Oil spill prediction is critical for reducing the detrimental impact of oil spills on marine ecosystems,and the wind strong-ly influences the performance of oil spill models.However,the wind drift factor is assumed to...Oil spill prediction is critical for reducing the detrimental impact of oil spills on marine ecosystems,and the wind strong-ly influences the performance of oil spill models.However,the wind drift factor is assumed to be constant or parameterized by linear regression and other methods in existing studies,which may limit the accuracy of the oil spill simulation.A parameterization method for wind drift factor(PMOWDF)based on deep learning,which can effectively extract the time-varying characteristics on a regional scale,is proposed in this paper.The method was adopted to forecast the oil spill in the East China Sea.The discrepancies between predicted positions and actual measurement locations of the drifters are obtained using seasonal statistical analysis.Results reveal that PMOWDF can improve the accuracy of oil spill simulation compared with the traditional method.Furthermore,the parameteriza-tion method is validated with satellite observations of the Sanchi oil spill in 2018.展开更多
A weed is a plant that thrives in areas of human disturbance, such as gardens, fields, pastures, waysides, and waste places where it is not intentionally cultivated. Dispersal affects community dynamics and vegetation...A weed is a plant that thrives in areas of human disturbance, such as gardens, fields, pastures, waysides, and waste places where it is not intentionally cultivated. Dispersal affects community dynamics and vegetation response to global change. The process of seed disposal is influenced by wind, which plays a crucial role in determining the distance and probability of seed dispersal. Existing models of seed dispersal consider wind direction but fail to incorporate wind intensity. In this paper, a novel seed disposal model was proposed in this paper, incorporating wind intensity based on relevant references. According to various climatic conditions, including temperate, arid, and tropical regions, three specific regions were selected to establish a wind dispersal model that accurately reflects the density function distribution of dispersal distance. Additionally, dandelions growth is influenced by a multitude of factors, encompassing temperature, humidity, climate, and various environmental variables that necessitate meticulous consideration. Based on Factor Analysis model, which completely considers temperature, precipitation, solar radiation, wind, and land carrying capacity, a conclusion is presented, indicating that the growth of seeds is primarily influenced by plant attributes and climate conditions, with the former exerting a relatively stronger impact. Subsequently, the remaining two plants were chosen based on seed weight, yielding consistent conclusion.展开更多
Wind data were collected during the 2011 typhoon Meari at heights of 10, 20, 30, and 40 m above the ground using a 40 m high anemometer tower in the coastal area near Shanghai Pudong International Airport. Wind speeds...Wind data were collected during the 2011 typhoon Meari at heights of 10, 20, 30, and 40 m above the ground using a 40 m high anemometer tower in the coastal area near Shanghai Pudong International Airport. Wind speeds and directions, turbulence intensities, gust factors, and peaks were analyzed using the time records of wind speed. The results show that turbulence intensity components in longitudinal, lateral, and vertical directions decrease with mean wind speed, regardless of elevations, and the turbulence intensities are in a linear relationship with mean wind speeds. The ratios of three turbulence intensity components(i.e. Iu, Iv, Iw) at heights of 10, 20 and 40 m were calculated and equal to be 1:0.88:0.50, 1:0.84:0.57, and 1:0.9:0.49, respectively. In addition, the gust factors in three directions exhibit a reduction with increasing mean wind speed. The peak factors at different heights show a similar trend and slightly decrease with mean wind speed; average peak factors for all 10-min data from Typhoon Meari are 2.43, 2.48, and 2.47, respectively.展开更多
Improvements in the aerodynamic design will lead to more efficiency of wind turbines and higher power production. In the present study, a 3D parametric gas turbine blade geometry building code, 3DBGB, has been modifie...Improvements in the aerodynamic design will lead to more efficiency of wind turbines and higher power production. In the present study, a 3D parametric gas turbine blade geometry building code, 3DBGB, has been modified in order to include wind turbine design capabilities. This approach enables greater flexibility of the design along with the ability to design more complex geometries with relative ease. The NREL NASA Phase VI wind turbine was considered as a test case for validation and as a baseline by which modified designs could be compared. The design parameters were translated into 3DBGB input to create a 3D model of the wind turbine which can also be imported into any CAD program. Design modifications included replacing the airfoil section and modifying the thickness to chord ratio as a function of span. These models were imported into a high-fidelity CFD package, Fine/TURBO by NUMECA. Fine/TURBO is a specialized CFD platform for turbo-machinery analysis. A code-geomturbo was used to convert the 3D model of the wind turbine into the native format used to define geometries in the Fine/TURBO meshing tool, AutoGrid. The CFD results were post processed using a 3D