Experimental Study on Aero Conductivity of Porous Media  

作　　者：陈家军 杨官光 刘运武 郑冰 杨建 

机构地区：[1]State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China [2]Hegang Meteorological Bureau, Hegang 154100, China

出　　处：《Journal of China University of Geosciences》2006年第4期332-336,共5页中国地质大学学报（英文版）

基　　金：This paper is supported by the National Natural Science Foundation ofChina(No.40272107)and the Key Research Fund of Ministry of Edu-cation of China(No.104012).

摘　　要：To study the variation pattern of aero conductivity of different porous media under low pressure conditions, three kinds of media are selected. These include sandy clay loam, fine sand, and medium sand, and air us fluid to conduct soil column ventilation tests. Pressure at both ends of the colruns is measured under different ventilation flow rates during testing. The test results show that the aero conductivity, solved by Darcy＇s law, is not a coustant. It is a variable, which increases first when air flow velocity is less than 0. 258 7 cm/s for sandy clay loam, 0. 637 3 cm/s for fine sand and then decreases when air flow velocity is bigger than that with the increase of the ventilation flow rate when the medium is determined. By analyzing various factors that influence the flow resistance, the reasons for variation in aero conductivity are found us follows： first, the change of pore structure results in better ventilation; second, the relatiouship hetwcen pressure head loss and air flow velocity is nonlinear, and it is beyond the condition of the Iminar flow domain to which Darcy＇ s law can he applied, when the air flow rate increases to a certain value and the flow velocity is in the transition range to turbulent flow.To study the variation pattern of aero conductivity of different porous media under low pressure conditions, three kinds of media are selected. These include sandy clay loam, fine sand, and medium sand, and air us fluid to conduct soil column ventilation tests. Pressure at both ends of the colruns is measured under different ventilation flow rates during testing. The test results show that the aero conductivity, solved by Darcy＇s law, is not a coustant. It is a variable, which increases first when air flow velocity is less than 0. 258 7 cm/s for sandy clay loam, 0. 637 3 cm/s for fine sand and then decreases when air flow velocity is bigger than that with the increase of the ventilation flow rate when the medium is determined. By analyzing various factors that influence the flow resistance, the reasons for variation in aero conductivity are found us follows： first, the change of pore structure results in better ventilation; second, the relatiouship hetwcen pressure head loss and air flow velocity is nonlinear, and it is beyond the condition of the Iminar flow domain to which Darcy＇ s law can he applied, when the air flow rate increases to a certain value and the flow velocity is in the transition range to turbulent flow.

关 键 词：aero conductivity Darcy＇ s law pressure head loss nonlinear. 

分 类 号：P641.2[天文地球—地质矿产勘探]