Wind erosion represents a formidable environmental challenge and has serious negative impacts on soil health and agricultural productivity, particularly in arid and semi-arid areas. The complex dynamics of wind erosio...Wind erosion represents a formidable environmental challenge and has serious negative impacts on soil health and agricultural productivity, particularly in arid and semi-arid areas. The complex dynamics of wind erosion make its large-scale monitoring and quantification a daunting task. To facilitate the monitoring and quantification of wind erosion, various scientific approaches and methods have been employed. These include sophisticated wind erosion equations and models, wind tunnel experiments, and the application of radionuclides. Additionally, researchers have assessed soil physicochemical properties, used anemometers for wind speed measurement, and deployed dust collectors for particle capture. Remote sensing technologies, wind erosion monitoring stations, and evaluations of wind barriers have also been utilized. Recently, the adoption of machine learning methods has gained popularity. Despite their value, each of these techniques has limitations in capturing the full spectrum of the wind erosion process. This paper examines these limitations and assesses the effectiveness of each method in the context of wind erosion studies. It also outlines directions for future research and suggests pathways that could enhance the understanding and management of wind erosion.展开更多
Typhoon-generated waves are simulated with two numerical wave models, the SWAN model for the coastal and Yangtze Estuary domain, nested within the WAVEWATCHIII （WW3） for the basin-scale East China Sea domain. Typhoo...Typhoon-generated waves are simulated with two numerical wave models, the SWAN model for the coastal and Yangtze Estuary domain, nested within the WAVEWATCHIII （WW3） for the basin-scale East China Sea domain. Typhoon No. 8114 is chosen because it was very strong, and generated high waves in the Estuary. WW3 was implemented for the East China Sea coarse-resolution computational domain, to simulate the waves over a large spatial scale and provide boundary conditions for SWAN model simulations, implemented on a fine-resolution nested domain for the Yangtze Estuary area. The Takahashi wind model is applied to the simulation of the East China Sea scale （3-hourly） and Yangtze Estuary scale （1-hourly） winds. Simulations of significant wave heights in the East China Sea show that the highest waves are on the right side of the storm track, and maxima tend to occur at the eastern deep-water open boundary of the Yangtze Estuary. In the Yangtze Estuary, incoming swell is dominant over locally generated waves before the typhoon approaches the Estuary. As the typhoon approaches the Estuary, wind waves and swell coexist, and the wave direction is mainly influenced by the swell direction and the complex topography.展开更多
The authors make an endeavor to explain why a new hybrid wave model is here proposed when several such models have already been in operation and the so- called third generation wave modej is proving attractive. This p...The authors make an endeavor to explain why a new hybrid wave model is here proposed when several such models have already been in operation and the so- called third generation wave modej is proving attractive. This part of the paper is devoted to the wind wave model. Both deep and shallow water models have been developed, the former being actually a special case of the latter when water depth is great. The deep water model is exceptionally simple in form. Significant wave height is the only prognostic variable. In comparison with the usual methods to compute the energy input and dissipations empirically or by 'tuning', the proposed model has the merit that the effects of all source terms are combined into one term which is computed through empirical growth relations for significant waves, these relations being, relatively speaking, easier and more reliable to obtain than those for the source terms in the spectral energy balance equation. The discrete part of the model and the implementation of the model as a whole will be discussed in the second part of the present paper.展开更多
Accurate wind modeling is important for wind resources assessment and wind power forecasting. To improve the WRF model configuration for the offshore wind modeling over the Baltic Sea, this study performed a sensitivi...Accurate wind modeling is important for wind resources assessment and wind power forecasting. To improve the WRF model configuration for the offshore wind modeling over the Baltic Sea, this study performed a sensitivity study of the WRF model to multiple model configurations, including domain setup,grid resolution, sea surface temperature, land surface data, and atmosphere-wave coupling. The simulated offshore wind was evaluated against LiDAR observations under different wind directions, atmospheric stabilities, and sea status. Generally, the simulated wind profiles matched observations, despite systematic underestimations. Strengthening the forcing from the reanalysis data through reducing the number of nested domains played the largest role in improving wind modeling. Atmosphere-wave coupling further improved the simulated wind, especially under the growing and mature sea conditions.Increasing the vertical resolution, and updating the sea surface temperature and the land surface information only had a slight impact, mainly visible during very stable conditions. Increasing the horizontal resolution also only had a slight impact, most visible during unstable conditions. Our study can help to improve the wind resources assessment and wind power forecasting over the Baltic Sea.展开更多
To ensure the stable operation of power systems with large proportions of wind power,China has published a series of national,industry,and enterprise standards for wind power.The increase in the number of standards an...To ensure the stable operation of power systems with large proportions of wind power,China has published a series of national,industry,and enterprise standards for wind power.The increase in the number of standards and the expansion of their application scope have given rise to a situation where multiple standards overlap and conflict with regard to the establishment of models and their applicability,resulting in unclear standard application scenarios.Therefore,it is imperative to analyze the development of wind-turbine and wind-farm modeling,along with the relevant standards.This paper presents the methods for wind-turbine modeling,the equivalent model of wind farms based on the general model of wind turbines,and the technical provisions and application scenarios involved in the relevant domestic and international standards.The adaptability of the relevant standards is examined.The results of this study are helpful for advancing wind power generation in China and ensuring the safe and stable operation of large-scale wind power systems.展开更多
An elliptical wind field model of typhoons is put forward based on the characteristics of the typhoon wind fields occurring in the Yellow Sea and Bohai Sea. By contrasting it with the circular typhoon wind field model...An elliptical wind field model of typhoons is put forward based on the characteristics of the typhoon wind fields occurring in the Yellow Sea and Bohai Sea. By contrasting it with the circular typhoon wind field model, it is found that the elliptical model can adequately represent the real wind field and trace the process of a typhoon storm surge. The numerically simulated results of storm surges by using the elliptical model are in good agreement with the observations and markedly better than those by using the circular model.展开更多