force analysis code. The radial force variations were found to play a measurable role in the performance of wind turbine blades. The radial component of the blade surface area as it varies in span is the dominant contributor of the radial forces. Through the radial momentum equation, this radial force variation is responsible for creating the streamline curvature that leads to the expansion of the streamtube (slipstream) that is responsible for slowing the wind velocity ahead of the wind turbine leading edge, which is quantified as the axial induction factor. These same radial forces also play a role in changing the slipstream for propellers. Through the design modifications, simulated with CFD and post-processed appropriately, this connection with the radial component of area to the radial forces to the axial induction factor, and finally the wind turbine power is demonstrated. The results from the CFD analysis and 3D force analysis are presented. For the case presented, the power increases by 5.6% due to changes in airfoil thickness only.展开更多
In this paper,areas and main factors of wind erosion in black earth region of Northeast China were systematically analyzed,as well as the development trend of wind erosion in black earth region of Northeast China.In a...In this paper,areas and main factors of wind erosion in black earth region of Northeast China were systematically analyzed,as well as the development trend of wind erosion in black earth region of Northeast China.In addition,development trend of wind erosion in black earth region of Northeast China was analyzed from the aspects of the geographic position,climatic change law in recent 40 years and effects of northeast sand land desertification on wind erosion in black earth region,which had provided references for the research and prevention of wind erosion in soil of black earth region of Northeast China.展开更多
Multi-phase machines are so attractive for electrical machine designers because of their valuable advantages such as high reliability and fault tolerant ability.Meanwhile,fractional slot concentrated windings(FSCW)are...Multi-phase machines are so attractive for electrical machine designers because of their valuable advantages such as high reliability and fault tolerant ability.Meanwhile,fractional slot concentrated windings(FSCW)are well known because of short end winding length,simple structure,field weakening sufficiency,fault tolerant capability and higher slot fill factor.The five-phase machines equipped with FSCW,are very good candidates for the purpose of designing motors for high reliable applications,like electric cars,major transporting buses,high speed trains and massive trucks.But,in comparison to the general distributed windings,the FSCWs contain high magnetomotive force(MMF)space harmonic contents,which cause unwanted effects on the machine ability,such as localized iron saturation and core losses.This manuscript introduces several new five-phase fractional slot winding layouts,by the means of slot shifting concept in order to design the new types of synchronous reluctance motors(SynRels).In order to examine the proposed winding’s performances,three sample machines are designed as case studies,and analytical study and finite element analysis(FEA)is used for validation.展开更多
Using Geographic Information System(GIS), based on wind speed, precipitation, topographic, soil, vegetation coverage and land use data of Inner Mongolia between 2001 and 2010, we applied the revised wind erosion equat...Using Geographic Information System(GIS), based on wind speed, precipitation, topographic, soil, vegetation coverage and land use data of Inner Mongolia between 2001 and 2010, we applied the revised wind erosion equation(RWEQ) model to simulate wind erosion intensity. The results showed that an area of approximately 47.8 × 10~4 km^2 experienced wind erosion in 2010, 23.2% of this erosion could be rated as severe, and 46.0% as moderate. Both the area and the intensity of wind erosion had decreased from 2001 to 2010, the wind erosion area reduced 10.1%, and wind erosion intensity decreased by 29.4%. Precipitation, wind speed, population size and urbanization in rural areas, and gross domestic product of primary industry(GDP1) were the main factors influencing wind erosion. Overall, these factors accounted for 88.8% of the wind erosion. These results indicated that the decrease in wind erosion over the past decade related to the increase in precipitation and the decrease in the number of windy days, while modest urban development and optimization of the economic structure might partially reduced the level of ecological pressure, highlighting the importance of human activities in controlling wind erosion.展开更多
To study the unsteady aerodynamic loads of high-speed trains in fluctuating crosswinds, the fluctuating winds of a moving point shifting with high-speed trains are calculated in this paper based on Cooper theory and h...To study the unsteady aerodynamic loads of high-speed trains in fluctuating crosswinds, the fluctuating winds of a moving point shifting with high-speed trains are calculated in this paper based on Cooper theory and harmonic superposition method. The computational fluid dynamics method is used to obtain the aerodynamic load coefficients at different mean yaw angles, and the aero- dynamic admittance function is introduced to calculate unsteady aerodynamic loads of high-speed trains in fluctuating winds. Using this method, the standard deviation and maximum value of the aerodynamic force (moment) are simulated. The results show that when the train speed is fixed, the varying mean wind speeds have large impact on the fluctuating value of the wind speeds and aerodynamic loads; in contrast, when the wind speed is fixed, the varying train speeds have little impact on the fluctuating value of the wind speeds or aerodynamic loads. The ratio of standard deviation to 0.SpKU2, or maximum value to 0.5pKU2, can be expressed as the function of mean yaw angle. The peak factors of the side force and roll moment are the same ( - 3.28), the peak factor of the lift force is - 3.33, and the peak factors of the yaw moment and pitch moment are also the same (- 3.77).展开更多
