Simulation of wind rain loads of non-stationary non-Gaussian downburst accompanied with rain
Received:October 18, 2017  Revised:January 09, 2018
View Full Text  View/Add Comment  Download reader
DOI:10.7511/jslx20171018002
KeyWord:time-varying power spectrum  downburst accompanied with rain  non-stationary non-Gaussian  impact of raindrop  probability density function
           
AuthorInstitution
李锦华 华东交通大学 土木建筑学院, 南昌
余维光 华东交通大学 土木建筑学院, 南昌
李春祥 上海大学 土木工程系, 上海
管海平 华东交通大学 土木建筑学院, 南昌
Hits: 1350
Download times: 898
Abstract:
      In order to numerically simulate the downburst accompanied with rain,the non-stationary non-Gaussian fluctuating wind speed is generated using the time-varying average wind speed and the modulated kaimal spectrum.Analysis of the results shows that the correlation function of the simulated fluctuating wind speed sample possesses the time-varying characteristics,and the instantaneous correlation function is consistent with the corresponding targets,meaning that the simulated fluctuating wind velocity has the targeted non-stationary characteristics;simultaneously,the probability density function agrees with the objective function,implying that the simulated fluctuating wind speed possesses the targeted non-Gaussian trait.Hence,the proposed simulation method is effective and feasible for the non-stationary non-Gaussian stochastic process.In view of the impact load of raindrop,the impact force of a single raindrop is derived from the motion analysis of a single raindrop.Further,the impact of a single raindrop is extended to the impact of a large number of raindrops using the unit volume raindrop spectrum.Analysis of the results indicates that the wind speed has a great influence on raindrop impact load and the trend of rain load is basically consistent with that of the wind speed,thus implying the impact of raindrops of downburst is mainly caused by its wind speed drag.Likewise,with the increase of rainfall intensity the change tendency of raindrop impact force is practically unchanged,but its peak increases.In addition,by changing the parameter of rainfall intensity,it is found that with the increase of rainfall intensity,the change trend of raindrop impact force is almost invariable,but the peak value increases.