The shear stress generated by the wind on the land surface is the driving force that results in the wind erosion of the soil.It is an independent factor influencing soil wind erosion.The factors related to wind erosiv...The shear stress generated by the wind on the land surface is the driving force that results in the wind erosion of the soil.It is an independent factor influencing soil wind erosion.The factors related to wind erosivity,known as submodels,mainly include the weather factor(WF)in revised wind erosion equation(RWEQ),the erosion submodel(ES)in wind erosion prediction system(WEPS),as well as the drift potential(DP)in wind energy environmental assessment.However,the essential factors of WF and ES contain wind,soil characteristics and surface coverings,which therefore results in the interdependence between WF or ES and other factors(e.g.,soil erodible factor)in soil erosion models.Considering that DP is a relative indicator of the wind energy environment and does not have the value of expressing wind to induce shear stress on the surface.Therefore,a new factor is needed to express accurately wind erosivity.Based on the theoretical basis that the soil loss by wind erosion(Q)is proportional to the shear stress of the wind on the soil surface,a new model of wind driving force(WDF)was established,which expresses the potential capacity of wind to drive soil mass in per unit area and a period of time.Through the calculations in the typical area,the WDF,WF and DP are compared and analyzed from the theoretical basis,construction goal,problem-solving ability and typical area application;the spatial distribution of soil wind erosion intensity was concurrently compared with the spatial distributions of the WDF,WF and DP values in the typical area.The results indicate that the WDF is better to reflect the potential capacity of wind erosivity than WF and DP,and that the WDF model is a good model with universal applicability and can be logically incorporated into the soil wind erosion models.展开更多
The simulation performance over complex building clusters of a wind simulation model（Wind Information Field Fast Analysis model, WIFFA） in a micro-scale air pollutant dispersion model system（Urban Microscale Air Po...The simulation performance over complex building clusters of a wind simulation model（Wind Information Field Fast Analysis model, WIFFA） in a micro-scale air pollutant dispersion model system（Urban Microscale Air Pollution dispersion Simulation model, UMAPS） is evaluated using various wind tunnel experimental data including the CEDVAL（Compilation of Experimental Data for Validation of Micro-Scale Dispersion Models） wind tunnel experiment data and the NJU-FZ experiment data（Nanjing University-Fang Zhuang neighborhood wind tunnel experiment data）. The results show that the wind model can reproduce the vortexes triggered by urban buildings well, and the flow patterns in urban street canyons and building clusters can also be represented. Due to the complex shapes of buildings and their distributions, the simulation deviations/discrepancies from the measurements are usually caused by the simplification of the building shapes and the determination of the key zone sizes. The computational efficiencies of different cases are also discussed in this paper. The model has a high computational efficiency compared to traditional numerical models that solve the Navier–Stokes equations, and can produce very high-resolution（1–5 m） wind fields of a complex neighborhood scale urban building canopy（～ 1 km ×1km） in less than 3 min when run on a personal computer.展开更多
Modeling and validation of full power converter wind turbine models with field measurement data are rarely reported in papers. In this paper an aggregated generic dynamic model of the wind farm consisting of full powe...Modeling and validation of full power converter wind turbine models with field measurement data are rarely reported in papers. In this paper an aggregated generic dynamic model of the wind farm consisting of full power converter wind turbines is composed and the model validation based on actual field measurements is performed. The paper is based on the measurements obtained from the real short circuit test applied to connection point of observed wind farm. The presented approach for validating the composed model and fault ride-through （FRT） capability for the whole wind park is unique in overall practice and its significance and importance is described and analyzed.展开更多
A synoptic-scale upwelling event that developed off the east coast of the Hainan Island（EHIU） in the summer of 2010 is defi ned well via processing the Moderate Resolution Imaging Spectroradiometer（MODIS） sea surf...A synoptic-scale upwelling event that developed off the east coast of the Hainan Island（EHIU） in the summer of 2010 is defi ned well via processing the Moderate Resolution Imaging Spectroradiometer（MODIS） sea surface temperature（SST） data. The Regional Ocean Modeling System（ROMS） with high spatial resolution has been used to investigate this upwelling event. By comparing the ROMS results against tide station data, Argo fl oat profi les and MODIS SST, it is confi rmed that the ROMS reproduces the EHIU well. The cooler-water core（CWC） distinguished by waters（27） 27.5℃ in the EHIU, which occurred in the east Qiongzhou Strait mouth area and was bounded by a high temperature gradient, was the focus of this paper. Vertical structure of the CWC suggests that interaction between the westward fl ow and the bathymetry slope played a signifi cant role in the formation of CWC. Numerical experiments indicated that the westward fl ow in the Qiongzhou Strait was the result of tidal rectifi cation over variable topography（Shi et al., 2002）, thus tides played a critical role on the development of the CWC. The negative wind stress curl that dominated the east Qiongzhou Strait mouth area suppressed the intensity of the CWC by 0.2–0.4℃. Further, nonlinear interaction between tidal currents and wind stress enhanced vertical mixing greatly, which would benefi t the development of the CWC.展开更多
Traditionally,an empirical speed-up factor was introduced to reflect the effects of nonflat terrain on near-surface wind speeds.In this paper,the resistance effects of nonflat terrain are considered by introducing the...Traditionally,an empirical speed-up factor was introduced to reflect the effects of nonflat terrain on near-surface wind speeds.In this paper,the resistance effects of nonflat terrain are considered by introducing the terrain drag coefficient in the parametric wind field model for tropical cyclones(TCs)with a theoretical method.Terrain effects on wind fields are investigated in complex areas along the coastal zone in China under TC conditions.The results show that the terrain drag coefficient is the function of the slope angle and is sensitive to the spatial resolution.After including the resistance effect of nonflat terrain,the TC intensities weaken overall during landfall,with a slight enhancement near the coastal zone.The wind speeds outside the radius of the maximum wind speed decrease,while the wind speeds within the radius of the maximum wind speed increase.Both the TC eye and the radius of maximum wind speed shrink,which is more obvious when the TC center is entirely over land.As a result,the location and magnitude of the maximum wind speed are affected by the nonflat terrain.The changed structure of the wind fields demonstrates the necessity of considering the effects of nonflat terrain in simulating the wind fields under TC conditions.展开更多