Wind loading study on a cable-net supported glass wall is conducted by means of wind tunnel tests. An equiva- lent aeroelastic model is designed and constructed. Response of displacements of the wall is measured and a...Wind loading study on a cable-net supported glass wall is conducted by means of wind tunnel tests. An equiva- lent aeroelastic model is designed and constructed. Response of displacements of the wall is measured and analyzed. In order to design a glass wall under wind loading, the "wind- vibration factor" is estimated and discussed. In fact, the mech- anism of wind acting on the wall is commonly known not only as positive pressure, but also as negative pressure caused by the flow separation on the corners of the building. Due to the diffidence in the mechanism of wind acting, two typi- cal response cases are classified. The results show that the dynamic response of the structure caused by the negative pressure is stronger than that of the positive pressure case. To determine the aerodynamic wind loading on a flexible part of structure on a building, wind tunnel study may be useful and play an important role.展开更多
The relationship between ship stability and sail area is firstly investigated based on the sail-assisted ship's stability in this paper. Then a height-adjustable sail structure is proposed that could be automatically...The relationship between ship stability and sail area is firstly investigated based on the sail-assisted ship's stability in this paper. Then a height-adjustable sail structure is proposed that could be automatically adjusted according to the wind conditions, ship loading and other requirements. The influences on the sail height in different ship load conditions, different wind apparent velocity and wind direction are analyzed of a sail-assisted bulk carrier. Finally a control procedure of sail height adjustment in real time is proposed according to the actual load conditions, wind conditions, ship velocity and other parameters to make the best use of wind energy, which is significant for the practical application of sail-assisting technology in the future.展开更多
Al-Baha region, located in Saudi Arabia, is one of the main tourism and leisure areas. The authority at Al-Baha Governorate plans to use clean and renewable energy in its tourism facilities. The importance of this stu...Al-Baha region, located in Saudi Arabia, is one of the main tourism and leisure areas. The authority at Al-Baha Governorate plans to use clean and renewable energy in its tourism facilities. The importance of this study is to assess the possibility of building a wind farm in Al-Baha and to select the best site for this purpose. This paper presents an analysis of long-term wind data for the annual and monthly variability in Al-Baha region of southwestern Saudi Arabia. Al-Baha region has an area of 9921 square kilometers and is divided into seven regions (groups) based on their similar measurements and wind speed values. The analysis used 40 years of annual and monthly wind speed data between 1981 and 2020. The analysis showed that Group III has the highest mean wind speed values in the northeastern part of the Al-Baha region, ranging from 5.4 m/s to 5.9 m/s at 50 m above the surface. Group VI (5.1 - 5.6 m/s) east of the Al-Baha area recorded the second-highest mean wind speed, while group V southwest of the Al-Baha area recorded lower values. The maximum wind speeds observed in Group III in January, February, March, and July were 6 m/s or higher. A frequency analysis ensures that 79% of the year’s wind speeds exceed 4 m/s at 50 m above the surface of the Group III site. Wind power was considered for 17 wind turbines of different sizes. The Soyut Wind 500 machine was found to produce maximum energy of 1420 MWh/year. The highest performance values for the Soyut Wind 500 machine occurred in winter and summer, while the calculated capacity factor values at a hub height of 50 m were 41% and 32%, respectively. The assessment concluded that generating electricity from wind at G III in the northeast of the Al-Baha region is a good decision.展开更多
This paper addresses the peak factors of wind- excited responses including alongwind, acrosswind tall building responses and vortex-induced vibration considering the bandwidth parameter. The influence of bandwidth par...This paper addresses the peak factors of wind- excited responses including alongwind, acrosswind tall building responses and vortex-induced vibration considering the bandwidth parameter. The influence of bandwidth parameter on the peak factor is investigated using advanced upcrossing theory taking the bandwidth influence into account. Results show that Davenport's formula without consideration of bandwidth parameter servers well in general. However, the advanced upcrossing theory leads to a better prediction of the peak factor of wind-induced response of very lightly damped buildings.展开更多
基金funded by the Social Science Foundation of Shandong(No.20CXWJ08).
