对2015年8月23日发生在陕西关中的一次伴有阵风锋的强对流天气过程的不稳定度条件、卫星云图和雷达资料进行分析,结果表明:本次强对流天气过程虽然发生在槽前,但垂直环境配置为"上干下湿",属于槽前"干"对流,850 h P...对2015年8月23日发生在陕西关中的一次伴有阵风锋的强对流天气过程的不稳定度条件、卫星云图和雷达资料进行分析,结果表明:本次强对流天气过程虽然发生在槽前,但垂直环境配置为"上干下湿",属于槽前"干"对流,850 h Pa的切变线为强对流提供了初始扰动,地面辐合线触发了强对流天气的发生;两条阵风锋均出现在对流云团边缘TBB梯度最大的区域内、对流有效位能剧烈释放时;另外,两条阵风锋的相向运动,导致两条阵风锋之间强对流单体的产生。当强对流云团与阵风锋叠加时,一方面,二者相互抑制,互为削弱,阵风锋很快消散;另一方面,与阵风锋相联系的对流云团中因为有新的对流单体补充又迅速发展,产生更剧烈的强对流天气。展开更多
Heat and mass transfer of a circular-shaped porous moist object inside a two-dimensional triangle cavity is investigated by using finite element method.The porous object is considered to be a moist food sample,located...Heat and mass transfer of a circular-shaped porous moist object inside a two-dimensional triangle cavity is investigated by using finite element method.The porous object is considered to be a moist food sample,located in the middle of the cavity with inlet and outlet ports with different configurations of inlet/outlet ports.Convective drying performance is numerically assessed for different values of Reynolds numbers(between 50 and 250),dry air inlet temperature(between 40 and 80℃)and different locations of the port.It is observed that changing the port locations has significant impacts on the flow recirculaitons inside the triangular chamber while convective drying performance is highly affected.The moisture content reduces with longer time and for higher Reynolds number(Re)values.Case P4 where inlet and outlet ports are in the middle of the walls provides the most effective configuration in terms of convective drying performance while the worst case is seen for P1 case where inlet and outlet are closer to the corners of the chamber.There is a 192% difference between the moisture reduction of these two cases at Re=250,T=80℃ and t=120 min.展开更多
文摘对2015年8月23日发生在陕西关中的一次伴有阵风锋的强对流天气过程的不稳定度条件、卫星云图和雷达资料进行分析,结果表明:本次强对流天气过程虽然发生在槽前,但垂直环境配置为"上干下湿",属于槽前"干"对流,850 h Pa的切变线为强对流提供了初始扰动,地面辐合线触发了强对流天气的发生;两条阵风锋均出现在对流云团边缘TBB梯度最大的区域内、对流有效位能剧烈释放时;另外,两条阵风锋的相向运动,导致两条阵风锋之间强对流单体的产生。当强对流云团与阵风锋叠加时,一方面,二者相互抑制,互为削弱,阵风锋很快消散;另一方面,与阵风锋相联系的对流云团中因为有新的对流单体补充又迅速发展,产生更剧烈的强对流天气。
文摘Heat and mass transfer of a circular-shaped porous moist object inside a two-dimensional triangle cavity is investigated by using finite element method.The porous object is considered to be a moist food sample,located in the middle of the cavity with inlet and outlet ports with different configurations of inlet/outlet ports.Convective drying performance is numerically assessed for different values of Reynolds numbers(between 50 and 250),dry air inlet temperature(between 40 and 80℃)and different locations of the port.It is observed that changing the port locations has significant impacts on the flow recirculaitons inside the triangular chamber while convective drying performance is highly affected.The moisture content reduces with longer time and for higher Reynolds number(Re)values.Case P4 where inlet and outlet ports are in the middle of the walls provides the most effective configuration in terms of convective drying performance while the worst case is seen for P1 case where inlet and outlet are closer to the corners of the chamber.There is a 192% difference between the moisture reduction of these two cases at Re=250,T=80℃ and t=120 min.