The concept of the coherence function is adopted to find the wind pressure correlation of two points on domes of different rise-span ratios. The pressure measurements are made on the dome roof models by the wind tunne...The concept of the coherence function is adopted to find the wind pressure correlation of two points on domes of different rise-span ratios. The pressure measurements are made on the dome roof models by the wind tunnel test. The coherence functions for different separation distances at several directions of the domes from different wind directions are examined. The results show that there is a strong correlation for two adjacent points at low frequency, but not for non-adjacent points. The coherence of the wind pressure increases with the decrease in the separation distance. Moreover, the coherence of the wind pressure is in the strongest correlation on the along-wind direction at the same separation, but the lowest correlation is on the cross-wind direction. The detailed derivation of the proposed exponential coherence model of the wind pressure from experimental data is also discussed. It is found that the proposed exponential coherence model can be appropriate, especially, for small separations and the change in the directions on domes. Based on the quasi-steady theory, the relationship between the wind pressure and the wind velocity on the basis of the coherence model is also examined. The coherence observed between the wind pressure and the wind velocity is not adequately predicted by the quasi-steady theory.展开更多
This paper presents a study on the improvement of wind field hindcasts for two typical tropical cyclones, i.e., Fanapi and Meranti, which occurred in 2010. The performance of the three existing models for the hindcast...This paper presents a study on the improvement of wind field hindcasts for two typical tropical cyclones, i.e., Fanapi and Meranti, which occurred in 2010. The performance of the three existing models for the hindcasting of cyclone wind fields is first examined, and then two modification methods are proposed to improve the hindcasted results. The first one is the superposition method, which superposes the wind field calculated from the parametric cyclone model on that obtained from the cross-calibrated multi-platform （CCMP） reanalysis data. The radius used for the superposition is based on an analysis of the minimum difference between the two wind fields. The other one is the direct modification method, which directly modifies the CCMP reanalysis data according to the ratio of the measured maximum wind speed to the reanalyzed value as well as the distance from the cyclone center. Using these two methods, the problem of underestimation of strong winds in reanalysis data can be overcome. Both methods show considerable improvements in the hindcasting of tropical cyclone wind fields, compared with the cyclone wind model and the reanalysis data.展开更多
The induced airfl w from passing trains,which is recognized as train wind,usually has adverse impacts on people in the surroundings,i.e.,the aerodynamic forces generated by a high-speed train＇s wind may act on the hu...The induced airfl w from passing trains,which is recognized as train wind,usually has adverse impacts on people in the surroundings,i.e.,the aerodynamic forces generated by a high-speed train＇s wind may act on the human body and endanger the safety of pedestrians or roadside workers.In this paper,an improved delayed detached eddy simulation（IDDES） method is used to study train wind.The effects of the affiliate components and train length on train wind are analyzed.The results indicate that the aff liated components and train length have no effect on train wind in the area in front of the leading nose.In the downstream and wake regions,the longitudinal train wind becomes stronger as the length of the train increases,while the transverse train wind is not affected.The presence of affiliate components strengthens the train wind in the near fiel of the train because of strong fl w solid interactions but has limited effects on train wind in the far field.展开更多
Studies of wind erosion based on Geographic Information System（GIS） and Remote Sensing（RS） have not attracted sufficient attention because they are limited by natural and scientific factors.Few studies have been c...Studies of wind erosion based on Geographic Information System（GIS） and Remote Sensing（RS） have not attracted sufficient attention because they are limited by natural and scientific factors.Few studies have been conducted to estimate the intensity of large-scale wind erosion in Inner Mongolia,China.In the present study,a new model based on five factors including the number of snow cover days,soil erodibility,aridity,vegetation index and wind field intensity was developed to quantitatively estimate the amount of wind erosion.The results showed that wind erosion widely existed in Inner Mongolia.It covers an area of approximately 90×104 km2,accounting for 80% of the study region.During 1985–2011,wind erosion has aggravated over the entire region of Inner Mongolia,which was indicated by enlarged zones of erosion at severe,intensive and mild levels.In Inner Mongolia,a distinct spatial differentiation of wind erosion intensity was noted.The distribution of change intensity exhibited a downward trend that decreased from severe increase in the southwest to mild decrease in the northeast of the region.Zones occupied by barren land or sparse vegetation showed the most severe erosion,followed by land occupied by open shrubbery.Grasslands would have the most dramatic potential for changes in the future because these areas showed the largest fluctuation range of change intensity.In addition,a significantly negative relation was noted between change intensity and land slope.The relation between soil type and change intensity differed with the content of Ca CO3 and the surface composition of sandy,loamy and clayey soils with particle sizes of 0–1 cm.The results have certain significance for understanding the mechanism and change process of wind erosion that has occurred during the study period.Therefore,the present study can provide a scientific basis for the prevention and treatment of wind erosion in Inner Mongolia.展开更多
Multiyear observed time series of wind speed for selected points of the Arctic region (data of station network from the Kola Peninsula to the Chukotka Peninsula) are used to highlight the important peculiarities of wi...Multiyear observed time series of wind speed for selected points of the Arctic region (data of station network from the Kola Peninsula to the Chukotka Peninsula) are used to highlight the important peculiarities of wind speed extreme statistics. How largest extremes could be simulated by climate model (the INM-CM4 model data from the Historical experiment of the CMIP5) is also discussed. Extreme value analysis yielded that a volume of observed samples of wind speeds are strictly divided into two sets of variables. Statistical properties of one population are sharply different from another. Because the common statistical conditions are the sign of identity of extreme events we therefore hypothesize that two groups of extreme wind events adhere to different circulation processes. A very important message is that the procedure of selection can be realized easily based on analysis of the cumulative distribution function. The authors estimate the properties of the modelled extremes and conclude that they consist of only the samples, adhering to one group. This evidence provides a clue that atmospheric model with a coarse spatial resolution does not simulate special mechanism responsible for appearance of largest wind speed extremes. Therefore, the tasks where extreme wind is needed cannot be explicitly solved using the output of climate model. The finding that global models are unable to capture the wind extremes is already well known, but information that they are members of group with the specific statistical conditions provides new knowledge. Generally, the implemented analytical approach allows us to detect that the extreme wind speed events adhere to different statistical models. Events located above the threshold value are much more pronounced than representatives of another group (located below the threshold value) predicted by the extrapolation of law distributions in their tail. The same situation is found in different areas of science where the data referring to the same nomenclature are adhering to different statistical models. This result motivates our interest on our ability to detect, analyze, and understand such different extremes.展开更多
