumps is now mainly based on numerical calculation and most of the studies merely focus on one model. Therefore, the research results are not representative. To make an improvement of numerical calculation method and performance prediction for centrifugal pumps, performance of six centrifugal pump models at design flow rate and off design flow rates, whose specific speed are different, were simulated by using commercial code FLUENT. The standard k-t turbulence model and SIMPLEC algorithm were chosen in FLUENT. The simulation was steady and moving reference frame was used to consider the impeller-volute interaction. Also, how to dispose the gap between impeller and volute was presented and the effect of grid number was considered. The characteristic prediction model for centrifugal pumps is established according to the simulation results. The head and efficiency of the six models at different flow rates are predicted and the prediction results are compared with the experiment results in detail. The comparison indicates that the precision of head and efficiency prediction are all less than 5%. The flow analysis indicates that flow change has an important effect on the location and area of low pressure region behind the blade inlet and the direction of velocity at impeller inlet. The study shows that using FLUENT simulation results to predict performance of centrifugal pumps is feasible and accurate. The method can be applied in engineering practice.
基金supported by the National Basic Research Program of China(Grant No.2014CB44701)the National Natural Science Foundation of China(NSFC)(Grants No.41272283,40902080,41130753)
文摘Retrogressive landslides are common geological phenomena in mountainous areas and on onshore and offshore slopes. The impact of retrogressive landslides is different from that of other landslide types due to the phenomenon of retrogression. The hazards caused by retrogressive landslides may be increased because retrogressive landslides usually affect housing, facilities, and infrastructure located far from the original slopes. Additionally, substantial geomorphic evidence shows that the abundant supply of loose sediment in the source area of a debris flow is usually provided by retrogressive landslides that are triggered by the undercutting of water. Moreover, according to historic case studies, some large landslides are the evolution result of retrogressive landslides. Hence the ability to understand and predict the evolution of retrogressive landslides is crucial for the purpose of hazard mitigation. This paper discusses the phenomenon of a retrogressive landslide by using a model experiment and suggests a reasonably simplified numerical approach for the prediction of rainfall-induced retrogressive landslides. The simplified numerical approach, which combines the finite element method for seepage analysis, the shear strength reduction finite element method, and the analysis criterion for the retrogression and accumulation effect, is presented and used to predict the characteristics of a retrogressive landslide. The results show that this numerical approach is capable of reasonably predicting the characteristics of retrogressive landslides under rainfall infiltration, particularly the magnitude of each landslide, the position of the slip surface, and the development processes of the retrogressive landslide. Therefore, this approach is expected to be a practical method for the mitigation of damage caused by rainfall-induced retrogressive landslides.
基金This project is supported by Provincial Natural Science Foundation of Jiangsu, China(No.BK2004406)Provincial Innovation Foundation for Graduate Students of Jiangsu, China(No.1223000053
文摘A three-dimensional turbulent flow through an entire centrifugal pump is simulated using k-ε turbulence model modified by rotation and curvature, SIMPLEC method and body-fitted coordinate. The velocity and pressure fields are obtained for the pump under various working conditions, which is used to predict the head and hydraulic efficiency of the pump, and the results correspond well with the measured values. The calculation results indicate that the pressure is higher on the pressure side than that on the suction side of the blade; The relative velocity on the suction side gradually decreases from the impeller inlet to the outlet, while increases on the pressure side, it finally results in the lower relative velocity on the suction side and the higher one on the pressure side at the impeller outlet; The impeller flow field is asymmetric, i.e. the velocity and pressure fields arc totally different among all channels in the impeller; In the volute, the static pressure gradually increases with the flow route, and a large pressure gratitude occurs in the tongue; Secondary flow exists in the rear part of the spiral.
基金Applied Research on Ensemble Forecast Using Multiple Parameterization Schemes, a NaturalScience Foundation project of Zhejiang Province (Y505286)
文摘Ensemble prediction experiments of the tracks of eight tropical cyclones occurring between 2004-2006 over the western Pacific have been performed by using MM5 with five cumulus parameterization schemes. The results show that the predictions of the tracks of the tropical cyclones are sensitive to the selection of cumulus parameterization schemes. Each scheme has its own advantage and disadvantage, and the predications without cumulus parameterization schemes are not the worst, sometimes even better than the others. And all of the three ensemble methods improve the predictions of the tracks significantly, among which the ensemble method without parameterization schemes, the Grell, Betts-Miller and Kain-Fritsch schemes are the best.