文摘Oil spill prediction is critical for reducing the detrimental impact of oil spills on marine ecosystems,and the wind strong-ly influences the performance of oil spill models.However,the wind drift factor is assumed to be constant or parameterized by linear regression and other methods in existing studies,which may limit the accuracy of the oil spill simulation.A parameterization method for wind drift factor(PMOWDF)based on deep learning,which can effectively extract the time-varying characteristics on a regional scale,is proposed in this paper.The method was adopted to forecast the oil spill in the East China Sea.The discrepancies between predicted positions and actual measurement locations of the drifters are obtained using seasonal statistical analysis.Results reveal that PMOWDF can improve the accuracy of oil spill simulation compared with the traditional method.Furthermore,the parameteriza-tion method is validated with satellite observations of the Sanchi oil spill in 2018.
文摘A weed is a plant that thrives in areas of human disturbance, such as gardens, fields, pastures, waysides, and waste places where it is not intentionally cultivated. Dispersal affects community dynamics and vegetation response to global change. The process of seed disposal is influenced by wind, which plays a crucial role in determining the distance and probability of seed dispersal. Existing models of seed dispersal consider wind direction but fail to incorporate wind intensity. In this paper, a novel seed disposal model was proposed in this paper, incorporating wind intensity based on relevant references. According to various climatic conditions, including temperate, arid, and tropical regions, three specific regions were selected to establish a wind dispersal model that accurately reflects the density function distribution of dispersal distance. Additionally, dandelions growth is influenced by a multitude of factors, encompassing temperature, humidity, climate, and various environmental variables that necessitate meticulous consideration. Based on Factor Analysis model, which completely considers temperature, precipitation, solar radiation, wind, and land carrying capacity, a conclusion is presented, indicating that the growth of seeds is primarily influenced by plant attributes and climate conditions, with the former exerting a relatively stronger impact. Subsequently, the remaining two plants were chosen based on seed weight, yielding consistent conclusion.
基金Projects(51378396,51678452,51708074,2014M560706)supported by General Program of National Natural Science Foundation of ChinaProject(2014M560706)supported by the China Postdoctoral Science Foundation
文摘Wind data were collected during the 2011 typhoon Meari at heights of 10, 20, 30, and 40 m above the ground using a 40 m high anemometer tower in the coastal area near Shanghai Pudong International Airport. Wind speeds and directions, turbulence intensities, gust factors, and peaks were analyzed using the time records of wind speed. The results show that turbulence intensity components in longitudinal, lateral, and vertical directions decrease with mean wind speed, regardless of elevations, and the turbulence intensities are in a linear relationship with mean wind speeds. The ratios of three turbulence intensity components(i.e. Iu, Iv, Iw) at heights of 10, 20 and 40 m were calculated and equal to be 1:0.88:0.50, 1:0.84:0.57, and 1:0.9:0.49, respectively. In addition, the gust factors in three directions exhibit a reduction with increasing mean wind speed. The peak factors at different heights show a similar trend and slightly decrease with mean wind speed; average peak factors for all 10-min data from Typhoon Meari are 2.43, 2.48, and 2.47, respectively.