The presented method for numerical typhoon wave prediction is composed of a scheme for real time pressure forecasts, a marine wind numerical model and a typhoon wave numerical model. In the Northwest Pacific Ocean and...The presented method for numerical typhoon wave prediction is composed of a scheme for real time pressure forecasts, a marine wind numerical model and a typhoon wave numerical model. In the Northwest Pacific Ocean and China seas where water depth is over 20 m, a hybrid wave model [Wen Shengchang, Zhang Dacuo, Chen Bobal and Guo Peifang. 1989, Acta Oceanologica Sinica, 8 (1), 1～14; Zhang Dacuo, Wu Zengmao,Jiang Decai, Wang Wei, Chen Bobai, Tat Weitao, Wen Shengchang, Xu Qichun and Guo Peifaug. 1992, Acta Oceanologica Sinica, 11 (2), 157～178] is employed with 1°×1°grids, while in the South China Sea and East China Sea where typhoon frequently appears, the WAM model (WAMDI Group. 1988, Journal of Physical Oceanography, 18, 1755～1810) of shallow water version is embedded with (1 /4 )°×(1 /4)°grids. The boundary condition at the open boundary of the WAM model is provided by the hybrid model. After 3 a of testing forecasts(Yang Chuncheng, Dai Mingrui and Zhang Dacuo. 1992, International Symposium on Tropical Cyclone Disasters, October 12～16, Beijing, 404～409 ) and improvement, this system was put into operational use on the forecasting computer network of National Marine Environment Forecast Center of China in June, 1993. The wave predictions of 22 typhoon events show that the system is stable and prompt, and the forecast results are satisfactory. This system provides reliable numerical products for the disaster-prevention forecasts. The product is broadcasted in CCTV News at every noon.展开更多
Wind tunnel testing is experimental support of research and development during the design phase of aircraft and missile projects. The paper presents the developed method of manufacturing management by providing the re...Wind tunnel testing is experimental support of research and development during the design phase of aircraft and missile projects. The paper presents the developed method of manufacturing management by providing the required quality and accuracy of the wind tunnel models. The price of the wind tunnel model is several hundred thousand dollars and for this reason a manufacturing defect is not allowed. Additionally, any delays in the production process cause delay of testing in the wind tunnel. The costs of the delay are very high, because the wind tunnel laboratory is extremely expensive. All the foregoing is why the issue of the model＇s production is very important. Manufacturing of wind tunnel model within the contracted deadline and the required quality define tasks and objectives of production process management： identification of critical machining operations and activities; minimizing the time of coordinate inspections between cutting operations; identifying the main parameters of quality （shape, position in space, and angular relations）; and material management for all other machining operations that follow. Specially developed methods of coordinate metrology are crucial for the management of the manufacturing process. Worldwide used specialized coordinate inspection programs have no option to measure the flaps deflection angles and wing dihedral angle. This paper introduces the originally developed coordinate inspection methods for determining the angular relations between lift and control surfaces. The methods presented in this paper have been confirmed in several international projects. The quality and accuracy of the models for wind tunnel testing are conditio sine qua non.展开更多
An accurate probability distribution model of wind speed is critical to the assessment of reliability contribution of wind energy to power systems. Most of current models are built using the parametric density estimat...An accurate probability distribution model of wind speed is critical to the assessment of reliability contribution of wind energy to power systems. Most of current models are built using the parametric density estimation(PDE) methods, which usually assume that the wind speed are subordinate to a certain known distribution(e.g. Weibull distribution and Normal distribution) and estimate the parameters of models with the historical data. This paper presents a kernel density estimation(KDE) method which is a nonparametric way to estimate the probability density function(PDF) of wind speed. The method is a kind of data-driven approach without making any assumption on the form of the underlying wind speed distribution, and capable of uncovering the statistical information hidden in the historical data. The proposed method is compared with three parametric models using wind data from six sites.The results indicate that the KDE outperforms the PDE in terms of accuracy and flexibility in describing the longterm wind speed distributions for all sites. A sensitivity analysis with respect to kernel functions is presented and Gauss kernel function is proved to be the best one. Case studies on a standard IEEE reliability test system(IEEERTS) have verified the applicability and effectiveness of the proposed model in evaluating the reliability performance of wind farms.展开更多
Tropical cyclones(TCs) cause catastrophic loss in many coastal areas of the world. TC wind hazard maps can play an important role in disaster management. A good representation of local factors reflecting the effects o...Tropical cyclones(TCs) cause catastrophic loss in many coastal areas of the world. TC wind hazard maps can play an important role in disaster management. A good representation of local factors reflecting the effects of spatially heterogeneous terrain and land cover is critical to evaluation of TC wind hazard. Very few studies, however,provide global wind hazard assessment results that consider detailed local effects. In this study, the wind fields of historical TCs were simulated with parametric models in which the planetary boundary layer models explicitly integrate local effects at 1 km resolution. The topographic effects for eight wind directions were quantified over four types of terrain(ground, escarpment, ridge, and valley),and the surface roughness lengths were estimated from a global land cover map. The missing TC parameters in the best track datasets were reconstructed with local regression models. Finally, an example of a wind hazard map in the form of wind speeds under a 100-year return period and corresponding uncertainties was created based on a statistical analysis of reconstructed historical wind fields over seven of the world's ocean basins.展开更多
文摘Wind erosion represents a formidable environmental challenge and has serious negative impacts on soil health and agricultural productivity, particularly in arid and semi-arid areas. The complex dynamics of wind erosion make its large-scale monitoring and quantification a daunting task. To facilitate the monitoring and quantification of wind erosion, various scientific approaches and methods have been employed. These include sophisticated wind erosion equations and models, wind tunnel experiments, and the application of radionuclides. Additionally, researchers have assessed soil physicochemical properties, used anemometers for wind speed measurement, and deployed dust collectors for particle capture. Remote sensing technologies, wind erosion monitoring stations, and evaluations of wind barriers have also been utilized. Recently, the adoption of machine learning methods has gained popularity. Despite their value, each of these techniques has limitations in capturing the full spectrum of the wind erosion process. This paper examines these limitations and assesses the effectiveness of each method in the context of wind erosion studies. It also outlines directions for future research and suggests pathways that could enhance the understanding and management of wind erosion.
