By combining the results of prototype observation of flood discharge atomization at the Wujiangdu Hydropower Station, and by adopting the serial model test method, the model scale effect was examined, the influences o...By combining the results of prototype observation of flood discharge atomization at the Wujiangdu Hydropower Station, and by adopting the serial model test method, the model scale effect was examined, the influences of the Reynolds and Weber numbers of water flow on the rain intensity of flood discharge atomization were analyzed and a rain intensity conversion relation was established. It is demonstrated that the level of atomization follows the geometric similarity relations and it is possible to ignore the influence of the surface tension of the flow when the Weber number is greater than 500. Despite limitations such as incomplete data sets, it is undoubtedly helpful to study the scale effect of atomization flow, and it is beneficial to identify the rules of the model test results in order to extrapolate to prototype prediction.展开更多
Atomizing rainfall caused by flood discharge of high dams poses a great threat to the safety of powerhouse and ecological environment.As an indispensable means,numerical calculation is widely used in the safety design...Atomizing rainfall caused by flood discharge of high dams poses a great threat to the safety of powerhouse and ecological environment.As an indispensable means,numerical calculation is widely used in the safety design of discharge structures.The distribution of rainfall intensity is closely related to the trajectory nappe shape,jet trajectory distances,the splashed water droplet diameter and its velocity,and the spatial distribution of downstream nappe wind.In this paper,an experimental result is used to verify the improved stochastic splash mathematical model under different bucket types and discharge conditions,and the sensitivity of downstream rainfall intensity distribution to the shape of trajectory nappe,discharge flow,spatial distribution of downstream nappe wind,and the corresponding relationship between the droplet diameter and its splashing velocity is analyzed.The results show that the calculation accuracy of downstream rainfall intensity distribution is significantly improved when the above factors are taken into consideration.It is found that the bucket type and flood discharge rate play the greatest role in the rainfall intensity distribution,followed by the downstream nappe wind distribution,and finally the corresponding relationship between the diameter and velocity of splash droplets.Therefore,these factors should be considered comprehensively when the rainfall intensity distribution of flood discharge atomization is calculated.This study can help us to understand the influence factors of flood discharge atomization more deeply and predict the distribution of flood discharge atomization rainfall intensity more accurately.展开更多
基金supported by the National Natural Science Foundation of China (Grant No 50579084)the Foundation of the Nanjing Hydraulic Research Institute (Grant No Y10705)
文摘By combining the results of prototype observation of flood discharge atomization at the Wujiangdu Hydropower Station, and by adopting the serial model test method, the model scale effect was examined, the influences of the Reynolds and Weber numbers of water flow on the rain intensity of flood discharge atomization were analyzed and a rain intensity conversion relation was established. It is demonstrated that the level of atomization follows the geometric similarity relations and it is possible to ignore the influence of the surface tension of the flow when the Weber number is greater than 500. Despite limitations such as incomplete data sets, it is undoubtedly helpful to study the scale effect of atomization flow, and it is beneficial to identify the rules of the model test results in order to extrapolate to prototype prediction.
基金supported by the National Natural Science Foundation of China(Grant Nos.U1765202,U20A20316,515779167)the Foundation for Innovative Research Groups of the Natural Science Foundation of Hebei Province of China(Grant No.E2020402074)。
文摘Atomizing rainfall caused by flood discharge of high dams poses a great threat to the safety of powerhouse and ecological environment.As an indispensable means,numerical calculation is widely used in the safety design of discharge structures.The distribution of rainfall intensity is closely related to the trajectory nappe shape,jet trajectory distances,the splashed water droplet diameter and its velocity,and the spatial distribution of downstream nappe wind.In this paper,an experimental result is used to verify the improved stochastic splash mathematical model under different bucket types and discharge conditions,and the sensitivity of downstream rainfall intensity distribution to the shape of trajectory nappe,discharge flow,spatial distribution of downstream nappe wind,and the corresponding relationship between the droplet diameter and its splashing velocity is analyzed.The results show that the calculation accuracy of downstream rainfall intensity distribution is significantly improved when the above factors are taken into consideration.It is found that the bucket type and flood discharge rate play the greatest role in the rainfall intensity distribution,followed by the downstream nappe wind distribution,and finally the corresponding relationship between the diameter and velocity of splash droplets.Therefore,these factors should be considered comprehensively when the rainfall intensity distribution of flood discharge atomization is calculated.This study can help us to understand the influence factors of flood discharge atomization more deeply and predict the distribution of flood discharge atomization rainfall intensity more accurately.