文摘As an important branch of information technology, high-performance computing has expanded its application field and its influence has been expanding. High-performance computing is always a key area of application in meteorology. We used field research and literature review methods to study the application of high performance computing in China’s meteorological department, and obtained the following results: 1) China Meteorological Department gradually established the first high-performance computer system since 1978. High-performance computing services can support operational numerical weather prediction models. 2) The Chinese meteorological department has always used the relatively advanced high-performance computing technology, and the business system capability has been continuously improved. The computing power has become an important symbol of the level of meteorological modernization. 3) High-performance computing technology and meteorological numerical forecasting applications are increasingly integrated, and continue to innovate and develop. 4) In the future, high-performance computing resource management will gradually transit from the current local pre-allocation mode to the local remote unified scheduling and shared use. In summary, we have come to the conclusion that the performance calculation business of the meteorological department will usher in a better tomorrow.
文摘根据超临界二氧化碳(supercritical carbon dioxide,SCO_(2))的物性特点,调用美国国家标准技术研究所(national institute of standards and technology,NIST)发布的二氧化碳物性参数,开发了SCO_(2)离心压缩机一维设计及性能预测的程序。利用该程序完成了-10 MW SCO_(2)布雷顿循环发电系统中的分流压缩机气动设计以及不同转速下的性能预测,并结合数值计算与流场分析,结果表明:在设计转速下,一维预测结果与三维数值模拟所得的压气机性能结果在小流量区域变化趋势与数值大小吻合较好,但是在堵塞工况点附近两者存在一定的偏差。在其他转速下,一维预测结果与三维数值模拟所得的压气机性能结果吻合较好,表明该一维性能预测能较好预测SCO_(2)离心压缩机的变工况运行特性。
文摘水面起飞性能是水面飞行器的基本性能,也是总体技术的核心,涉及多个学科领域。水陆两栖飞机水面高速滑行水动力性能与排水型船不同,具有速度高、运动复杂等特点,高速滑行时一方面受到较大的水动升力,另一方面受到机翼的升力。结合水陆两栖飞机水面高速滑行特点,利用雷诺平均法(Reynolds average navier-stokes, RANS)数值方法和重叠网格技术对水陆两栖飞机全机模型开展数值仿真模拟,分析了自由液面水气分布、机身底部压力分布特征,并将阻力、姿态和升沉与水池模型试验结果进行对比,验证了数值方法的准确性,为水陆两栖飞机静水滑行水动性能数值预报提供技术基础。
文摘This paper discusses the performance difference between full-spectrum and channel-selection assimilation scheme of hyperspectral infrared observation, e.g. CrIS</span><span style="font-family:""> </span><span style="font-family:Verdana;">and IASI, on improving the accuracy of initial condition</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">in numerical weather prediction. To accomplish this, we develop a 3D-Variational data assimilation system whose observation operator is a principal-component based fast radiative transfer model, which equips the direct assimilation of full-channel radiance from hyperspectral infrared sounders with high computational efficiency. This project’s primary goal is to demonstrate that assimilation of infrared observation in a full-channel mode could improve the accuracy of initial condition compared to selected-channel assimilation. Resu</span><span style="font-family:Verdana;">lts show that full-channel assimilation performs better than se</span><span style="font-family:Verdana;">lected-channel assimilation in modifying low and middle troposphere (1000 - 700 hPa, 700 - 400 hPa) temperature and water vapor field, while marginal improvements from temperature and water vapor field could be found over upper troposphere (400 - 100 hPa). This research also proves the feasibility of an alternative path to data assimilation for the full usage of hyperspectral infrared sounding observation in numerical weather prediction.