基金This project is supported bythe Canadian Panel on Energy Research and Development (Offshore Environmental Fac-tors Program) , ONR (US Office of Naval Research) via GoMOOS-the Gulf of Maine Ocean Observing System,Petroleum Research Atlantic Canada (PRAC) ,and the CFCAS (Canada Foundation for Climate and AtmosphericStudies) ,Canadian Panel on Energy Research and Development (Offshore Environmental Factors Program) .It is al-so supported bythe Advanced Doctoral Fund of the Ministry of Education of China (Grant No.20030294010)
文摘Typhoon-generated waves are simulated with two numerical wave models, the SWAN model for the coastal and Yangtze Estuary domain, nested within the WAVEWATCHIII （WW3） for the basin-scale East China Sea domain. Typhoon No. 8114 is chosen because it was very strong, and generated high waves in the Estuary. WW3 was implemented for the East China Sea coarse-resolution computational domain, to simulate the waves over a large spatial scale and provide boundary conditions for SWAN model simulations, implemented on a fine-resolution nested domain for the Yangtze Estuary area. The Takahashi wind model is applied to the simulation of the East China Sea scale （3-hourly） and Yangtze Estuary scale （1-hourly） winds. Simulations of significant wave heights in the East China Sea show that the highest waves are on the right side of the storm track, and maxima tend to occur at the eastern deep-water open boundary of the Yangtze Estuary. In the Yangtze Estuary, incoming swell is dominant over locally generated waves before the typhoon approaches the Estuary. As the typhoon approaches the Estuary, wind waves and swell coexist, and the wave direction is mainly influenced by the swell direction and the complex topography.
文摘The authors make an endeavor to explain why a new hybrid wave model is here proposed when several such models have already been in operation and the so- called third generation wave modej is proving attractive. This part of the paper is devoted to the wind wave model. Both deep and shallow water models have been developed, the former being actually a special case of the latter when water depth is great. The deep water model is exceptionally simple in form. Significant wave height is the only prognostic variable. In comparison with the usual methods to compute the energy input and dissipations empirically or by 'tuning', the proposed model has the merit that the effects of all source terms are combined into one term which is computed through empirical growth relations for significant waves, these relations being, relatively speaking, easier and more reliable to obtain than those for the source terms in the spectral energy balance equation. The discrete part of the model and the implementation of the model as a whole will be discussed in the second part of the present paper.
基金This project was funded by Energimyndigheten[Grant No.47054-1]funded by the Swedish Research Council[Grant No.2012-03902]+4 种基金Uppsala Universitypart of the Swedish strategic research program StandUp for Windsupported by Formas project[2017-00516]Laboratory for Regional Oceanography and Numerical Modeling,Qingdao National Laboratory for Marine Science and Technology[No.2019B04)partially funded by the Swedish Research Council through grant agreement[No.2018-05973]。
文摘Accurate wind modeling is important for wind resources assessment and wind power forecasting. To improve the WRF model configuration for the offshore wind modeling over the Baltic Sea, this study performed a sensitivity study of the WRF model to multiple model configurations, including domain setup,grid resolution, sea surface temperature, land surface data, and atmosphere-wave coupling. The simulated offshore wind was evaluated against LiDAR observations under different wind directions, atmospheric stabilities, and sea status. Generally, the simulated wind profiles matched observations, despite systematic underestimations. Strengthening the forcing from the reanalysis data through reducing the number of nested domains played the largest role in improving wind modeling. Atmosphere-wave coupling further improved the simulated wind, especially under the growing and mature sea conditions.Increasing the vertical resolution, and updating the sea surface temperature and the land surface information only had a slight impact, mainly visible during very stable conditions. Increasing the horizontal resolution also only had a slight impact, most visible during unstable conditions. Our study can help to improve the wind resources assessment and wind power forecasting over the Baltic Sea.
基金supported in part by the Joint Research Fund in Smart Grid (U1966208) under a cooperative agreement between the National Natural Science Foundation of China (NSFC) and State Grid Corporation of China (SGCC)
文摘To ensure the stable operation of power systems with large proportions of wind power,China has published a series of national,industry,and enterprise standards for wind power.The increase in the number of standards and the expansion of their application scope have given rise to a situation where multiple standards overlap and conflict with regard to the establishment of models and their applicability,resulting in unclear standard application scenarios.Therefore,it is imperative to analyze the development of wind-turbine and wind-farm modeling,along with the relevant standards.This paper presents the methods for wind-turbine modeling,the equivalent model of wind farms based on the general model of wind turbines,and the technical provisions and application scenarios involved in the relevant domestic and international standards.The adaptability of the relevant standards is examined.The results of this study are helpful for advancing wind power generation in China and ensuring the safe and stable operation of large-scale wind power systems.
基金supported by the Nationa1 High Technology Research and Development Program of China(863 Program)(Grant No.2002AA639370)the Natural Science Foundation of Shandong Province(Grant No.Q99E02)the Special Fund of Excellent Ph.D Dissertation(200021).
