The state-of-art Computational Fluid Dynamics （CFD） codes FLUENT is applied in a fine-scale simulation of the wind field over a complex terrain. Several numerical tests are performed to validate the capability of FL...The state-of-art Computational Fluid Dynamics （CFD） codes FLUENT is applied in a fine-scale simulation of the wind field over a complex terrain. Several numerical tests are performed to validate the capability of FLUENT on describing the wind field details over a complex terrain. The results of the numerical tests show that FLUENT can simulate the wind field over extremely complex terrain, which cannot be simulated by mesoscale models. The reason why FLUENT can cope with extremely complex terrain, which can not be coped with by mesoscale models, relies on some particular techniques adopted by FLUENT, such as computer-aided design （CAD） technique, unstructured grid technique and finite volume method. Compared with mesoscale models, FLUENT can describe terrain in much more accurate details and can provide wind simulation results with higher resolution and more accuracy.展开更多
The accurate three-dimensional wind field obtained from a Doppler lidar not only helps to comprehend the refined structure of complex airflow but also provides important and valuable solutions for many fields.However,...The accurate three-dimensional wind field obtained from a Doppler lidar not only helps to comprehend the refined structure of complex airflow but also provides important and valuable solutions for many fields.However,the underlying homogeneity assumption of the typical wind retrieval methods,such as Doppler Beam Swinging(DBS)and Velocity Azimuth Display(VAD)based on a single-lidar,will introduce the measurement uncertainty in complex terrain.In this paper,a new design of a wind measurement campaign involving seven lidars was carried out,which contained the three-lidar-based Virtual Tower(VT)using a time-space synchronization technique and four single-lidars with different elevation angles.This study investigates the performance of VT and VAD measurements under various conditions and evaluates the sensitivity of wind measurement uncertainty of VAD to the horizontal spatial-and probe volume-average effects associated with elevation angles of the laser beam.The inter-comparison results between VT and four VADs show consistent trends with small relative errors under neutral atmospheric conditions with weak wind velocity.Under convective or high Turbulence Intensity(TI)conditions,the relative errors between VT and VAD become larger and more fluctuant.Moreover,it is found that the measurement uncertainty of VAD increases at a given elevation angle with the increasing measurement heights,which is caused by the horizontal homogeneity associated with the conical scanning area.Additionally,the simulated and measured results of four VADs indicate that a larger elevation angle corresponds to a lower measurement uncertainty for a given height.展开更多
Due to increased demands in transportation development,bridge construction has been extended to areas with complex wind fields.In addition to common flow features such as high wind speeds and strong turbulence intensi...Due to increased demands in transportation development,bridge construction has been extended to areas with complex wind fields.In addition to common flow features such as high wind speeds and strong turbulence intensity,in coastal areas,bridges are likely to be exposed to non-stationary and non-Gaussian high-speed wind fields during hurricane events.Bridges built in mountainous regions will experience varying wind directions,incident angles of attack(AOA),and wind speed variation due to undulating terrain.The complex wind fields are challenging to the bridge engineering community to which accurate calculation methods and suppression measures for bridge vibration are urgently required.In this paper,state-of-the-art research results are introduced through three categories:(a)the distinctive characteristics of complex wind fields in offshore and mountainous areas,(b)the categories of wind-induced vibrations for bridges,and(c)the suppression measures employed in engineering practices.Until now,the studies regarding the coupled bridge vibration in complex wind fields have made considerable progress,but a richer database of actual wind measurement results and more efficient simulation methods still need to be further established.展开更多
基金supported by the National Natural Science Foundation of China(40805004, 40705039 and 90715031)the "Mini-projecton detailed survey and evaluation of wind energy resources"supported by National Climate Center of Chinese Meteoro-logical Administration (CWERA2010002)
文摘The state-of-art Computational Fluid Dynamics （CFD） codes FLUENT is applied in a fine-scale simulation of the wind field over a complex terrain. Several numerical tests are performed to validate the capability of FLUENT on describing the wind field details over a complex terrain. The results of the numerical tests show that FLUENT can simulate the wind field over extremely complex terrain, which cannot be simulated by mesoscale models. The reason why FLUENT can cope with extremely complex terrain, which can not be coped with by mesoscale models, relies on some particular techniques adopted by FLUENT, such as computer-aided design （CAD） technique, unstructured grid technique and finite volume method. Compared with mesoscale models, FLUENT can describe terrain in much more accurate details and can provide wind simulation results with higher resolution and more accuracy.
基金supported by the National Key Research and Development Program of China[grant number 2021YFC3001902,2022YFB3901705]the National Natural Science Foundation of China[grant number 42106182,U2106210]the Natural Science Foundation of Shandong Province[grant number ZR2021QD052].
文摘The accurate three-dimensional wind field obtained from a Doppler lidar not only helps to comprehend the refined structure of complex airflow but also provides important and valuable solutions for many fields.However,the underlying homogeneity assumption of the typical wind retrieval methods,such as Doppler Beam Swinging(DBS)and Velocity Azimuth Display(VAD)based on a single-lidar,will introduce the measurement uncertainty in complex terrain.In this paper,a new design of a wind measurement campaign involving seven lidars was carried out,which contained the three-lidar-based Virtual Tower(VT)using a time-space synchronization technique and four single-lidars with different elevation angles.This study investigates the performance of VT and VAD measurements under various conditions and evaluates the sensitivity of wind measurement uncertainty of VAD to the horizontal spatial-and probe volume-average effects associated with elevation angles of the laser beam.The inter-comparison results between VT and four VADs show consistent trends with small relative errors under neutral atmospheric conditions with weak wind velocity.Under convective or high Turbulence Intensity(TI)conditions,the relative errors between VT and VAD become larger and more fluctuant.Moreover,it is found that the measurement uncertainty of VAD increases at a given elevation angle with the increasing measurement heights,which is caused by the horizontal homogeneity associated with the conical scanning area.Additionally,the simulated and measured results of four VADs indicate that a larger elevation angle corresponds to a lower measurement uncertainty for a given height.
基金The financial support from National Natural Science Foundation of China(Grant No.52078425)。
文摘Due to increased demands in transportation development,bridge construction has been extended to areas with complex wind fields.In addition to common flow features such as high wind speeds and strong turbulence intensity,in coastal areas,bridges are likely to be exposed to non-stationary and non-Gaussian high-speed wind fields during hurricane events.Bridges built in mountainous regions will experience varying wind directions,incident angles of attack(AOA),and wind speed variation due to undulating terrain.The complex wind fields are challenging to the bridge engineering community to which accurate calculation methods and suppression measures for bridge vibration are urgently required.In this paper,state-of-the-art research results are introduced through three categories:(a)the distinctive characteristics of complex wind fields in offshore and mountainous areas,(b)the categories of wind-induced vibrations for bridges,and(c)the suppression measures employed in engineering practices.Until now,the studies regarding the coupled bridge vibration in complex wind fields have made considerable progress,but a richer database of actual wind measurement results and more efficient simulation methods still need to be further established.