文摘往返平飘式探空观测是我国研发的一种新型高空观测技术,除了具备与传统探空观测一致的上升段大气垂直廓线观测能力,同时还增加了平飘段和下降段的大气探测,自动实现了探测廓线的时空加密。利用ERA5再分析资料作为“真值”,利用往返平飘式探空模拟仿真系统构造了往返式探空模拟观测,基于CMA-MESO区域模式和3D-Var同化系统进行了观测系统模拟试验(Observing System Simulation Experiments,OSSEs)。数值试验结果表明:相比传统单次上升段探空观测,往返平飘式探空在全国组网的情况下,其增加的下降段模拟探空观测,能够有效提高CMA-MESO的降水预报技巧,不同降水量级的ETS评分提高约2%~5%,同时改进要素场(温、湿场和风场)的预报,改进率约为2%~5%。此外,典型天气个例分析结果表明,增加往返平飘式探空观测能够改善模式初值偏差,从而更准确地模拟降水分布。该文的研究结论为往返平飘式探空的未来科学布局和应用提供了理论支撑。
基金supported by the National High Technology Research and Development program of China (863 Program, Grant No. 2007AA02Z439)The Program for Outstanding Medical Academic Leader of Shanghai
文摘This article presents the design of a new implantable axial-flow blood pump. The special feature of the flow channel inside the blood pump is that the blood is driven by a big-small tandem impeller installed in the inner hole of the cylinder magnet of a brushless direct current motor. The inner hole makes the main flow channel possible, while the gap between the inner end of the stator and the outer end of the cylinder magnet gives the shape of the tributary flow channel. There is no motor magnet inside the main flow channel, therefore, more blood can pass through it. The gap of the tributary flow channel is very small, but the blood flow in it is not blocked. Thus, the efficiency is increased and the volume and weight of blood pump can be reduced greatly. The outer diameter, length and weight of the manufactured implantable axial-flow blood pump are 29.6 mm, 76 mm and 158 g, respectively. The impeller spins at the speed of 9000 rpm and can generate a pressure head of 100 mmHg and a flow rate of 8 L/rain. In an animal experiment, the blood pump has been successfully applied as a Ventricular Assist Device (VAD) in the chest of a small cow. Besides a mathematical model is established to simulate the flow inside an axial-flow blood pump of implantable VAD. The numerical studies on the performance of the implantable axial-flow blood pump are carried out by combining this mathematical model and the Fluent software. The numerical results agree well with those of experiments, with the maximum error less than 10%.
基金Supported by project of the Ministry of Science and Technology under Nos.2005DIB3J098,2003DFB00011 and 2002BA904B05,project of the Beijing New Star under No.H013610330119,and projects of Beijing Municipal Science Technology Commission under Nos.H010510120119 and H020620250330,and project of GPS application of Beijing Meteorological Bureau.
文摘In an effort to assess the impact of the individual component of meteorological observations (ground-based CPS precipitable water vapor, automatic and conventional meteorological observations) on the torrential rain event in 4-5 July 2000 in Beijing (with the 24-h accumulated precipitation reaching 240 mm), 24-h observation system experiments are conducted numerically by using the MM5/WRF 3DVAR system and the nonhydrostatic MM5 model. Results indicate that, because the non-conventional GPS observations are directly assimilated into the initial analyses by 3DVAR system, better initial fields and 24-h simulation for the severe precipitation event are achieved than those under the MM5/Litter_R objective analysis scheme. Further analysis also shows that the individual component of meteorological observation network plays their special positive role in the improvement of initial field analysis and forecasting skills. 3DVAR scheme with or without radiosonde and pilot observation has the most significant influence on numerical simulation, and automatic and conventional surface meteorological observations rank second. After acquiring the supplement information from the other meteorological observations, the ground-based GPS precipitable water vapor data can more obviously reflect initial field assimilation and precipitation forecast. By incorporating the groundbased CPS precipitable water vapor data into the 3DVAR analyses at the initial time, the threat scores (TS) with thresholds of 1, 5, 10, and 20 mm are increased by 1%-8% for 6- and 24-h accumulated precipitation observations, respectively. This work gives one helpful example that assesses the impact of individual component of the existing meteorological observation network on the high influence weather event using 3DVAR numerical system.