文摘An elliptical wind field model of typhoons is put forward based on the characteristics of the typhoon wind fields occurring in the Yellow Sea and Bohai Sea. By contrasting it with the circular typhoon wind field model, it is found that the elliptical model can adequately represent the real wind field and trace the process of a typhoon storm surge. The numerically simulated results of storm surges by using the elliptical model are in good agreement with the observations and markedly better than those by using the circular model.
基金This work was supported by the National Natural Science Foundation of China(41330746,41630747).
文摘The shear stress generated by the wind on the land surface is the driving force that results in the wind erosion of the soil.It is an independent factor influencing soil wind erosion.The factors related to wind erosivity,known as submodels,mainly include the weather factor(WF)in revised wind erosion equation(RWEQ),the erosion submodel(ES)in wind erosion prediction system(WEPS),as well as the drift potential(DP)in wind energy environmental assessment.However,the essential factors of WF and ES contain wind,soil characteristics and surface coverings,which therefore results in the interdependence between WF or ES and other factors(e.g.,soil erodible factor)in soil erosion models.Considering that DP is a relative indicator of the wind energy environment and does not have the value of expressing wind to induce shear stress on the surface.Therefore,a new factor is needed to express accurately wind erosivity.Based on the theoretical basis that the soil loss by wind erosion(Q)is proportional to the shear stress of the wind on the soil surface,a new model of wind driving force(WDF)was established,which expresses the potential capacity of wind to drive soil mass in per unit area and a period of time.Through the calculations in the typical area,the WDF,WF and DP are compared and analyzed from the theoretical basis,construction goal,problem-solving ability and typical area application;the spatial distribution of soil wind erosion intensity was concurrently compared with the spatial distributions of the WDF,WF and DP values in the typical area.The results indicate that the WDF is better to reflect the potential capacity of wind erosivity than WF and DP,and that the WDF model is a good model with universal applicability and can be logically incorporated into the soil wind erosion models.
基金supported by the China Special Fund for Meteorological Research in the Public Interest(Grant No.GYHY201106049)the National Natural Science Foundation of China(Grant Nos.51538005 and 41375014)the Jiangsu Collaborative Innovation Center for Climate Change,China
文摘The simulation performance over complex building clusters of a wind simulation model（Wind Information Field Fast Analysis model, WIFFA） in a micro-scale air pollutant dispersion model system（Urban Microscale Air Pollution dispersion Simulation model, UMAPS） is evaluated using various wind tunnel experimental data including the CEDVAL（Compilation of Experimental Data for Validation of Micro-Scale Dispersion Models） wind tunnel experiment data and the NJU-FZ experiment data（Nanjing University-Fang Zhuang neighborhood wind tunnel experiment data）. The results show that the wind model can reproduce the vortexes triggered by urban buildings well, and the flow patterns in urban street canyons and building clusters can also be represented. Due to the complex shapes of buildings and their distributions, the simulation deviations/discrepancies from the measurements are usually caused by the simplification of the building shapes and the determination of the key zone sizes. The computational efficiencies of different cases are also discussed in this paper. The model has a high computational efficiency compared to traditional numerical models that solve the Navier–Stokes equations, and can produce very high-resolution（1–5 m） wind fields of a complex neighborhood scale urban building canopy（～ 1 km ×1km） in less than 3 min when run on a personal computer.
文摘Modeling and validation of full power converter wind turbine models with field measurement data are rarely reported in papers. In this paper an aggregated generic dynamic model of the wind farm consisting of full power converter wind turbines is composed and the model validation based on actual field measurements is performed. The paper is based on the measurements obtained from the real short circuit test applied to connection point of observed wind farm. The presented approach for validating the composed model and fault ride-through （FRT） capability for the whole wind park is unique in overall practice and its significance and importance is described and analyzed.
基金Supported by the National Natural Science Foundation of China(No.41476002)the Shandong Province Natural Science Foundation(No.ZR2014DQ013)the State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences(No.LTO1409)
文摘A synoptic-scale upwelling event that developed off the east coast of the Hainan Island（EHIU） in the summer of 2010 is defi ned well via processing the Moderate Resolution Imaging Spectroradiometer（MODIS） sea surface temperature（SST） data. The Regional Ocean Modeling System（ROMS） with high spatial resolution has been used to investigate this upwelling event. By comparing the ROMS results against tide station data, Argo fl oat profi les and MODIS SST, it is confi rmed that the ROMS reproduces the EHIU well. The cooler-water core（CWC） distinguished by waters（27） 27.5℃ in the EHIU, which occurred in the east Qiongzhou Strait mouth area and was bounded by a high temperature gradient, was the focus of this paper. Vertical structure of the CWC suggests that interaction between the westward fl ow and the bathymetry slope played a signifi cant role in the formation of CWC. Numerical experiments indicated that the westward fl ow in the Qiongzhou Strait was the result of tidal rectifi cation over variable topography（Shi et al., 2002）, thus tides played a critical role on the development of the CWC. The negative wind stress curl that dominated the east Qiongzhou Strait mouth area suppressed the intensity of the CWC by 0.2–0.4℃. Further, nonlinear interaction between tidal currents and wind stress enhanced vertical mixing greatly, which would benefi t the development of the CWC.
基金supported by the Key Program of National Natural Science Foundation of China (Grant No.U2142206)the Shanghai Science and Technology Commission Project (Grant No.23DZ204701)the Natural Science Foundation of Shanghai (Grant No.19ZR1469200).