文摘Improvements in the aerodynamic design will lead to more efficiency of wind turbines and higher power production. In the present study, a 3D parametric gas turbine blade geometry building code, 3DBGB, has been modified in order to include wind turbine design capabilities. This approach enables greater flexibility of the design along with the ability to design more complex geometries with relative ease. The NREL NASA Phase VI wind turbine was considered as a test case for validation and as a baseline by which modified designs could be compared. The design parameters were translated into 3DBGB input to create a 3D model of the wind turbine which can also be imported into any CAD program. Design modifications included replacing the airfoil section and modifying the thickness to chord ratio as a function of span. These models were imported into a high-fidelity CFD package, Fine/TURBO by NUMECA. Fine/TURBO is a specialized CFD platform for turbo-machinery analysis. A code-geomturbo was used to convert the 3D model of the wind turbine into the native format used to define geometries in the Fine/TURBO meshing tool, AutoGrid. The CFD results were post processed using a 3D force analysis code. The radial force variations were found to play a measurable role in the performance of wind turbine blades. The radial component of the blade surface area as it varies in span is the dominant contributor of the radial forces. Through the radial momentum equation, this radial force variation is responsible for creating the streamline curvature that leads to the expansion of the streamtube (slipstream) that is responsible for slowing the wind velocity ahead of the wind turbine leading edge, which is quantified as the axial induction factor. These same radial forces also play a role in changing the slipstream for propellers. Through the design modifications, simulated with CFD and post-processed appropriately, this connection with the radial component of area to the radial forces to the axial induction factor, and finally the wind turbine power is demonstrated. The results from the CFD analysis and 3D force analysis are presented. For the case presented, the power increases by 5.6% due to changes in airfoil thickness only.
基金Supported by National Natural Science Foundation of China(40901136)~~
文摘In this paper,areas and main factors of wind erosion in black earth region of Northeast China were systematically analyzed,as well as the development trend of wind erosion in black earth region of Northeast China.In addition,development trend of wind erosion in black earth region of Northeast China was analyzed from the aspects of the geographic position,climatic change law in recent 40 years and effects of northeast sand land desertification on wind erosion in black earth region,which had provided references for the research and prevention of wind erosion in soil of black earth region of Northeast China.
文摘Multi-phase machines are so attractive for electrical machine designers because of their valuable advantages such as high reliability and fault tolerant ability.Meanwhile,fractional slot concentrated windings(FSCW)are well known because of short end winding length,simple structure,field weakening sufficiency,fault tolerant capability and higher slot fill factor.The five-phase machines equipped with FSCW,are very good candidates for the purpose of designing motors for high reliable applications,like electric cars,major transporting buses,high speed trains and massive trucks.But,in comparison to the general distributed windings,the FSCWs contain high magnetomotive force(MMF)space harmonic contents,which cause unwanted effects on the machine ability,such as localized iron saturation and core losses.This manuscript introduces several new five-phase fractional slot winding layouts,by the means of slot shifting concept in order to design the new types of synchronous reluctance motors(SynRels).In order to examine the proposed winding’s performances,three sample machines are designed as case studies,and analytical study and finite element analysis(FEA)is used for validation.
基金Under the auspices of National Key Technology Research and Development Program of China(No.2011BAC09B08)Special Issue of National Remote Sensing Survey and Assessment of Eco-Environment Change Between 2000 and 2010(No.STSN-04-01)
文摘Using Geographic Information System(GIS), based on wind speed, precipitation, topographic, soil, vegetation coverage and land use data of Inner Mongolia between 2001 and 2010, we applied the revised wind erosion equation(RWEQ) model to simulate wind erosion intensity. The results showed that an area of approximately 47.8 × 10~4 km^2 experienced wind erosion in 2010, 23.2% of this erosion could be rated as severe, and 46.0% as moderate. Both the area and the intensity of wind erosion had decreased from 2001 to 2010, the wind erosion area reduced 10.1%, and wind erosion intensity decreased by 29.4%. Precipitation, wind speed, population size and urbanization in rural areas, and gross domestic product of primary industry(GDP1) were the main factors influencing wind erosion. Overall, these factors accounted for 88.8% of the wind erosion. These results indicated that the decrease in wind erosion over the past decade related to the increase in precipitation and the decrease in the number of windy days, while modest urban development and optimization of the economic structure might partially reduced the level of ecological pressure, highlighting the importance of human activities in controlling wind erosion.
