Accurately forecasting the triple point(TP)path is essential for analyzing blast loads and assessing the destructive effectiveness of the height of burst explosion.Empirical models that describe the TP path under norm...Accurately forecasting the triple point(TP)path is essential for analyzing blast loads and assessing the destructive effectiveness of the height of burst explosion.Empirical models that describe the TP path under normal temperature and pressure environments are commonly employed;however,in certain configurations,such as at high-altitudes(HAs),the environment may involve low temperature and pressure conditions.The present study develops a theoretical prediction model for the TP path under reduced pressure and temperature conditions,utilizing the image bursts method,reflected polar analysis,and dimensional analysis.The model's accuracy is evaluated through numerical simulations and experimental data.Results indicate that the prediction model effectively evaluates the TP path under diminished temperature and pressure conditions,with most predictions falling within a±15%deviation.It was found that the TP height increases with altitude.As the altitude rises from 0 m to 10,000 m,the average TP height increases by 61.7%,87.9%,109.0%,and 134.3%for the scaled height of burst of 1.5 m,2.0 m,2.5 m,and 3.0 m,respectively.Moreover,the variation in TP height under HA environments closely mirrors that observed under corresponding reduced pressure conditions.In HA environments,only the effect of low-pressure conditions on the TP path needs to be considered,as the environmental lowtemperature has a minimal effect.展开更多
In the process of 2-D compressional wave propagation in a rock mass with multiple parallel joints along the radian direction normal to the joints, the maximum possible wave amplitude corresponding to the points betwee...In the process of 2-D compressional wave propagation in a rock mass with multiple parallel joints along the radian direction normal to the joints, the maximum possible wave amplitude corresponding to the points between the two adjacent joints in the joint set is controlled by superposition of the multiple transmitted and the reflected waves, measured by the maximum rebound ratio. Parametric studies on the maximum rebound ratio along the radian direction normal to the joints were performed in universal distinct element code. The results show that the maximum rebound ratio is influenced by three factors, i.e., the normalized normal stiffness of joints, the ratio of joint spacing to wavelength and the joint from which the wave rebounds. The relationship between the maximum rebound ratio and the influence factors is generalized into five charts. Those charts can be used as the prediction model for estimating the maximum rebound ratio.展开更多
有效波高数据是研究热带气旋海浪预测方法和反演技术的前提,文章利用中法海洋卫星(China-France oceanography satellite,CFOSAT)波谱仪(surface waves investigation and monitoring,SWIM)高精度有效波高观测数据,校正欧洲中期天气预...有效波高数据是研究热带气旋海浪预测方法和反演技术的前提,文章利用中法海洋卫星(China-France oceanography satellite,CFOSAT)波谱仪(surface waves investigation and monitoring,SWIM)高精度有效波高观测数据,校正欧洲中期天气预报中心(European Center for Medium-range Weather Forecasts,ECMWF)第5代再分析资料(the fifth generation ECMWF reanalysis,ERA5)在高海况下低估有效波高的误差,为构建高精度、大样本量的热带气旋海浪有效波高数据集提供了一种可靠方法。首先,由于ERA5与SWIM数据存在时空分辨率差异,文章利用经纬度变换和反距离加权法空间插值对两种数据进行时空匹配。然后,通过数据对比得到了ERA5误差随SWIM有效波高增大而增大的相关关系,进而使用线性回归方法构建了从ERA5到SWIM的有效波高重构方程。最后,使用两处美国国家数据浮标中心(National Data Buoy Center,NDBC)浮标数据对重构方程进行了验证,对于5m以上海浪,ERA5有效波高数据的均方根误差分别从重构前的1.65m和1.08m降低到重构后的1.18m和0.71m,证明了重构方程的有效性。展开更多
基金funding from Anhui Engineering Laboratory of Explosive Materials and Technology Foundation(No.AHBP2022B-04)Natural Science Research Project of Anhui Educational Committee(No.2023AH051221)+1 种基金Anhui Provincial Natural Science Foundation(No.2208085QA26)Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology for the project related to this work.
文摘Accurately forecasting the triple point(TP)path is essential for analyzing blast loads and assessing the destructive effectiveness of the height of burst explosion.Empirical models that describe the TP path under normal temperature and pressure environments are commonly employed;however,in certain configurations,such as at high-altitudes(HAs),the environment may involve low temperature and pressure conditions.The present study develops a theoretical prediction model for the TP path under reduced pressure and temperature conditions,utilizing the image bursts method,reflected polar analysis,and dimensional analysis.The model's accuracy is evaluated through numerical simulations and experimental data.Results indicate that the prediction model effectively evaluates the TP path under diminished temperature and pressure conditions,with most predictions falling within a±15%deviation.It was found that the TP height increases with altitude.As the altitude rises from 0 m to 10,000 m,the average TP height increases by 61.7%,87.9%,109.0%,and 134.3%for the scaled height of burst of 1.5 m,2.0 m,2.5 m,and 3.0 m,respectively.Moreover,the variation in TP height under HA environments closely mirrors that observed under corresponding reduced pressure conditions.In HA environments,only the effect of low-pressure conditions on the TP path needs to be considered,as the environmental lowtemperature has a minimal effect.
基金Projects(50278057) supported by the National Natural Science Foundation of China project(2002CB412703) supported by Major State Basic Research Development Program of China
文摘In the process of 2-D compressional wave propagation in a rock mass with multiple parallel joints along the radian direction normal to the joints, the maximum possible wave amplitude corresponding to the points between the two adjacent joints in the joint set is controlled by superposition of the multiple transmitted and the reflected waves, measured by the maximum rebound ratio. Parametric studies on the maximum rebound ratio along the radian direction normal to the joints were performed in universal distinct element code. The results show that the maximum rebound ratio is influenced by three factors, i.e., the normalized normal stiffness of joints, the ratio of joint spacing to wavelength and the joint from which the wave rebounds. The relationship between the maximum rebound ratio and the influence factors is generalized into five charts. Those charts can be used as the prediction model for estimating the maximum rebound ratio.
文摘有效波高数据是研究热带气旋海浪预测方法和反演技术的前提,文章利用中法海洋卫星(China-France oceanography satellite,CFOSAT)波谱仪(surface waves investigation and monitoring,SWIM)高精度有效波高观测数据,校正欧洲中期天气预报中心(European Center for Medium-range Weather Forecasts,ECMWF)第5代再分析资料(the fifth generation ECMWF reanalysis,ERA5)在高海况下低估有效波高的误差,为构建高精度、大样本量的热带气旋海浪有效波高数据集提供了一种可靠方法。首先,由于ERA5与SWIM数据存在时空分辨率差异,文章利用经纬度变换和反距离加权法空间插值对两种数据进行时空匹配。然后,通过数据对比得到了ERA5误差随SWIM有效波高增大而增大的相关关系,进而使用线性回归方法构建了从ERA5到SWIM的有效波高重构方程。最后,使用两处美国国家数据浮标中心(National Data Buoy Center,NDBC)浮标数据对重构方程进行了验证,对于5m以上海浪,ERA5有效波高数据的均方根误差分别从重构前的1.65m和1.08m降低到重构后的1.18m和0.71m,证明了重构方程的有效性。