文摘Traditionally,an empirical speed-up factor was introduced to reflect the effects of nonflat terrain on near-surface wind speeds.In this paper,the resistance effects of nonflat terrain are considered by introducing the terrain drag coefficient in the parametric wind field model for tropical cyclones(TCs)with a theoretical method.Terrain effects on wind fields are investigated in complex areas along the coastal zone in China under TC conditions.The results show that the terrain drag coefficient is the function of the slope angle and is sensitive to the spatial resolution.After including the resistance effect of nonflat terrain,the TC intensities weaken overall during landfall,with a slight enhancement near the coastal zone.The wind speeds outside the radius of the maximum wind speed decrease,while the wind speeds within the radius of the maximum wind speed increase.Both the TC eye and the radius of maximum wind speed shrink,which is more obvious when the TC center is entirely over land.As a result,the location and magnitude of the maximum wind speed are affected by the nonflat terrain.The changed structure of the wind fields demonstrates the necessity of considering the effects of nonflat terrain in simulating the wind fields under TC conditions.
基金The National Natural Science Foundation of China (No.50678036)
文摘The concept of the coherence function is adopted to find the wind pressure correlation of two points on domes of different rise-span ratios. The pressure measurements are made on the dome roof models by the wind tunnel test. The coherence functions for different separation distances at several directions of the domes from different wind directions are examined. The results show that there is a strong correlation for two adjacent points at low frequency, but not for non-adjacent points. The coherence of the wind pressure increases with the decrease in the separation distance. Moreover, the coherence of the wind pressure is in the strongest correlation on the along-wind direction at the same separation, but the lowest correlation is on the cross-wind direction. The detailed derivation of the proposed exponential coherence model of the wind pressure from experimental data is also discussed. It is found that the proposed exponential coherence model can be appropriate, especially, for small separations and the change in the directions on domes. Based on the quasi-steady theory, the relationship between the wind pressure and the wind velocity on the basis of the coherence model is also examined. The coherence observed between the wind pressure and the wind velocity is not adequately predicted by the quasi-steady theory.
基金supported by the National Natural Science Foundation of China(Grants No.51309092 and 51379072)the Special Fund for Public Welfare Industry of the Ministry of Water Resources of China(Grant No.201201045)+1 种基金the Natural Science Fund for Colleges and Universities in Jiangsu Province(Grant No.BK20130833)the Fundamental Research Funds for the Central Universities(Grants No.2015B16014 and 2013B03414)
文摘This paper presents a study on the improvement of wind field hindcasts for two typical tropical cyclones, i.e., Fanapi and Meranti, which occurred in 2010. The performance of the three existing models for the hindcasting of cyclone wind fields is first examined, and then two modification methods are proposed to improve the hindcasted results. The first one is the superposition method, which superposes the wind field calculated from the parametric cyclone model on that obtained from the cross-calibrated multi-platform （CCMP） reanalysis data. The radius used for the superposition is based on an analysis of the minimum difference between the two wind fields. The other one is the direct modification method, which directly modifies the CCMP reanalysis data according to the ratio of the measured maximum wind speed to the reanalyzed value as well as the distance from the cyclone center. Using these two methods, the problem of underestimation of strong winds in reanalysis data can be overcome. Both methods show considerable improvements in the hindcasting of tropical cyclone wind fields, compared with the cyclone wind model and the reanalysis data.
文摘The induced airfl w from passing trains,which is recognized as train wind,usually has adverse impacts on people in the surroundings,i.e.,the aerodynamic forces generated by a high-speed train＇s wind may act on the human body and endanger the safety of pedestrians or roadside workers.In this paper,an improved delayed detached eddy simulation（IDDES） method is used to study train wind.The effects of the affiliate components and train length on train wind are analyzed.The results indicate that the aff liated components and train length have no effect on train wind in the area in front of the leading nose.In the downstream and wake regions,the longitudinal train wind becomes stronger as the length of the train increases,while the transverse train wind is not affected.The presence of affiliate components strengthens the train wind in the near fiel of the train because of strong fl w solid interactions but has limited effects on train wind in the far field.
基金supported by the National Natural Science Foundation of China (41201441,41371363,41301501)Foundation of Director of Institute of Remote Sensing and Digital Earth,Chinese Academy of Science (Y4SY0200CX)Guangxi Key Laboratory of Spatial Information and Geomatics (1207115-18)
文摘Studies of wind erosion based on Geographic Information System（GIS） and Remote Sensing（RS） have not attracted sufficient attention because they are limited by natural and scientific factors.Few studies have been conducted to estimate the intensity of large-scale wind erosion in Inner Mongolia,China.In the present study,a new model based on five factors including the number of snow cover days,soil erodibility,aridity,vegetation index and wind field intensity was developed to quantitatively estimate the amount of wind erosion.The results showed that wind erosion widely existed in Inner Mongolia.It covers an area of approximately 90×104 km2,accounting for 80% of the study region.During 1985–2011,wind erosion has aggravated over the entire region of Inner Mongolia,which was indicated by enlarged zones of erosion at severe,intensive and mild levels.In Inner Mongolia,a distinct spatial differentiation of wind erosion intensity was noted.The distribution of change intensity exhibited a downward trend that decreased from severe increase in the southwest to mild decrease in the northeast of the region.Zones occupied by barren land or sparse vegetation showed the most severe erosion,followed by land occupied by open shrubbery.Grasslands would have the most dramatic potential for changes in the future because these areas showed the largest fluctuation range of change intensity.In addition,a significantly negative relation was noted between change intensity and land slope.The relation between soil type and change intensity differed with the content of Ca CO3 and the surface composition of sandy,loamy and clayey soils with particle sizes of 0–1 cm.The results have certain significance for understanding the mechanism and change process of wind erosion that has occurred during the study period.Therefore,the present study can provide a scientific basis for the prevention and treatment of wind erosion in Inner Mongolia.