基金supported by the 2013 Doctoral Innovation Funds of Southwest Jiaotong Universitythe Fundamental Research Funds for the Central Universities,the National Key Technology R&D Program of China (2009BAG12A01-C09)the High-Speed Railway Basic Research Fund Key Project (U1234208)
文摘To study the unsteady aerodynamic loads of high-speed trains in fluctuating crosswinds, the fluctuating winds of a moving point shifting with high-speed trains are calculated in this paper based on Cooper theory and harmonic superposition method. The computational fluid dynamics method is used to obtain the aerodynamic load coefficients at different mean yaw angles, and the aero- dynamic admittance function is introduced to calculate unsteady aerodynamic loads of high-speed trains in fluctuating winds. Using this method, the standard deviation and maximum value of the aerodynamic force (moment) are simulated. The results show that when the train speed is fixed, the varying mean wind speeds have large impact on the fluctuating value of the wind speeds and aerodynamic loads; in contrast, when the wind speed is fixed, the varying train speeds have little impact on the fluctuating value of the wind speeds or aerodynamic loads. The ratio of standard deviation to 0.SpKU2, or maximum value to 0.5pKU2, can be expressed as the function of mean yaw angle. The peak factors of the side force and roll moment are the same ( - 3.28), the peak factor of the lift force is - 3.33, and the peak factors of the yaw moment and pitch moment are also the same (- 3.77).
文摘Wind loading study on a cable-net supported glass wall is conducted by means of wind tunnel tests. An equiva- lent aeroelastic model is designed and constructed. Response of displacements of the wall is measured and analyzed. In order to design a glass wall under wind loading, the "wind- vibration factor" is estimated and discussed. In fact, the mech- anism of wind acting on the wall is commonly known not only as positive pressure, but also as negative pressure caused by the flow separation on the corners of the building. Due to the diffidence in the mechanism of wind acting, two typi- cal response cases are classified. The results show that the dynamic response of the structure caused by the negative pressure is stronger than that of the positive pressure case. To determine the aerodynamic wind loading on a flexible part of structure on a building, wind tunnel study may be useful and play an important role.
文摘The relationship between ship stability and sail area is firstly investigated based on the sail-assisted ship's stability in this paper. Then a height-adjustable sail structure is proposed that could be automatically adjusted according to the wind conditions, ship loading and other requirements. The influences on the sail height in different ship load conditions, different wind apparent velocity and wind direction are analyzed of a sail-assisted bulk carrier. Finally a control procedure of sail height adjustment in real time is proposed according to the actual load conditions, wind conditions, ship velocity and other parameters to make the best use of wind energy, which is significant for the practical application of sail-assisting technology in the future.
文摘Al-Baha region, located in Saudi Arabia, is one of the main tourism and leisure areas. The authority at Al-Baha Governorate plans to use clean and renewable energy in its tourism facilities. The importance of this study is to assess the possibility of building a wind farm in Al-Baha and to select the best site for this purpose. This paper presents an analysis of long-term wind data for the annual and monthly variability in Al-Baha region of southwestern Saudi Arabia. Al-Baha region has an area of 9921 square kilometers and is divided into seven regions (groups) based on their similar measurements and wind speed values. The analysis used 40 years of annual and monthly wind speed data between 1981 and 2020. The analysis showed that Group III has the highest mean wind speed values in the northeastern part of the Al-Baha region, ranging from 5.4 m/s to 5.9 m/s at 50 m above the surface. Group VI (5.1 - 5.6 m/s) east of the Al-Baha area recorded the second-highest mean wind speed, while group V southwest of the Al-Baha area recorded lower values. The maximum wind speeds observed in Group III in January, February, March, and July were 6 m/s or higher. A frequency analysis ensures that 79% of the year’s wind speeds exceed 4 m/s at 50 m above the surface of the Group III site. Wind power was considered for 17 wind turbines of different sizes. The Soyut Wind 500 machine was found to produce maximum energy of 1420 MWh/year. The highest performance values for the Soyut Wind 500 machine occurred in winter and summer, while the calculated capacity factor values at a hub height of 50 m were 41% and 32%, respectively. The assessment concluded that generating electricity from wind at G III in the northeast of the Al-Baha region is a good decision.
基金The partial support by the National Science Foundation of China (Grant 51278433) is greatly acknowledged
文摘This paper addresses the peak factors of wind- excited responses including alongwind, acrosswind tall building responses and vortex-induced vibration considering the bandwidth parameter. The influence of bandwidth parameter on the peak factor is investigated using advanced upcrossing theory taking the bandwidth influence into account. Results show that Davenport's formula without consideration of bandwidth parameter servers well in general. However, the advanced upcrossing theory leads to a better prediction of the peak factor of wind-induced response of very lightly damped buildings.