文摘Multiyear observed time series of wind speed for selected points of the Arctic region (data of station network from the Kola Peninsula to the Chukotka Peninsula) are used to highlight the important peculiarities of wind speed extreme statistics. How largest extremes could be simulated by climate model (the INM-CM4 model data from the Historical experiment of the CMIP5) is also discussed. Extreme value analysis yielded that a volume of observed samples of wind speeds are strictly divided into two sets of variables. Statistical properties of one population are sharply different from another. Because the common statistical conditions are the sign of identity of extreme events we therefore hypothesize that two groups of extreme wind events adhere to different circulation processes. A very important message is that the procedure of selection can be realized easily based on analysis of the cumulative distribution function. The authors estimate the properties of the modelled extremes and conclude that they consist of only the samples, adhering to one group. This evidence provides a clue that atmospheric model with a coarse spatial resolution does not simulate special mechanism responsible for appearance of largest wind speed extremes. Therefore, the tasks where extreme wind is needed cannot be explicitly solved using the output of climate model. The finding that global models are unable to capture the wind extremes is already well known, but information that they are members of group with the specific statistical conditions provides new knowledge. Generally, the implemented analytical approach allows us to detect that the extreme wind speed events adhere to different statistical models. Events located above the threshold value are much more pronounced than representatives of another group (located below the threshold value) predicted by the extrapolation of law distributions in their tail. The same situation is found in different areas of science where the data referring to the same nomenclature are adhering to different statistical models. This result motivates our interest on our ability to detect, analyze, and understand such different extremes.
文摘The presented method for numerical typhoon wave prediction is composed of a scheme for real time pressure forecasts, a marine wind numerical model and a typhoon wave numerical model. In the Northwest Pacific Ocean and China seas where water depth is over 20 m, a hybrid wave model [Wen Shengchang, Zhang Dacuo, Chen Bobal and Guo Peifang. 1989, Acta Oceanologica Sinica, 8 (1), 1～14; Zhang Dacuo, Wu Zengmao,Jiang Decai, Wang Wei, Chen Bobai, Tat Weitao, Wen Shengchang, Xu Qichun and Guo Peifaug. 1992, Acta Oceanologica Sinica, 11 (2), 157～178] is employed with 1°×1°grids, while in the South China Sea and East China Sea where typhoon frequently appears, the WAM model (WAMDI Group. 1988, Journal of Physical Oceanography, 18, 1755～1810) of shallow water version is embedded with (1 /4 )°×(1 /4)°grids. The boundary condition at the open boundary of the WAM model is provided by the hybrid model. After 3 a of testing forecasts(Yang Chuncheng, Dai Mingrui and Zhang Dacuo. 1992, International Symposium on Tropical Cyclone Disasters, October 12～16, Beijing, 404～409 ) and improvement, this system was put into operational use on the forecasting computer network of National Marine Environment Forecast Center of China in June, 1993. The wave predictions of 22 typhoon events show that the system is stable and prompt, and the forecast results are satisfactory. This system provides reliable numerical products for the disaster-prevention forecasts. The product is broadcasted in CCTV News at every noon.
文摘Wind tunnel testing is experimental support of research and development during the design phase of aircraft and missile projects. The paper presents the developed method of manufacturing management by providing the required quality and accuracy of the wind tunnel models. The price of the wind tunnel model is several hundred thousand dollars and for this reason a manufacturing defect is not allowed. Additionally, any delays in the production process cause delay of testing in the wind tunnel. The costs of the delay are very high, because the wind tunnel laboratory is extremely expensive. All the foregoing is why the issue of the model＇s production is very important. Manufacturing of wind tunnel model within the contracted deadline and the required quality define tasks and objectives of production process management： identification of critical machining operations and activities; minimizing the time of coordinate inspections between cutting operations; identifying the main parameters of quality （shape, position in space, and angular relations）; and material management for all other machining operations that follow. Specially developed methods of coordinate metrology are crucial for the management of the manufacturing process. Worldwide used specialized coordinate inspection programs have no option to measure the flaps deflection angles and wing dihedral angle. This paper introduces the originally developed coordinate inspection methods for determining the angular relations between lift and control surfaces. The methods presented in this paper have been confirmed in several international projects. The quality and accuracy of the models for wind tunnel testing are conditio sine qua non.
基金supported in part by the National Natural Science Foundation of China(No.51307185)Natural Science Foundation Project of CQ CSTC(No.cstc2012jjA90004)the Fundamental Research Funds for the Central Universities(No.CDJPY12150002)
文摘An accurate probability distribution model of wind speed is critical to the assessment of reliability contribution of wind energy to power systems. Most of current models are built using the parametric density estimation(PDE) methods, which usually assume that the wind speed are subordinate to a certain known distribution(e.g. Weibull distribution and Normal distribution) and estimate the parameters of models with the historical data. This paper presents a kernel density estimation(KDE) method which is a nonparametric way to estimate the probability density function(PDF) of wind speed. The method is a kind of data-driven approach without making any assumption on the form of the underlying wind speed distribution, and capable of uncovering the statistical information hidden in the historical data. The proposed method is compared with three parametric models using wind data from six sites.The results indicate that the KDE outperforms the PDE in terms of accuracy and flexibility in describing the longterm wind speed distributions for all sites. A sensitivity analysis with respect to kernel functions is presented and Gauss kernel function is proved to be the best one. Case studies on a standard IEEE reliability test system(IEEERTS) have verified the applicability and effectiveness of the proposed model in evaluating the reliability performance of wind farms.
基金supported by the National Key Research and Development Program of China(No.2017YFA0604903)
文摘Tropical cyclones(TCs) cause catastrophic loss in many coastal areas of the world. TC wind hazard maps can play an important role in disaster management. A good representation of local factors reflecting the effects of spatially heterogeneous terrain and land cover is critical to evaluation of TC wind hazard. Very few studies, however,provide global wind hazard assessment results that consider detailed local effects. In this study, the wind fields of historical TCs were simulated with parametric models in which the planetary boundary layer models explicitly integrate local effects at 1 km resolution. The topographic effects for eight wind directions were quantified over four types of terrain(ground, escarpment, ridge, and valley),and the surface roughness lengths were estimated from a global land cover map. The missing TC parameters in the best track datasets were reconstructed with local regression models. Finally, an example of a wind hazard map in the form of wind speeds under a 100-year return period and corresponding uncertainties was created based on a statistical analysis of reconstructed historical wind fields over seven of the world's ocean basins.
